Not too long ago we had an interesting case of an elderly male patient who developed a DVT after an injury to the leg with subsequent immobility. The crux of the case was that access to medical care was severely limited by an ongoing conflict and availability of medications. It all worked out in the end, but along the way there were a handful of interesting discussions and a number of learning points. So let’s dive in.

Case Summary:

Day 1: Summoned to see a 70-year-old male who presented with swelling in the right foot. Status post injury with likely fracture one month prior (says that no imaging was done at that time), however swelling was new for the past five days. Stated he had been relatively immobile since the injury, but does walk as needed with a cane. Right leg is tender to touch, slightly cooler than left, swollen but non-pitting, discolored/ bruised. Negative Homan’s sign.

Hx: DM, HTN

Meds: ASA, anti-hypertensive, metformin

Also had been taking both Paracetamol and Ibuprofen PRN.

No respiratory symptoms. Well’s for PE low, Well’s for DVT moderate.

MDCalc for Well’s DVT

MDCalc for Well’s PE

EKG showed SR 90s, pre-existing LBBB, negative Sgarbossa. POCUS not available at this time.

Failed to keep a copy of the full 12-lead… Also see our 12-Lead EKG Reference via the Protocols & Cheat Sheets page on our site for a review of all that.

Day 2: Ultrasound showed non-compressible femoral vein with clot seen inside vessel. Extends from inguinal fold to mid-thigh.

Initial Scan - shows non-compressible femoral vein and clot within vessel lumen

Second Scan - same thing, just slightly better view and a bit slower

Scan of Popliteal area - just to show what the distal bit of the scan looked like

Normally this patient would be referred to the hospital, but that was not possible due to the danger involved with travel. On hand was Heparin 25,000u x1 vial (med bag stock) and Clopidogrel 75mg x30 tabs (patient had acquired “blood thinner” just in case).

Decision made to treat now with 1/2 of the available Heparin SQ (12,500u) and attempt to obtain appropriate agents. Remainder of Heparin to be given that evening as another 12,500u SQ dose while a plan was put in place to source appropriate medications. Clopidogrel not utilized.

Patient’s family was able to acquire Lovenox 80mg/ 8000IE SQ prefill syringes. Treatment initiated that evening.

Day 3: Second dose of Lovenox given that morning. Family instructed in administration in order to continue with the regimen. Plan was to proceed with Lovenox BID until PO meds could be acquired.

Ongoing effort initiated to procure DOAC (either Rivaroxaban or Apixiban) for prolonged treatment.

Resolution: DOAC was eventually acquired and patient transitioned from SQ Lovenox to PO agent after about a week. Repeat US showed clot decreasing in size and no complications reported.

Initial Questions:

Of the available options on Day 2, was treatment with Heparin the best decision?

In the absence of a better way to look into this question, I copied the above case outline into OpenEvidence after the fact and got this reply.

Seems like that was a reasonable course of action, so long as we acknowledge that the heparin dosing wasn’t ideal. We could have considered one full-strength dose vs planned for two sub-therapeutic doses.

Also worth mentioning that giving heparin in the field and without the ability to monitor aPTT levels is suboptimal.

That said, the risk of the big complication (Heparin Induced Thrombocytopenia or “HIT”) with one or two doses is assumed to be quite low, as normally we see it develop after a prolonged course (i.e., >5 days) and more often with IV Heparin (vs. SQ).

Read more on HIT here

And then what could have been done to avoid complications while a treatment plan was developed? Let’s say no appropriate anticoagulants were available?

Turns out there are a few things: compression, limb elevation (when at rest) and early ambulation.

Compression: wrap from the ankle to the knee (i.e., cover the calf muscle) with decreasing tension (i.e., wrap tighter at the foot/ ankle and less tight proximally); ACE bandage is an OK option that most EMS folks would have access to, other elastic bandages may be better; no need to cover the thigh/ clot itself, as the mechanism hinges on calf muscle function to resolve edema and improve blood flow; maintain compression until transition out of the austere setting (may be utilized long-term), will likely require regular re-application with patient movement.

Discussion of benefit

Discussion on knee-length vs. thigh-length compression

Limb elevation: while at rest, keep the affected limb elevated when possible; this facilitates venous drainage and reduces swelling/ pressure.

[Physiologically sound and more or less universally accepted, no direct data on benefit in DVT, especially in the absence of concurrent pharmacologic therapy; that said, very low risk and reasonable to do.]

Ambulation: move the body early; this can be ambulation or passive range of motion exercises (for patients who are immobile); the risk of “breaking up a clot” and causing a pulmonary embolism is not generally a thing (except in the uncommon incidence of a free floating thrombus) and most clinical guidelines now recommend activity over bedrest.

Discussion of bed rest vs. early ambulation

Discussion of exercise after DVT

Free floating thrombus (also note that this free-floating thing can be appreciated on ultrasound)

Further Learning:

Brief Overview of Homan’s Sign

Article on Diagnosing DVT that Covers Well’s Scores

POCUSGeeks Video on Ultrasound for DVT

Comprehensive Overview of Anticoagulation

Follow-Up Considerations:

How reasonable is it to carry Heparin in the prehospital/ out-of hospital setting?

There’s pretty good evidence for benefit of prehospital use in acute myocardial infarction: see HEPARIN STEMI Trial

And there’s been some discussion over the years about prehospital use of heparin for pulmonary embolism: article in EMS World that mentions this

Which seems like a fair extension of data from the ER setting: Early Anticoagulation and Reduced Mortality in PE

Other potential use cases would be acute limb ischemia or atrial fibrillation with an observed embolus (for the POCUS folks). Maybe also a bit of a stretch use case in frostbite for those located in remote and cold areas that also have thrombolytics.

In summary, it seems like prehospital Heparin makes more sense the further we get from definitive care and the more advanced our scope of practice (i.e., ultrasound, thrombolytics, etc.). Probably not all that relevant for most EMS agencies.

How likely is a DVT to develop in an austere setting, such as in prolonged field care or after a backcountry injury that leaves someone immobile while pending evacuation?

As above, I simply fed this question to OpenEvidence and here’s what they had to say.

TL;DR is that dehydration, TXA use and the nature of injuries seen in these setting (multi-system trauma and lower extremity injuries) all contribute to DVT risk.

So definitely a concern and for sure something to think about.

On that note, there is some discussion of DVT prevention in Nursing Intervention in Prolonged Field Care - worth a review of specific techniques outlined there.

Basically take care to mitigate the risk of developing a DVT with physical movement when resources allow, saves the trouble of having to treat the thing later on.

Summary:

DVT is one of those things that we don’t focus on much in the EMS setting where hospital-based definitive care is readily accessible, but in the austere setting it is more likely to come up. Diagnosis can be narrowed in on via clinical history and physical exam, and then confirmed by ultrasound. As for treatment: while anticoagulation is eventually needed, there are a few other things that can be done by medics in the field until that becomes available or concurrently.

As always and forever, let us know if you have any questions or feedback!

This patient was an 81-year-old male with history of DMII, HTN, CKD IV & MI (with 11 stents and a 4x bypass, plus an AICD in place) and who presented to the ER with “general illness.” He described sore throat and cough for one week, along with exertional dyspnea.

Workup revealed an abnormal EKG reported as wide complex tachycardia in the 110s with an intermittent narrow complex rhythm. BGL was elevated at over 400, but without evidence of DKA. Patient was noted to be hypotensive and eventually required both fluids and a vasopressor (Norepinephrine at 5mcg/min). He was also treated for community acquired pneumonia. Patient was being transferred for cardiology workup.

This was the EKG that the crew was provided with:

Initial observations on this EKG:

• rate: 110s
• rhythm: regular
• p waves: not seen
• PR interval: n/a
• QRS: wide at .20s
• ST segments: ST depression in inferior leads
• T waves: mostly upright where they’re supposed to be, more or less normal, except for V3 that looks a bit weird

And then here’s a zoom-in on that top-left corner where most of the things are notated:

And one more image to try and identify the J-point and any ST changes in different leads. There is some potential, but unconvincing ST elevation in V2 and V3. It looks more like the ST segment itself is inclined or distorted. Not really sure what to make of that, but no need to get caught up there.

Initial thoughts:

• no p-waves seen, but likely supraventricular in nature (i.e, not ventricular)
• bundle branch block (BBB) present
• possible ischemia with ST depression noted in inferior leads, but with concurrent BBB so that changes things a bit; maybe ST elevation in V2-V3; crew going to a PCI center anyways, so no need to delay on scene to think on it
• no need for immediate action or to change treatment plan

Report received was that EKG varied between this wide-complex rhythm and a narrow rhythm at the same rate, but that was not witnessed by crew.

Patient was alert and oriented, required a few liters of oxygen to maintain an SpO2 in the 90s, was hemodynamically stable on Norepinephrine at 5mcg/min.

That said, while en route there were a few things to consider:

• How to describe this rhythm?
• Which flavor of BBB is this? And does it matter?
• What to make of the ST depressions in the inferior leads?
• Is there anything else to be gleaned from the tracing?

To facilitate this investigation, the EKG was scanned into the PMCardio app. Which is a relatively new tool developed by the folks over at Dr. Smith’s EKG Blog. It uses a proprietary AI called The Queen of Hearts to identify OMI. Super rad and free to use, albeit in a limited capacity. Here’s the result:

(This is also how we got the clean digital representation of the EKG scan we were given, just took a photo and PMCardio app did the magic.)

The rhythm interpretation itself (noted at the bottom) seemed fine and reasonable, although it isn’t 100% clear how to for sure identify the thing as a sinus rhythm without discernible p-waves.

As for the BBB, the strip was identified as right-sided BBB (RBBB) with left posterior fascicular block (LPFB). Which, to be honest, is one of those things most EMS people (myself included…) don’t care too much about or know how to identify. So to fact check the PMCardio/ Queen of Hearts interpretation, this handy 12-lead EKG Cheat Sheet was used as a reference:

Specifically, this part on BBBs:

And just to be clear, that graphic that was included in the 12-lead reference is taken from Dubin’s EKG book. But don’t buy a copy, just borrow it off the internet…

As for the hemiblock noted in the automated interpretation, this is something often overlooked in the prehospital setting and perhaps best left to references or after-the-fact analysis. But the Q1S3 pattern for an anterior hemiblock or S1Q3 for posterior can be reviewed here:

(As a sidenote: the plan is to include a graphic like this in the next version of that 12-lead EKG reference, as this case fleshed out that it was missing…)

And for a full discussion of all the ins and outs of fascicular blocks, take a look here: Elzari, 2019

The AI calls it a RBB with LPFB, but not all of the findings we would expect are seen in the tracing:

That said, the pattern for RBBB + LPFB isn’t simply the stuff for RBBB plus the stuff for LPFB, as they interact a bit. Rather, it looks like this:

And then digging deeper into this, it does seem that a Q-wave in lead III is generally required for a diagnosis of LPFB. See Perez-Reira, 2018 for more on that idea. So either we have a very small Q-wave that we just can’t see or there is some other explanation for the rightward axis. Most likely would be right ventricular hypertrophy (RVH) due to some sort of chronic lung condition. Most often this is seen in V1 and V6:

Fairly convincing in this example. Which would mean maybe not a bifascicular block, but rather RBBB + RVH. But no history of lung stuff was reported and it is unlikely that an elderly male has an undiagnosed congenital condition that would predispose him to RVH. He does, however, have both HTN & DMII (and is currently hyperglycemic, so likely not well-controlled) and there is quite a strong correlation between those things and RV dysfunction (as explained by Zhang & friends, 2024).

While at this point it is purely academic (since the patient was relatively stable and was being taken to a center with PCI for further testing by cardiology), let’s assume that the interpretation of RBBB + LPFB is true and discuss what that means.

There are three main conduction pathways through the ventricles: RBB, anterior fascicle of the of LBB, and posterior fascicle of LBB). If two of three of those were blocked (i.e., have inadequate perfusion and, therefore, are non-functioning) this would be quite a significant finding. In addition, the LPF is generally considered more robust than the LAF because it is larger/ wider and has a redundant blood supply:

In this case it has been posited both the RBB and the LPF were blocked. Which is quite rare. And also pretty tenuous if it’s a new-onset thing.

One other fact that was passed on in patient report was that this wide-complex rhythm was intermittent. In hindsight, it may have been a good idea to request additional EKG tracings or press for more details. Specifically, was the change from wide to narrow rate-dependent? More on that idea of a rate-dependent BBB here.

Next thing to consider are those ST changes. In general, ST changes can be tough to interpret when there is a concurrent BBB. With new-onset LBBB, there are the Sgarbossa criteria:

But for RBBB, with or without hemiblock, ST changes are typically assessed as they would be in any other EKG (i.e., same as in the absence of a BBB) with one major caveat: ST depression may be seen in V1-V3. To expand just a bit, discordant ST depression and/ or T-wave inversion can be caused by changes in depolarization/ repolarization. This idea is discussed both in this article by LITFL and this one by EMCases

So there’s a good chance that the ST depression seen in this example is not due to ischemia, but rather a consequence of the conduction abnormality. That said, if there is malperfusion to part of the conduction system, there very well may be impaired perfusion to part to the muscle of the heart itself also. This is why a high index of suspicion is warranted with new-onset BBBs in general.

Moving on and reviewing a bit of physiology, perfusion to the conduction system can be grossly oversimplified as so:

If the RBBB and the LPF were both blocked, it would correlate to the both the RCA and the LAD being affected. At least in this rudimentary framework. Even though there could be some variation to this pattern or collateral flow to accommodate for inadequate bloodflow, the potential for MI, abnormal cardiac function and acute heart failure (HF) here would be high.

On that note - one cool thing noted on the PMCardio interpretation is this “LVSense” note: “reduced LVEF less than or equal to 40% detected.”

While this is still a concept in process with ongoing research, the idea is that AI can extrapolate a left ventricular ejection fraction (LVEF) based on the EKG tracing. There have been papers, such as this one from Bhattarai & friends, 2024 that look at correlating EKG findings to an estimate of EF. But newer studies, like this one by Carter & friends, 2026 look to outsource this analysis to AI models.

(This was the pre-print/ before-peer-review version of a 2025 paper, it’s just that the newer version is not freely available, so we linked this one. If anyone has access, let us know and we’ll update it here. Also academic paper should be free…)

In reference to the case at hand, the LVEF less than 40% correlates clinically - the patient needed hemodynamic support with Norepinephrine to maintain his BP. What isn’t clear is if there was an appreciable change from the patient’s baseline, narrow-complex rhythm. It would have been interesting to see what the LVSense said for that rhythm as a point of comparison.

Regardless, the patient was still in a state of acute HF, maybe also had some component of chronic HF as well. Even if we ignore the LVSense part of things, the patient had an extensive medical history with prior MI, required oxygen and vasopressors, and had conduction abnormalities on his EKG. Even though there was no overt evidence of ischemia or infarct, cardiac function was compromised.

In terms of treatment for this patient, care provided in transport was supportive - maintenance of oxygen and Norepinephrine, monitoring for further decompensation, etc. It is possible that the patient’s acute illness/ infection in the setting of cardiovascular disease and pre-existing HF resulted in the abnormal EKG seen (i.e., an acute change related to increased demand/ workload). While an in-depth analysis of the patient’s EKG didn’t necessarily change the plan of care, it does provide some interesting insight into both the pathology of conduction issue and the use of technology to evaluate EKGs in general.

For those interested in this sort of thing:

• Rykerr Medical’s 12-lead EKG Cheat Sheet can be found here:
  • Download PDF
  • View in-browser
  • Protocols & Cheat Sheets page on the website
• PMCardio App
  • Website
  • App on Apple
  • App on Android
• EKG references in general
  • Dr. Smith’s EKG Blog
  • ECG Waves
  • ECG Book

The patient was a 4-year-old female being transferred out of a conflict zone for care in another recipient country. Patient had known history of Tetralogy of Fallot (ToF), needing follow-up care with pediatric cardiology unavailable in host country.

She was being transported by another ambulance crew in a convoy of many ambulances, multiple patients were being transferred out of the region. While holding the convoy’s position at a safe crossing point, med crew was summoned to check in on this patient.

Patient was stable on assessment, no distress and no cyanosis, but hypotensive and with a low SpO2 at both right hand at the foot. The other crew that had transported the patient up to this point had already initiated oxygen at 1lpm.

Now the goal of treatment was to ensure that the patient was and would be stable enough to make it across the border and to a receiving ambulance on the other side. There was some concern that if care needed to be escalated (i.e., with pressors or any form a machine-assisted ventilatory support - anything beyond a nasal canula) she could lose her ability to be evacuated.

There wasn’t much available in terms of medical history. ToF was a known diagnosis, but there was no information about surgeries or baseline oxygen saturation or known complications.

The decision was made to administer IV fluids in 100ml increments (which was just shy of 10ml/kg) to support her blood pressure and to discontinue oxygen to both establish a baseline and limit unnecessary treatment (to improve the chance of success in getting her across the border).

Now the patient did just fine on ambient air and the blood pressure improved with fluid boluses (three in total). She was, in fact, able to cross and exit out of the region without issue. SpO2 stayed in the 80s, did not cross below 80; it also did not get above 89. Beyond that, there is no way of knowing more about her outcome.

Questions during and after the case included the following:

• Does the concern for oxygen causing closure of the PDA still persist at 4 years?
• And when is it justified to give oxygen to a patient with ToF/ in a case like this?
• Is there a normal SpO2 range for this sort of thing? It is likely highly variable and based on patient’s specific history, but is there a ballpark for when this is not known?
• How much caution is needed with IV fluids in ToF?

Now before diving in to all the details, a quick review of the pathophysiology:

(these sorts of stick figure graphics to describe hemodynamic states are discussed in another blog post: Hemodynamic Sketches)

ToF is composed of the following four things, all present at birth: ventral septal defect (VSD), pulmonary stenosis, right ventricular hypertrophy, and overriding aorta (which means the aorta’s origin/ blood flow comes from overtop the VSD, not just from the left ventricle as is normal). The result is that blood going out to the body is mixed or not fully oxygenated, hence ToF is considered a cyanotic heart lesion or defect.

Now the pulmonary stenosis part of this means that blood flow out of the right ventricle to the pulmonary artery is limited. There is some collateral flow from the aorta via the PDA to the pulmonary artery (left-to-right shunt). Classic teaching is that oxygen given to “ductal-dependent lesions” can cause premature closure of the PDA and worsen outcomes

Normally the ductus arteriosus closes at birth. It is designated a PDA when needed for survival (i.e., a “ductal-dependent lesion”) or when it persists into adulthood. Now in this case with a pink (well-perfused) 4-year-old and the benefit of hindsight, it is most likely that the PDA associated with her ToF has long-since closed. While it could be the case that she had surgery to keep it patent, that is unlikely in the absence of cyanosis, especially at this age. It could be assumed that her case sits left-of-center on this graphic representing the spectrum of ToF:

So withholding oxygen to prevent the closure of a PDA in this case wasn’t necessarily the right move – it would have been totally fine to give oxygen if needed. That said, SpO2 change with supplemental oxygen would be dependent on the severity of the disease and there may not have been much of a change with more oxygen. She was on 1lpm at the start and maintained those low sats on ambient air, but could have had a better SpO2 with more oxygen.

As far as normal ranges or a goal to target in the absence of a solid history, it is highly variable. There is some literature suggesting SpO2 as low as the 70s is “normal” for a ToF case, but beyond that it is difficult to identify an SpO2 goal. That said, the alternative is to use different assessment parameters: color, capillary refill, mentation, etc. - all of which were OK in this case.

And then the last question was in reference to fluid boluses in a case like this. Treatment was started at just under 10ml/kg simply to avoid fluid overload. This is always a reasonable strategy when in doubt, but it’s also worthwhile to try and better understand the pathophysiology and potential risks.

The concern with fluid overload and fluid boluses is more an issue with inadequate left heart function. If the left ventricle can’t move fluid out or if systemic vascular resistance is super high and it’s tough for the left side to push things into it, this could result in pulmonary edema. But in this case, ToF is more of a right-side issue and, in fact, fluid is generally well tolerated. Especially in milder or “pink” cases. While it’s always OK to give fluids slower if in doubt, treatment here was probably overly cautious.

And that’s it. One other thing worth reviewing for the treatment of ToF are “tet spells” or acute episodes of severe cyanosis, but that’s a homework assignment and not a today discussion.

References:

Wilson & friends, 2019

^overview & the pink-to-blue graphic

Vanderlaan & friends, 2023

^normal tx for ToF

Bertanou & friends, 1978

^old paper, life expectancy w/o sx

It’s been quite a long time since I was a brand-new hire in a flight program and almost five years since my most recent new-hire experience, but I’ve recently been thinking quite a bit about the process of being a new guy in this setting. Part of that reason is that I’ve been flying a lot less in the past year than I have in the preceding years and I’ve been feeling a bit out of practice. I’ve had the sense that I may need to reengage with some of the things I used to do when I was green in the field. And while I’m at it, maybe there’s some value to others if I share the details of that process.

One of the toughest parts about starting out in the flight world is learning protocols. This is true for folks who have never flown before, but also relevant when moving between programs. In particular, it’s the drug doses that have always seemed the most important. While it’s more or less acceptable these days to check doses on the phone as needed, I’ve always been of the mindset that its worth memorizing the important and commonly used ones. To help with that, I put together notecards for my drug doses. I have these notecards on an app on my phone called AlgoApp (formerly AnkiApp). I’ve also copied them into a similar app called Brainscape. If you’re interested, check them out here:

Download files for AlgoApp (requires a bit of work to upload into your own account; if that doesn’t work, just get in touch with an email and I can send a link directly)

Download deck directly from Brainscape

And for what it’s worth: I prefer AlgoApp/ AnkiApp for my own use because the formatting looks better and has some nice extra features, but Brainscape is much easier to share between/ amongst folks because it allows you to create links directly to decks.

I built these cards the last time I came back to flight, almost five years ago, but haven’t used them much in the past few years. That said, I’ve now taken the time to update them, check for errors, and now they are there for me to use as needed.

Another potential strategy for learning protocols and the specifics beyond just the drug doses is creating “scripts” as discussed ages back in one of my first podcasts with my good friend Richard:

Scripts Discussion with Richard

While I never did this with all my protocols as Richard describes, I did create a script for rapid sequence intubation (RSI):

Old RSI Procedure Narrative

I had every intention at that time (which was 2021 or so) to do something similar for other high-risk, low-frequency procedures, but I never did get around to it. As a way to re-engage with this process, however, I’ve created a few more of them while writing this. The difference being that these are more generalized and less specific to one job setting, as I now spend a lot of my time outside of the flight job, in settings where a specific kit or bag is not always guaranteed.

RSI Script

Chest Tube Script

Cric Script

The way I used to engage with the one RSI script that I did build back then was to listen to it occasionally on my drive to work. That said, I think most of the value was in creating the thing and spelling out each and every step explicitly. This is to say that just listening to my recordings likely doesn’t offer much benefit, rather they are just here as examples for what you can do yourself.

And while this is something that I’ll probably never take the time to do, a video version of the thing would probably be even higher yield, as coordinating the physical movements and actions with other humans is a key component to actually doing the thing in real life.

Moving on, one other thing that most new clinicians are great at and that I have grown lax with is knowing where precisely every piece of gear lives on the unit (helicopter, in my case). I’ve always been a bit OCD about daily checks, but with time it’s seemed to have shifted to just checking the main cabin and not the stuff in the back. Or just quickly laying eyes on the macro components, but not opening each specific pouch.

It’s also true that things change over time. How the aircraft is set up now is different than how it was when I started. And there are good reasons for this: best practices change, setups get modified for new equipment, now folks at a base have different preferences, arbitrary changes from above, etc.

So the thought experiment here is how to re-ingrain gear/ kit organization in my mind so that I don’t reach for where things used to be. One thought was to identify very specific patient cases in which I’d have to use certain things and map out where’d I’d go. Sort of revisit the script concept in a slightly different context.

So for example: Let’s say we have an OB case with imminent delivery. Which bag does the OB kit live in? Or the doppler? And which pocket in that bag for each?

And the baby is delivered, but needs ventilatory support. How deep down in that main bag is the infant BVM? And where are all the miscellaneous pieces to set up the HFNC system if we want to go that route?

Then for creativity’s sake, let’s say we break down and an EMP takes out our EZ-IO and we live in a world where we won’t get fired for catheterizing an umbilical vein - where do I find the closest 6F feeding tube and an IV start kit? Is there one in these bags I already have open or do I go to where I usually grab one of these things? And what can I use to tie off the stump after the line has been placed to prevent bleeding?

Umbilical Vein Catheterization Reference

(More on that idea on the website at the Protocols & Cheat Sheets page)

And now! Let’s say mom is bleeding real bad. Which side flap of the med pouch has the TXA? And in which row? Because I want the helpful first responders on scene to both get the drug quickly for me and recognize that I know my gear.

Etc. This sort of thing. Except I actually answer all the questions instead of just pointing out what I think I should know.

And also I can work through the process in different settings, depending on where I am working at a given time.

Next thing: I linked above to a document I made for a totally different flight program years ago. It’s an abridged version of protocols/ treatment guidelines we had, designed to be a quick reference for use in the field. I still keep a few of the sections from that document printed out and in my flight suit, I just have edited the specifics to reflect my current program’s guidance:

I haven’t updated that for quite a while, but now it’s in the works. I also have been sitting on a few updates to the collection and have finally made time to finish them:

External Fetal Monitoring

12-lead EKG Interpretation

So here’s what it looks like now:

Part of the reason, I think, why all of this (not just the reference guide thing just described, but also the notecards and scripts and pretend scenarios - the whole thing) takes so much effort is that the pressure to perform well, that eustress that most new flight clinicians feel, just doesn’t exist for experienced folks after some time. Nobody quizzes us on things, nobody questions us, nobody holds us accountable, etc. Which is fine and it all makes sense to some degree, but it creates an environment in which it is very easy to become complacent.

So there you have it. A few things I’m doing to get back to being an above-average employee at my part-time flight job :)

This here write-up is to accompany the video we’ve posted about how our Rykerr Medical Podcast is hosted using free resources out there on the internet. It is a bit complicated, since there are multiple components and some technical computer stuff, but we think it’s pretty cool and worth sharing. Plus it lets anyone host a podcast without having to pay a third party to manage the thing. There’s some stuff here that’s not directly covered in the video and vice versa, so check the video out also.

A bit of background on this concept to get started. Also just know that we have zero technical training in this sort of thing, so the explanation here is just how it seems to us while writing this. A podcast works via a stream of information called an RSS feed. The RSS feed is directed by and based on a piece of code called an xml file. Podcasting services can read and share the contents of an RSS feed so that end-users can consume whatever content is presented in that feed. The idea is that the RSS feed itself is generic and can be shared across different platforms.

For this whole thing to work we need to make an xml file and then host it onto the internet somehow. Once that xml file is live in the ether, it is now an RSS feed that we can plug into a podcast host (such as Apple Podcasts or Spotify). One other consideration, however, is that different hosts have specific rules on how an RSS feed/ xml file needs to be formatted. While there is a consensus at the macro level, certain hosts have individual requirements.

So in order to get this thing to work, we need to the following components: audio files and photos hosted on the internet in a way that our RSS feed can access them, a live xml file (also hosted somewhere on the internet), and an xml files that adheres to the rules of both RSS in general and hosts in particular. And we’re going to make all of this happen on a budget of $0 assuming we already have a computer and some time. Along the way we’ll point out free options for all the necessary components/ intermediary steps.

Now there are many ways to host podcasts for free, but the value in managing one’s own RSS feed is that we are no longer dependent on a third-party host and can opt out of both ads and arbitrary rules. It also allows the creator to port the whole project from one host to another if systems change or if a company goes away without having to rebuild the whole thing.

Last thing before jumping in: we stumbled across this system via a lot of trial and error and with the help of ChatGPT. Computer stuff is not our forte, but we knew what end-goal we wanted and were vaguely familiar with the larger components. There is probably a lot of room for refinement, but we think it works pretty well as is. Feel free to let us know if you see any way we can improve the workflow or system.

Now let’s make it happen.

First step is to sign up for account on both archive.org and github.org using whatever email address you want to be affiliated with the thing. We obviously used our @rykerrmedical.com address since that’s the email used for all the things on this project. If you need a free option, we’ve used both gmail and proton in the past and either would work just fine.

Archive.org is the service we use to get our files up onto the internet. Once the account is created and verified, just log in and there will be an option in the top-right to upload files. Archive.org can be used to host all different types of files, but we use it for photos (jpeg) and audio files (mp3) for the podcast thing. We upload the content for each episode in a single bundle, i.e. the photo and the audio file in the same page - this allows us to use the resulting page on archive.org as the podcast episode webpage in our RSS feed or xml file (more on that later). If that isn’t clear, refer to the video to see how it works.

If you want your podcast to make its way onto all the various podcast feeds, it makes the most sense to follow the rules set forth by Apple Podcasts, as they are the most specific. One rule they have is that photos need to be square and at least 1400 x 1400 pixels and no larger than 3000 x 3000. We can do this either on an iPhone (cropping in the photos app, compressing to a given size using an app called Compress) or on a computer (Mac or Windows) using open-source software called GIMP. There are many ways to resize and crop photos, but that’s how we get it done.

When we want to play around with images or combine photos, we aren’t committed to one specific piece of software and use any combination of the following (which, of course, are all available for free): Adobe Express (on iPhone), GIMP (on Mac), PowerPoint (on Mac) and Sketchbook (on iPad). We use these things for all kinds of illustrations, just to be clear, not just the podcast cover photos.

As for the audio file, we do most of recording, editing, and mixing using another open-source program called Audacity. We have also used Spotify for Podcasters (back when it was Anchor.fm and Zoom. Unfortunately the call recording feature that defined Anchor.fm went away when Spotify took over, so that’s sad. And Zoom is kind of lame and not free, but allows us to capture video…. There is, however, a free option called Jitsi that we hope to trial soon. And lastly there is an iPhone app called “voice recorder” that is very similar to the default “voice memo” app on iPhone, but allows you to save and send recordings as mp3 files which saves one step of needing to convert the file.

So that’s how we get the audio files and photos sorted and prepped and uploaded onto the internet. There are many free options for hosting on the internet (such as OneDrive and GoogleDrive), but archive.org has a few unique features that make it suitable for the podcast thing. First is that each episode of the podcast ends up with its own page on archive.org and this (hopefully and in alignment with the mission of the archive.org non-profit) is a way to preserve content for posterity’s sake. Second and most important is that archive.org hosts files with a URL that prompts a direct download of the file it directs to and supports something called “head requests” which allows the end-host (i.e., Apple Podcasts or Spotify) to verify the thing. That’s the extent of our understanding and we learned it from ChatGPT when hosting files other ways didn’t work…. That said, there may be other ways to host the files, but we think archive.org is rad and that’s what we’ve opted to stick with.

Alrighty, so now we have made the audio files and built our graphics and have them saved on archive.org (for free and forever). Next step is to build the RSS feed itself over at github.org. As a quick aside: github isn’t necessarily designed for this, rather it serves as a way for folks to host code and collaborate with other developers. That said, there are lots of what we’d call off-label uses of github, and this is simply another one of those. Heads up though: this part has some specific instructions and can be a little confusing. It took us many tries and a number of long talks with ChatGPT to figure this all out.

We’ll set the thing up in a web browser, but once that’s done you can do subsequent steps (i.e., publish episodes and modify the xml file/ RSS feed) from any device. Log into your github account. Create a repository and label it “landing.” Create a “readme” file when github prompts you to do so, feel free to add descriptive text in here as you see fit, then “commit changes.” After that, click on “landing” at the top, then on the “+” symbol to create a new file, label it as “feed.xml.” And then do the same thing over to create another file named “index.html.” To be 100% honest, it’s not totally clear if the readme part is necessary, but since github prompts you to do it and it’s simple, seemed like the right decision. The other two parts, however, are both necessary – we absolutely do need an index.html and feed.xml for this to work.

Now that our repository and the pages are done, we need to build the code of the xml file which is the technical piece of our RSS feed. In either a web browser or on a device (such as an iPhone with the github app) got to the home screen, click “repositories” on the left, click “landing,” click “code,” select “feed.xml” and edit by clicking the three dots (in the app) or the pencil (web browser) in the top-right. Now we can type away to our heart’s content to edit our xml file.

To get started, feel free to copy the format of the xml file for the Rykerr Medical Podcast. Here’s how it looks with just the first two episodes:

<?xml version="1.0" encoding="UTF-8" ?>
<rss version="2.0" xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd">
  <channel>
    <title>The Rykerr Medical Podcast</title>
    <link>https://rykerrmedical.github.io/landing/</link>
    <description>Rykerr Medical LLC is a platform for education focused on emergency, transport, and critical care medicine.</description>
    <language>en-us</language>
    <itunes:category text="Education"/>
    <itunes:image href="https://archive.org/download/submark1/submark1.jpeg"/>
    <itunes:explicit>false</itunes:explicit>
    <itunes:author>Rykerr Medical</itunes:author>
    <itunes:owner>
      <itunes:name>Rykerr Medical LLC</itunes:name>
      <itunes:email>ryan@rykerrmedical.com</itunes:email>
    </itunes:owner>

    <item>
      <title>Scripts Discussion with Richard</title>
      <description><![CDATA[
    In this episode we discuss the idea of creating scripts for learning protocols and refining procedures with Richard Templeman, a flight paramedic in Nevada.  We talk about the development of the idea, outline how we've used it personally, and provide examples of how you can do the same in your own clinical practice.  Let us know what you think and reach out with any questions.<br />
        <br />
        episode webpage: https://archive.org/details/scripts-discussion-with-richard_202502<br />
        <br />
        www.rykerrmedical.com to see what else is going on with the project
      ]]></description>
      <enclosure url="https://archive.org/download/scripts-discussion-with-richard_202502/Scripts_Discussion_with_Richard.mp3" type="audio/mpeg" length="31155456"/>
        <pubDate>Thu, 21 Jun 2021 12:00:00 +0000</pubDate>
      <itunes:author>Rykerr Medical</itunes:author>
      <itunes:image href="https://archive.org/download/scripts-discussion-with-richard_202502/Scripts_Discussion_with_Richard.jpg"/>
      <link>https://archive.org/details/scripts-discussion-with-richard_202502</link>
      <guid isPermaLink="true">https://archive.org/details/scripts-discussion-with-richard_202502</guid>
    </item>

    <item>
      <title>What is Up at Rykerr Medical?</title>
      <description><![CDATA[
        This episode is a short introduction to both the podcast and Rykerr Medical in general. Take a listen and let us know what you think!<br />
        <br />
        episode webpage: https://archive.org/details/what-is-up-at-rykerr-medical_202502<br />
        <br />
        www.rykerrmedical.com to see what else is going on with the project
      ]]></description>
      <enclosure url="https://archive.org/download/what-is-up-at-rykerr-medical_202502/What_is_Up_at_Rykerr_Medical.mp3" type="audio/mpeg" length="14586624"/>
      <pubDate>Wed, 2 Jun 2021 12:00:00 +0000</pubDate>
      <itunes:author>Rykerr Medical</itunes:author>
      <itunes:image href="https://archive.org/download/what-is-up-at-rykerr-medical_202502/What_is_Up_at_Rykerr_Medical.JPG"/>
      <link>https://archive.org/details/what-is-up-at-rykerr-medical_202502</link>
      <guid isPermaLink="true">https://archive.org/details/what-is-up-at-rykerr-medical_202502</guid>
    </item>
  </channel>
</rss>

And for future reference if this gets outdated or formatting requirements change or we figure out how to do it better, the URL is: https://rykerrmedical.github.io/landing/feed.xml. Just paste it into your web browser and you can see the current state of the thing.

Now that’s a bit complicated and includes lots of things that may be unfamiliar, but let’s create a hypothetical podcast and we’ll edit the xml file to reflect our new project. We’ll name the hypothetical podcast “The Hypothetical Podcast” and we, hypothetically of course, create our github account with the username HypotheticalCast.

The first bit of the xml file is the general information and the following sections are for each episode. If you’re curious about which each of the specific line items mean, please refer to both the video we made and our dear friend ChatGPT who seems to know a lot more about the technical specifics than we do. There are also many tutorials online that explain what each line item means. But let’s plug in pretend information into our file to create our hypothetical RSS feed:

<?xml version="1.0" encoding="UTF-8" ?>
<rss version="2.0" xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd">
  <channel>
    <title>The Hypothetical Podcast</title>
    <link>https://hypotheticalcast.github.io/landing/</link>
    <description>The Hypothetical Podcast isn’t even real!</description>
    <language>en-us</language>
    <itunes:category text="Education"/>
    <itunes:image href="https://archive.org/hypotheticalcastgraphic.jpeg"/>
    <itunes:explicit>false</itunes:explicit>
    <itunes:author>A Hypothetical Human</itunes:author>
    <itunes:owner>
      <itunes:name>The Hypothetical Podcast</itunes:name>
      <itunes:email>HypotheticalCast@gmail.com</itunes:email>
    </itunes:owner>

    <item>
      <title>What is Up at The Hypothetical Podcast</title>
      <description><![CDATA[
        This episode is a short introduction to The Hypothetical Podcast. Take a listen and let us know what you think!<br />
        <br />
        episode webpage: https://archive.org/details/hypothetical-podcast-1<br />
        <br />
        www.hypotheticalcast.com to see what else is going on with the project
      ]]></description>
      <enclosure url="https://archive.org/download/what-is-up-at-hypothetical-podcast/What_is_Up_at_Hypothetical_Podcast. mp3" type="audio/mpeg" length="14586624"/>
      <pubDate>Sat, 8 Mar 2025 12:00:00 +0000</pubDate>
      <itunes:author> A Hypothetical Human </itunes:author>
        <itunes:image href="https://archive.org/download/what-is-up-at-hypothetical-podcast/What_is_Up_at_Hypothetical_Podcast.JPG"/>
      <link>https://archive.org/details/what-is-up-at-hypothetical-podcast</link>
      <guid isPermaLink="true"> https://archive.org/details/what-is-up-at-hypothetical-podcast</guid>
    </item>
  </channel>
</rss>

So we just copy that into the xml file in github and “commit changes” to make it live. Next time we have a new episode, just copy everything from “” to “” and insert the specifics for the new episode of the podcast.

Note that not all of those fields/ lines are necessary. We could for sure simplify the xml file and RSS feed, this is just an example of how we have set ours up.

Next step is to verify the xml file to make sure it meets all the standard requirements. There are many websites and tools to do this, but the two we use are Cast Feed Validator and W3C. We just copy and paste the URL of our feed (https://hypotheticalcast.github.io/landing/feed.xml) into the tool and they each provide a report with any errors as well as suggestions to fix them. In learning this process, we came across many, many errors and not all of them were that simple or straightforward to fix. We leaned heavily on ChatGPT to troubleshoot specifics when the guidance from these validator tools wasn’t super clear.

One specific example that we show in the video and may not be easy to parse out from the reports provided by these RSS feed validators is the piece labeled “length” in the line that includes the URL to the audio file for the podcast:

<enclosure url="https://archive.org/download/what-is-up-at-hypothetical-podcast/What_is_Up_at_Hypothetical_Podcast. mp3" type="audio/mpeg" length="14586624"/>

This random bunch of numbers is actually the number of bytes in the mp3 file. If you get an example xml file for podcasts off the internet, the placeholder here is often 12345. But if we leave the length value as 12345 our podcast, in theory, could get cut off early when playing. That said, this is one of those grey areas in this whole process – we initially left it alone as 12345 and it worked just fine. We eventually worked out what the thing was and updated our xml file, but this may not be a necessary step. And to get this number, we need to know that 1 MB = 1,048,576 bytes.

So we have an xml file hosted via github to the interwebs. We also have files, the actual podcast content, hosted in a way on archive.org that allows the RSS feed to access them. And we validated our RSS feed and think we have it more or less ready to publish to the strangers of the world.

Last step in all of this is to get our RSS feed out there into the wild. This requires putting our RSS feed into some sort of system that normal folks use access podcasts. The two most common are Apple Podcasts and Spotify. Regardless of which one we use, we can still publish our podcast to both (and also other, less common hosts), so it doesn’t really matter. We’ve used both and they are both more or less the same. So go on over to either one, make an account, and use the custom RSS feed we created (instead of the one they would create). Details for that are omitted here since both Spotify and Apple have instructions and how-to docs on their websites. The podcast will then be live on the chosen platform and we can also choose to “distribute” to other hosts.

And that’s it. We now have a podcast hosted on both Spotify and Apple Podcast, just like all of the pros, but we maintain ownership of our RSS feed, have the content archived on the internet (hopefully) forever, and can freely decide where we want to host the thing. Happy podcasting!

Update Sep 2025: ConEd/ CEUs now available for this blog!

While not all prehospital folks place chest tubes, nearly all of us manage them after placement and in transport. There’s some variation in how these tubes are managed, especially when we consider austere settings, but only a handful of underlaying principles. The hope is that this quick primer will help clinicians feel a bit more at ease when transporting patients with chest tubes. Just know that some of the things we discuss here are contrary to how folks are typically taught. Be sure to practice per the rules and guidelines where you work and recognize that the following information is for educational purposes.

First, let’s just do a quick review of the thing. Chest tubes are placed into the pleural space when it is filled with stuff that shouldn’t be there. This might be air (pneumothorax), blood (hemothorax), a mix of both (hemo-pneumothorax), or other gunk entirely (pleural effusion or empyema). A chest tube is placed to help get whatever stuff is there and shouldn’t be out.

Stuff in the pleural space is problematic because it can impair breathing and exert pressure on the other things that live in the thoracic cavity. Both of which are problematic. Hopefully that’s a review, but if not the fine folks at Ninja Nerd have both a video and a podcast on the subjects of chest tubes and pneumothoraces, respectively:

Video: Ninja Nerd Nursing “Chest Tubes”

Podcast: Ninja Nerd “Pneumothorax”

Now not all cases of stuff in the pleural space warrant a chest tube. Sometimes we can fix the problem with a needle (needle decompression) or just by cutting into the space and venting it with a finger (finger thoracostomy) or by placing some other type of smaller-gauge pleural drain (pigtail or the like). No need to dive deeper for now, but look here for more information on those other techniques: LITFL “Own the Chest Tube”

The things that generally warrant a chest tube are those that cause hypoxia or threaten hemodynamic stability. In the transport setting these tend to be large pneumothoraces and/ or hemothoraces. They can be acute, as in a hemothorax caused by a ballistic injury to the chest, or may develop more slowly over time, as in a pneumothorax that evolves in a patient being mechanically ventilated with high pressures. In any event, we place a tube in the pleural space, get it secured, and then need to figure out how best to deal with the thing now that it’s in there.

There are two strategies we can use to manage a chest tube once it’s in place: application of suction or passive drainage. Let’s take a look at each, in turn.

Suction is generally applied after placement of a chest tube to facilitate re-inflation of a collapsed lung. Said another way, suction allows for the maintenance of a slight negative pressure in the pleural space (similar to physiologic normal or baseline) to help recruit alveoli that may have collapsed within the lung tissue itself. Suction can also facilitate the removal of fluid, as in the case of a hemothorax, although much of that drainage will happen passively. And lastly, suction is also used when there is a continuous leak of air from the airways or lung tissue into the pleural space (more on this idea shortly).

Now when we apply suction to a chest tube, we don’t typically do so by attaching the tube itself via suction tubing to a suction machine, rather we use a contraption that attenuates the suction to a specific goal (an atrium or similar device). If we look at the dial on our bedside or portable suction, the numbers are often in the range of 0-500mmHg with the optimal section notated in the neighborhood of 100-150mmHg.

But with a chest tube we often use 20cmH2O (which is about 15mmHg) and sometimes we go up to 40cmH2O (which is about 30mmHg). These pressures are much weaker than what we’d achieve with normal suction devices. This is important to note, because in the event that we don’t have an atrium on hand (which, as we mentioned, attenuates the pressure to a specific goal), we might be tempted to simply hook up the suction and let it suck all the bad stuff out. This is dangerous because we can injure lung tissue and cause further damage if we use excess suction. Also, it isn’t necessary because, as we already said, whatever fluid has accumulated in the pleural space will likely make its way out via the chest tube passively.

More on the subject of injury related to excessive pressure applied to a chest tube in this archaic 1997 paper from the Annals of Thoracic Surgery: “Thoracic Drainage”

Let’s recap this bit. We often see chest tubes with suction applied at 20-40cmH20 via a chest tube atrium. This low level of suction helps facilitate alveolar recruitment to re-inflate a collapsed lung. Suction should only be applied using an atrium or similar device, it should not take the form of our normal suction machine simply connected, in-line to the chest tube. And if we do we decide, against the aforementioned advice, to attach the chest tube to suction directly, be absolutely sure to keep it the number dialed way down.

So that’s suction. Easy enough. Let’s look at the passive drainage concept now. In this setup we simply allow whatever is in the pleural space to follow gravity and exit from the body via the chest tube. But there’s one extra step: we add in some sort of mechanism that allows stuff out but prevents air from getting back in - a one-way valve.

We need a one-way valve in the system because if we allow air to go back into the pleural space via the chest tube, which will happen every time a spontaneously breathing patient takes a negative-pressure breath, we basically create a sucking chest wound. Which we would all agree is counter to what we are trying to do for our patient.

One-way valves in chest tube systems can take either of two forms. The first is a mechanical one-way valve that we add to the end of the chest tube:

That photo is from an article titled “Heimlich Valve and Pneumothorax” that provides quite a bit of detail on the little device and how to use it.

A one-way valve can also be improvised with a glove or a bag:

For a text-based explanation and the above photo, read: “Improvised Chest Tube Valve for Intra-Hospital Transport”

And this second example which shows how we might do the thing with a glove and a rubber band is from the show notes of an episode of The Dustoff Medic podcast which, sadly, is no longer available: “Tube Thoracostomy (Part 2)”

The other way to do this one-way valve thing is to use a water seal. To make this happen, we simply run tubing from the chest tube into a container of water or saline. As the patient exhales, air that might be in the pleural space escapes from the chest tube via the tubing and it travel up through the fluid into the atmosphere. Then as the patient inhales, the water prevents air from being sucked back into the tubing via the chest tube. A simple setup of this looks like so:

It’s also worth noting that in both systems, either the mechanical valve or a water seal, fluid can also escape. This movement of fluid, however, is largely dependent on gravity, so be sure to keep the system below the level of where the chest tube enters the body. This also prevents whatever has drained into the collection chamber from accidentally making its way back into the pleural space if the container is too full and tips.

Recap number two. Chest tubes can either be placed to suction or be allowed to drain passively. If draining passively, there needs to be some sort of one-way valve in the system to prevent air from traveling the wrong way back into the pleural space. This one-way can be either a mechanical valve or a water seal.

In practice in the modern healthcare system, we pretty much always use an atrium system. This was noted above when we explained that the atrium allows us, among other things, to dial down or attenuate the suction to a specific goal. The atrium serves as a collecting vessel (so we can measure output), a water seal, and a suction device - all in one! Here is a labeled example of one such device:

The above image and the next one are borrowed from Deranged Physiology. For links to pages that have all you need to know about setting up these types of devices, look at the references section at the bottom of their writeup: “Underwater Chest Drain System”

We can also improvise this setup with buckets and tubing we likely have laying around:

Note that the water level in which the tubing is submerged in the third (right-most) bottle correlates to suction applied, regardless of what the suction device or machine is set to. A 10cm column of water means we end up with 10cmH2O (8ish mmHg) of negative pressure in the system.

And then final thing on this whole process is that the typical strategy after placement of the chest tube starts with application of suction, transition to water seal, then removal of the tube. Sometimes there is an intermediate step of clamping the tube for a certain amount of time in between the water seal and removal steps - this allows us to see if a pneumothorax re-develops. If it does, simply unclamp and consider reapplying suction.

To read more on this idea: Clamping of Thoracostomy Tubes: A Heretical Notion?

And then the transition to water seal step happens when we think the lung has re-inflated and there is no longer air in the pleural space. We make this determination based on imaging (CXR, not POCUS since lung sliding may not return for many days) and/ or resolution of an air leak and cessation of tidaling. For a review of these concepts (air leak and tidaling), as well as bedside management of chest tube in the hospital setting, listen to this excellent podcast overview: Straight Nursing Podcast “Build Your Confidence Working with Chest Tubes”

And here’s a one-page cheat sheet to summarize or review those things: ICU One-Pager “Chest Tubes”

As a quick side note: there are many places around the world that don’t use suction at all and simply manage chest tubes by water seal alone. It’s just that the lung re-inflates slower without the extra assistance of applied suction. We showed one example already, but here’s another:

Next let’s talk about problems that can happen along the way. Problems basically come in two flavors - either the system is broken open in some way or it inadvertently gets occluded. There are also issues related to increases and decreases in output, but that’s a bit beyond the scope of this discussion. Suffice it to say we should receive in our patient report or handoff what is to be expected, in terms of output, and what it might indicate if we are significantly above or below that goal.

Back to the two main issues: disconnection and obstruction. It’s worth mentioning that there is a bit of a difference in what can go wrong based on whether the patient is spontaneously breathing or mechanically ventilated. As we already discussed, spontaneous ventilation occurs via a negative pressure mechanism. Contraction of the diaphragm and expansion of the chest wall cause an increase in intrathoracic space, a decrease in pressure, and movement of air into the lungs. If there is a hole in the chest, either a sucking chest wound caused by an injury or a tube put in place by a clinician, this can result in a pneumothorax that can then tension as more air is sucked into the pleural space with each breath exacerbating the pathophysiologic process. This is why the one-way system is important.

In the mechanically ventilated patient, the situation is a bit different. Imagine the following: totally normal and healthy patient with a chest tube in place, the tube goes from the outside world through the chest wall into the pleural space, the patient is paralyzed and ventilated with positive-pressure ventilation, the chest tube is unclamped and not connected to any sort of drainage or one-way system. In this hypothetical situation, the risk if a pneumothorax developing is quite low, as any air that may make its way via the chest tube into the pleural space on exhalation will be pushed back out with inhalation when a positive-pressure breath is given and the lungs expand.

That said, this situation rarely happens. More often a chest tube is placed in response to some sort of trauma that penetrates deeper than the pleural space and its linings and goes into the lung tissue itself. In these sorts of injuries air can get into the pleural space as we deliver positive-pressure breaths from the airways themselves - air simply escapes from the site of injury at the lung tissue and gets into the pleural space from the inside. A chest tube gives that air in the pleural space a place to escape to, so long as it is patent and open. Think of it as pneumothorax occurring from the inside out rather than the outside in:

Versus how we often think of it (shown below). And this how we think of it situation may be specific to EMS because we seem to focus a lot on traumatic injuries and chest seals and the like.

This idea of a continuum between pneumothorax and bronchopleural fistula is mentioned here, along with a general overview of the ICU management of both issues: IBCC Chapter on “Pneumothorax and Bronchopleural Fistula (BPF)”

In the inside out pneumothorax situation, a kink in the tube or clamping it intentionally would inhibit this escape of air. This problem is amplified if the patient is being ventilated mechanically or via positive pressure, as we are pushing air out of that injury site with each breath. For that reason, we often advise clinicians not to clamp chest tubes. This general stance against chest tube clamping is very common in many places.

In other places, however, it is common practice to clamp the tube during transitions. This might be while moving a patient from a bed to a stretcher, while in CT scan, while getting out of bed, etc. The reason for this is that there are also risks of a disconnect occurring in the system. For example, maybe the tubing to the atrium gets snagged and pulls off. In the spontaneously breathing patient, as we talked about earlier, this could result in a new or worsening pneumothorax. In the mechanically ventilated patient, however, clamping itself may pose a greater risk.

One way to conceptualize this is by way of a matrix. Clamping and disconnection have different likelihoods of poor outcome (i.e., a pneumothorax, new or worsening) depending on whether the patient is breathing spontaneously or mechanically ventilated:

There’s also a time component, as these risks of complication decrease with resolution of the pneumothorax:

If we agree on these two matrices, which may actually be up for interpretation (and do reach out with thoughts on this!), the only risky scenario that is consistently risky would be spontaneously breathing patient with an accidental disconnect. So we could make the case to clamp the chest tube for spontaneously breathing patients and then either apply that rule across the board or have an alternate “leave unclamped” rule for vented patients.

In practice, however, it probably makes the most sense to leave the system intact and unclamped but have clamps or hemostats on hand to troubleshoot if needed. This idea of having all the things needed to troubleshoot a chest tube issue is mentioned in this open-source textbook chapter: Clinical Procedures for Safer Patient Care “Chest Tube Drainage Systems”

This decision, however, could arguably vary depending on what sort of system we have attached to the tube. If we are using a simple water seal of the variety that is just a bottle with tubing partially submerged, we may opt to clamp the thing to avoid fluid spilling back from the bottle into the tubing and into the pleural space as the patient is packaged. Especially if the patient needs to be carried or the maneuvered into any position other than supine.

In the scenario shown below, a patient has been packaged for transport with a water seal system placed between his legs. There is a risk that the bucket could spill or tip and that fluid could make its way back into the pleural space. Or even that the distal end of the suction tube gets released to air and therefore the water seal is broken. For this reason, some may advocate to clamp the tube during movement.

And then what about suction? Totally AOK to stop suction, transition to water seal, then reattach to suction later on. Suction is used to facilitate re-inflation, but stopping or pausing it doesn’t mean that the lung will automatically deflate again. The water seal is our one-way valve to keep things stable and maintain progress until we get suction up and running again.

One caveat here is that in cases where there is significant leak of air from the lung tissue itself or the lower airways, similar to a bronchopleural fistula, cessation of suction can make a pneumothorax worse. In these cases, be sure to keep any interruption in suction to the absolute minimum needed to do whatever it is we need to do. It probably isn’t ever necessary, except in rare cases, to maintain suction with a portable machine during movements, just focus instead on being efficient.

Now on to troubleshooting!

First rule is to try not to dislodge the tube. Seems obvious enough. In general, these tubes are fairly well secured with sutures, but we know how these things can happen. And if you have a tube that doesn’t seem secure, make it so.

Video demonstration of one technique that can be used to secure a chest tube with towel clamps (i.e., if no sutures are available or if the sutures have failed somehow): “Towel Clamp Temporary Chest Tube Securing Method”

And here’s a screenshot of the procedure halfway through that shows one of two clamps in place to give the gist of the thing:

We could also use copious amount of whatever super-sticky tape happens to be on hand, so long as we keep the tube in place and don’t inhibit normal chest wall movement in the process.

Worst case with pulling the tube out completely is that we cause another one of those sucking chest wound scenarios and have to apply a seal as we would in any other setting with that sort of injury. We are more likely to need a chest seal the further away in time we are from initial placement. For example, if we put a hole through the chest wall and then let it go immediately, as in performing a finger thoracostomy, the hole will likely get sealed up as the tissue of the chest wall falls back in to place. But if we stick a tube in the space for a week or two, some healing takes place, and we are more likely to have a hole remaining when the tube is removed. For this reason, some folks say to not worry about an occlusive dressing after finger thoracostomy, but it is generally expected and encouraged with chest tube removal.

This idea is discussed in passing here: Foamfrat Podcast “Finger Thoracostomy w/ Dr. Cynthia Griffin”

In any case, let’s try not to dislodge the chest tube. And if it does get removed accidentally, go ahead and place an occlusive dressing for good measure and monitor for the need to decompress or vent just as we would with any other use of an occlusive dressing to the chest.

For a thorough discussion on chest seals, consider listening to this episode of The EURMED Podcast: “To Chest Seal or Not to Chest Seal”

If the tube dislodges only partly, we need to determine if it’s still useful or not. There are a few ways to do this. If we have a water seal in place that is also to suction, worsening or new bubbling indicates a leak (i.e., the system is no longer useful or not as useful as it was before). If we are to water seal only, we can attach to suction as a diagnostic tool. This involves clamping the tube and seeing if the leak resolves. If we clamp at the chest tube itself and the leak resolves, we know the issue is in the lungs or in the tube itself; if the leak persists, the leak is somewhere downstream. This concept of clamping to diagnose a leak is discussed in the Straight Nursing Podcast “Build Your Confidence Working with Chest Tubes” which we have mentioned already.

If we have a chest tube to an improvised water seal or to a one-way valve in which we can’t apply suction, we may be able to hear or feel a leak instead. We can also look at the thing directly, which will require taking the dressing down to visualize where the tube enters the skin, and see if it’s still where it should be - if we see holes (aka fenestrations), then we have a problem.

Image showing fenestrations in chest tubes borrowed from “Managing Chest Tubes: Air Leaks and Unplanned Removal”

There is the case that no fenestrations protrude outside of the body, but rather rest in the chest wall tissue itself. In this case we may see new or worsening subcutaneous emphysema. Be sure to do the normal patient assessment things and get professional hands on the patient’s body to look for this sort of thing.

If we have a dislodgment and are sure it’s not a leak elsewhere in the system (because we clamped the tube itself and saw the leak go away or because we took the dressing down and got eyes on the insertion site and saw fenestrations showing or found evidence of new subcutaneous air, all as mentioned above), there are a few options that may come to mind: re-insert the tube, seal the holes, remove the tube.

Typically, only one of these options, remove the tube, is endorsed for a partially dislodged tube, but let’s work through the other options just for good measure to explore why that is the case.

Reinsertion of the same tube is generally discouraged due to concerns for sterility. This take, however, is based on the assumption that we have the capability to repeat the procedure at a new site on the chest wall in a safe and clean manner. That assumption may not always be true. For this reason, re-insertion or repositioning of a displaced tube may need to be considered if the tube is for sure needed and there is no possibility of placing a new one or decompressing the pleural space by some other means.

Alternatively, we could, theoretically, leave the thing as is and cover with a chest seal or air-tight tape or occlusive dressing - basically try to reseal the device and hope that the tip of the tube remains in the pleural space. We aren’t actually aware of any case studies or documentation of salvaging a chest tube in this way by using a chest seal or the like, but if anyone out there has anything on the idea get in touch and we’ll look into it. It seems unlikely and would generally be discouraged, as we’d likely end up with lots of subcutaneous air - if we can see holes or fenestrations outside the body, there are more on the inside and they may track into the tissue of the chest wall. So resealing a partially dislodged tube is probably not a good idea. And this would matter more (as in be a more significant problem) with a mechanically ventilated patient.

And if we do decide to reinsert or salvage a partially dislodged chest tube that was previously to water seal, it may make sense to apply suction once we get the thing working again. Applying suction alone will not fix the problem of a dislodged tube with a leak but can help mitigate the development of a pneumothorax or the spread of subcutaneous emphysema after the primary fix is in place.

Chest tube removal, our other option, is the pathway that is generally recommended. Again, this assumes our ability to place a new tube if needed, so if that isn’t the case, we may need to explore alternatives. Chest tube removal is typically done with a bit of forethought and while having the patient hold their breath or while performing an inspiratory pause if ventilated. In the case of a partially dislodged tube in which air may have already made its way into the pleural space, it could theoretically help to do these things as soon as the issue is identified, but probably not a big deal if we don’t recall this step in the moment. The bigger deal would be leaving the air leak in place and allowing even more air to get inside and worsen the pneumothorax. Note that this one matters more with the spontaneously breathing patient.

Video demonstration of a simulated chest tube removal: HealthPartnersMedEd “Chest Tube Removal”

If the chest tube remains in place and has not dislodged, rather it is simply the case that the tubing extending from it has disconnected somehow, this too can also cause problems.

For the spontaneously breathing patient, this situation can cause the development of a pneumothorax. First step, then, is to clamp the tube to prevent that pneumothorax from developing, then get your system and one-way valve back in action. For the ventilated patient the need to clamp the thing right away may be less important, so just get the system set back up.

If there are time and resources, recall that this circuit of atrium, tubing, chest tube runs inside the patient’s body. This means that a break in the system and tubing dragging across the clinic or ambulance floor puts the patient at risk for infection. One more reason to always try and keep the system intact. Also consider swapping tubing if indicated or cleaning contaminated components.

Now it may have become apparent that there’s a bit of nuance to this discussion depending on whether the patient is ventilated or not. If we can remember those specifics, great. If not, fine. We can also manage chest tube issues with a systematic process that is the same regardless of what is going on with the patient. The reason we can do this, despite all the differences discussed, is that all of the bad outcome scenarios take time to develop. So if we have a system in place to correct an issue in a timely manner, it doesn’t really impact the patient in an adverse way overall.

Let’s play it out step by step to make this idea clear. Imagine we are loading a patient with a chest tube into our ambulance or aircraft. The chest tube snags on something, gets tugged, and the tubing to the atrium disconnects. Clamp the tube, reconnect to the atrium, and reassess. Specifically, reassess to make sure the chest tube is still in place and working as intended.

Even if this patient is mechanically ventilated early in the course of a penetrating chest injury and we know for sure that there is a risk for worsening a pneumothorax with a clamped chest tube, it’s fine to have the thing clamped for a few moments while we fix the system. Just don’t forget to unclamp it as soon as you can.

And what if during this shuffle we drop the atrium and it breaks and now we’ve lost our water seal? No big deal. Clamp the tube and make a new one-way valve. Use a commercial device, improvise one with a glove and tape, or reattach tubing to the end of the chest tube and submerge the other end in some sort of sterile fluid. And then once that’s done, unclamp the tube and reassess.

The idea here is that while it may be fun and nerdy to discuss the nuances and it’s worth knowing the “why” behind these things, in reality when there’s a problem to be solved, we need a simple, actionable plan that can be utilized in all situations without having to think too hard.

One final subject: accidental occlusion in the system. We’ve covered already why it can be problematic to clamp the system in different scenarios, but let’s consider what to do if this happens unintentionally. First is to identify the problem. Indications could include loss of tidaling and/ or bubbling, decrease in output, and/ or development of a pneumothorax (and therefore any of the associated signs and symptoms that go with that).

Obviously, it’s fine and encouraged to remove a physical obstruction if the chest tube or tubing got pinched somehow from the outside. For internal obstructions, such as a clot of blood or tissue, there are some considerations. First is that most of these blockages will resolve without intervention or with suction (low and continuous, as described previously). If we are worried, it is OK to roll the tube or tubing between the fingers to try and break up a clot, but stripping the tube is problematic because that can generate significant negative pressure which (as discussed way earlier) can cause injury or further complication. If we’re just to water seal and have a presumed clot, apply to suction, and give it time.

There are some other interventions that we can employ to make a clotted chest tube patent again, but these are not often utilized for tubes placed in the pleural space. This is because we can generally fix the complication of an occluded tube if it does occur (i.e., decompress a pneumothorax) and also because many cases of clotted chest tubes resolve on their own.

If there is a blockage that results in the worsening of a pneumothorax with signs of tension and we can’t get the chest tube or the system cleared, treat as any other pneumothorax with needle decompression, finger thoracostomy, or placement of a new tube. We don’t need to take the occluded chest tube out in the moment, as this can be deferred until later or it may even clear with time.

More on all of this and other fun things here: “Thoracostomy Tubes: A Comprehensive Review of Complications and Related Topics”

And actual very last thing is what to use to clamp the tube. Whatever is on hand. Some atriums have little plastic slider clamps that can be used along the tubing itself:

You can also pinch the tube or tubing with fingers, fold it over on itself and tape it, use clamps, etc. Doesn’t much matter which type of clamp, but if we have access to big ones with no teeth, that’d be preferred. And if not, even the small ones with teeth work just fine. Chest tubes and suction tubing are thick and fairly difficult to chew apart. The more important thing is to work through troubleshooting systematically and remove the clamp once the system is working again as it should.

Let’s summarize all of this and then we’ll call it a day.

Chest tubes are used to fix issues caused by unwanted stuff in the pleural space. At a minimum, chest tubes drain passively with a one-way valve system in place. We may also apply a low level of suction to facilitate lung re-inflation.

Clamping the chest tube is fine for short periods of time and some people and places do that routinely during transitions or movement of the patient. That said, many places advocate to avoid clamping unless necessary and to focus, instead, on safe movement practices and not breaking the system in the first place. As for suction, it’s OK to discontinue during transitions and then reapply afterwards.

Troubleshooting emergencies is largely dependent on having the stuff you might need on hand or close by and approaching issues in a systematic manner. Breaks in the system, accidental dislodgment/ removal and inadvertent occlusion can all be identified and treated quickly to prevent acute deterioration in patient status.

Here’s a simple graphic that may help conceptualize what’s going on in the body when we discuss hemodynamics and different patterns associated with certain pathologies:

In reality, its often a rough sketch in the margin of a piece of paper, but that’s the beauty of the thing – it’s a simple-to-draw framework for solving clinical problems:

The basic idea is that we can visualize movement of blood through the heart, body and lungs. We start with what is normal:

From there, we can then add in complications or disruptions to this flow to represent different pathologic processes. For example, let’s consider mitral valve stenosis. First a review of the normal thing:

And then we make that mitral valve stenotic (which decreases efficacy of movement across that valve) and adjust things as so:

Early in the process we see blood flow back up into pulmonary circulation like so:

And then with time we see issues on the right side of the heart also:

This sort of exercise is particularly useful in testing scenarios where hemodynamic values or certain conditions are presented and we must decide what findings are most likely. For example:

Just have the normal ranges memorized or, better yet, have a reference card of some sort readily accessible. Here’s a quick video of working through these questions one by one:

Next point of conversation: what to do with all this academic nonsense in clinical practice. We often have to work with incomplete batches of information and/ or verify that the numbers we have on hand are actually worth accepting as true (and therefore accurate descriptors of patient status). Take, for example, this recent case we had.

Adult male patient, myocardial infarction with Impella placement in cath lab after going into cardiogenic shock on the table. He’s got the Impella in running at P9 or max flow. There’s a single-lumen Cordis at the right internal jugular (IJ) and a pulmonary artery catheter (PAC) in the groin, plus one peripheral line. He’s hypotensive on arrival, as seen on both non-invasive or auto-cuff and the Impella screen (there’s no other arterial line in place), so we give a bolus and start an Epinephrine drip. He’s also got heparin running for anticoagulation, so we keep that going as well. And then we do push-dose sedation and analgesia as needed. Blood pressure/ mean arterial pressure (MAP) responds to initial interventions, so we proceed with things.

Now here’s where troubleshooting and considering all these hemodynamic numbers comes in to play. The only data point we have at the moment is a BP or a MAP, which roughly correlates to cardiac output so long as heart rate is reasonable and constant. And that’s OK for now, but not a ton of information to be gleaned there. We transduce the PAC for both a pulmonary artery pressure (PAP) and also to make sure we don’t inadvertently wedge en route – the PAP sheds a bit more light on the thing. Consider whether it’s high or low and how that might look in our sketch:

And then the next data point we could potentially get is a CVP. We could do that either at the Cordis in the right IJ or and the proximal port on the PAC. While we’re at it, let’s review all of our access and what we can do at each of the various places:

But assuming we do transduce one of the lines for a CVP and have that number available, here’s how the decision matrix of sketches might look:

Now let’s say our PAP is high (which it was in the case presented). Of that list of things on the high PAP side of the matrix there’s only so many things to do in transport, regardless of whether CVP is up or down. We’re probably not going to diurese in flight or give inhaled nitro (but power to the people who do!), we can assess for tamponade and rule that out, we can optimize cardiac function with things like dobutamine or electrolyte replacement (i.e., calcium), and then we can give volume.

The CVP tells us what the preload is and guides the decision of whether we should give fluids or not. But there are other ways to get this piece of information – fluid responsiveness, just waiting for a suction alarm on the Impella and treating reactively, or if you work in the modern age of medicine, get an ultrasound probe on the patient and assess for fluid status that way. This is all to say that we don’t actually need the CVP and can maybe save the headache of transducing a second line in transport to focus on other things.

Another framework for thinking about this would be to do a mental inventory of the interventions on hand and decision points for each. Here’s what a working list might look like:

• Fluids – suction alarm, low CVP, fluid responsiveness, or collapsed IVC on ultrasound
• Increase epi drip – low MAP
• Start dobutamine – refractory low MAP after epi increase, narrowing pulse pressure, evidence of pulmonary edema
• Consider other pressors – MAP approaching 50 despite all of the above
• Consider ACLS stuff – super low MAP sustained less than 50

Now that’s a complicated cardiac device case and we recognize that those are super rare and don’t come around all that often, so how about a more likely scenario. Adult patient with pneumonia turned sepsis and ARDS being transferred for higher level of care. Ventilation is trash, we’re acidotic, require high PEEP, are on multiple pressors, quite tachycardic, and the BP drops whenever we give sedation or analgesia. Let’s see it all sketched out:

And then working to fill in the gaps, here’s what we might see in terms of all those other hemodynamic parameters, plus actions to be taken:

alternate link to open that gif in another window, just in case it’s tough to see

Big takeaway from all of this: draw pictures, it helps. Other less important lessons: knowing how different pathologic events affect the flow of blood through the body can help direct interventions, knowing how we can gather specific pieces of information in different ways can help with this process, and piecing together an overall clinical picture with an incomplete set of data points takes practice.

Very last thing that also serves as a public service announcement: if we are transducing lines in transport (as we should any time we have a PAC in place), be sure to review the basics. This is especially true for those of us in the transport setting that don’t do this sort of thing often. Know which ports on which lines get transduced for which pieces of information, do all the normal setup things (inflate your fluid bag, level the transducer where you want it, flush the thing, etc. and reassess along the way), and then after all of that draw the fun pictures and put it together into a clinical pattern.

And there you have it. Next time you come across a tricky question on a test or a complicated clinical case, consider using this sort of graphic to help work through and visualize the changes or expected findings associated with a given pathology.

Personal notes:

Cannot for the life of me recall where I first came across this idea of using graphics like this to work through these types of problems, but I know for sure I didn’t invent the thing…

The photo of test questions is from a recent competency I had to take on the ICU where I work part time. Had to wait until after we released those keys to post this, just in case there were any outstanding tests to be completed (not that any of the folks I work with know I have a blog or will read this…). Also wanted to make sure the answer key matched what I got. It did :) But those questions gave me the idea to write this.

The Impella case came up while I had this drafted, decided to add that and the other case to give some clinical context. Good stroke of luck I think.

And it may seem that I have all this information in my working memory in real time. Not the case. I have the advantage of both hindsight and meticulous notes/ reference materials I’ve made over the years to help with this sort of thing. I use them all of the time and you should too.

Also thanks to Scooby over at SFCEBM for chatting about the initial draft of this. Specifically about reiterating the point that we should always transduce a PAC to monitor for inadvertent wedging and that the introducer for the PAC probably has another line/ point of access for meds – this second bit was something I missed on this transport.

As always and forever, let us know if you’ve got any feedback on the thing.

Reference:

J Larry Jameson. (2020). Harrison’s Manual of Medicine. Mcgraw-Hill Education.

This is a repost of one of the chapters in our free book on mechanical ventilation in transport. Fore more on that or to read the whole thing, take a look at out website: www.rykerrmedical.com/clinical-resources/vent-management

Update July 2025: Also note that there is a newer version of the vent book in the works which will include a rewrite/ update of this chapter. To view that in real time, take a look here: Vent Book v2 on Google Docs

The next thing to chat about is what to do if the patient begins to decompensate while on the vent. Let’s start with a common memory tool to address some of the major causes of acute deterioration of the mechanically ventilated patient:

There are also some variations of this guy, so we may see it out there with an “S” at the end for stacking (i.e. AutoPEEP), an “R” at the end for rigidity of the chest wall (a rare complication of Fentanyl administration), or even with the “P” to represent pain and/ or (Auto)PEEP. It is also sometimes accompanied by another mnemonic called DOTTS which outlines actions that can be taken to fix issues identified by DOPE. Now DOTTS includes a step where we bag the patient with a bag-valve mask (BVM) and we’ve crossed that step out. We don’t recommend routinely taking someone off the vent unless we have good reason to and we’ll get back to this idea in just a little bit. But just so we can see it in its true representation, here it is:

The DOPE mnemonic (with or without DOTTS) is easy to remember and can be used to guide the initial troubleshooting process when the patient starts to deteriorate. Many of these occurrences can be tied to Alarms or other assessment parameters, but that depends on which type of machine we are working on and what tools we have available. For example, a tube displaced too deep will give a high-pressure alarm (and eventually a low minute volume alarm) and a tube displaced out of the airway will likely result in a low-pressure alarm. In regard to other assessments: a tube displaced too deep will lead to a high Mean Airway Pressure or Peak Inspiratory Pressure, low exhaled tidal volume, patient discomfort, etc. and a tube displaced out of the airway causes a low mean airway pressure, drop in EtCO2 with change in waveform, hypoxia, etc.

Because there are so many things to consider, building an algorithm to troubleshoot each possibility gets a bit difficult. We’ll go ahead and do it anyway, we just need to consider a few more things in preparation. First of all is that acute deterioration of the vented patient doesn’t always mean that there is an issue with the vent, it could be some other issue beyond the vent (i.e. endotracheal tube displaced or pathophysiologic process). If it’s a vent thing, then we mess around with the vent; but if it’s another issue, our interventions should focus on drugs and procedures and that sort of thing. Think of it this way:

Now the reality is that it isn’t always so cut and dry. There are times where we do both vents things and other things simultaneously. An example of this would be a patient already on the vent who experiences an allergic reaction to something. In this case we could simultaneously proceed with an Obstruction vent strategy and give drugs to fix the problem. So while our little algorithm may be too simple, it often helps to take a moment to think about which sort of problem we have on hand and act accordingly.

In light of the fact that there are so many variables involved, here’s the stepwise approach we suggest for troubleshooting acute deterioration of a ventilated patient. This approach takes advantage of feedback that we may have available to us from vent alarms and assessment parameters:

And in fact, one could argue that “use alarms to guide treatment” may even be a quicker solve than starting with the ABCs. While we recognize that this is blasphemy in the world of EMS and transport medicine, here’s how that might look:

By working through each of these steps systematically, we hit all of the DOPE things and identify where in the system the issue lies (vent, equipment, physiology). Now, it gets a bit more complicated when we add in specifics for each step along the way, but remember that the basic idea is a simple set of four steps:

A few things to note about this algorithm: with a partially deflated cuff, remove air from the cuff and then re-inflate with an appropriate amount of air. Simply adding volume can contribute to both injury from over-inflation and likelihood of tube displacement. Also consider using a monometer to measure cuff pressure and establish a baseline moving forward if available. And if the cuff is defective, consider utilizing a bougie to exchange it for a new one or take steps to fix the issue temporarily.

There’s no way to accommodate all possibilities in a single algorithm without getting too crazy on the details, but that’s the basic idea. Before moving on, just a few things to note. First is that a low minute volume alarm may also accompany acute deterioration, but it will likely be tied to either a high-pressure alarm (with breaths cycling off due to that alarm getting triggered) or some kind of disconnect (which would likely be indicated by a circuit disconnect or low peak-pressure alarm). We also didn’t include a low-frequency or low-PEEP alarm anywhere in this flowchart, as those probably aren’t tied to an acute deterioration unless accompanied by one of these other trump cards. And then we already showed this before (and recognize that not all of these are acute life threats), but just to clarify again the different lung and airway issues we might come across:

Now let’s summarize what actions to take in the event of an acutely deteriorating patient on the vent. While there is a well-known memory tool (the DOPE mnemonic) to guide us through troubleshooting potential issues, that tool doesn’t consider feedback from the machine (i.e. alarms) and, therefore, we suggest a simple sequence of four steps to work through it all: check the ABCs, look at and address any alarms, review the Three Big Things, then check pressures. If by then we haven’t figured out our problem, we can consider taking the patient off the vent and bagging by hand (still not a great strategy though…) or getting out the ultrasound machine to try and identify an issue (if available).

The final idea here is what to do if the patient goes into cardiac arrest while on the vent. Standard practice in this situation is to take the patient off the vent and have someone ventilate by hand while CPR is initiated. That may be a valid option if we have extra hands, but in transport with only two clinicians it may not be possible. If our particular machine allows us to ventilate without patient triggers (i.e. in controlled mechanical ventilation or intermittent mandatory ventilation), that would be the preferred approach. If not, then we may be able to approximate those Basic Modes of Ventilation by maxing out the sensitivity of our trigger. The reason we turn off the mechanism for patient-triggered breaths is that the machine will likely be triggered to deliver a breath with each chest compression given.

Another consideration in this cardiac arrest situation is that we may need to increase our high-pressure limit so that breaths don’t get cut short early during this time. If the machine is trying to give a breath while we are trying to simultaneously give compressions, we will most definitely exceed a normally-set high-pressure limit with the result that breaths will get cycled off. Ideally we could time our compressions with the machine’s breaths to avoid this, but that would be difficult to accomplish. Increasing the high-pressure limit does predispose the patient to both barotrauma and increased intrathoracic pressure, but it may be the best course of action when working a code with limited resources.

One last recap and then we’ll move on. With a deteriorating patient on the vent, try to keep it simple and work through four steps: ABCs, alarms, Three Big Things, and pressures. If after that you can’t figure out the issue, consider removing the patient from the vent and bagging by hand (with a PEEP valve, if available). And if other assessment techniques such as ultrasound are available, they can also be used to further investigate causes of deterioration. In the event that the patient arrests while on the vent, cancel out patient-triggers and increase your high-pressure limit.

Helping out overseas as an EMS person is an idea that appeals to many of us. The draw includes both a feeling of satisfaction with giving back and the excitement of something new. The challenge, however, is finding opportunities that are relevant to the EMS clinician and that match well with what we are looking to get out of the experience. So that’s what we’re going to discuss – how the EMS provider gets into this scene and how he or she finds opportunities that both offer value and that match our unique skill set.

Medical volunteerism, as the general field is known, is mostly designed with the non-EMS clinician in mind. Opportunities abound for physicians and nurses and many others in between, but not so much for medics and EMTs. Of those opportunities that are available to EMS providers, most preferentially recruit ALS folks, due to capabilities and scope of practice. This makes it a bit difficult for EMTs to get in on things, but it’s still possible, and we’ll discuss some specific opportunities in just a moment. The general idea here is that it can be tough to find opportunities and the search may require a bit of both persistence and patience.

Another consideration is that the work itself may be quite different from the normal day to day grind of an EMS service. While there are ways to volunteer running calls on a truck and responding to emergencies, these opportunities are quite rare. More often than not the focus is on primary care or education. If these are unfamiliar, it can be intimidating for the EMS provider to step into this new space. And while that’s completely understandable, it is definitely manageable, as long as the overseeing organization provides support and guidance to help navigate that gap in experience. This brings us to our next topic of discussion: choosing the right group.

Just as not all EMS agencies are the same, in terms of support offered to providers and quality of care delivered in the field, neither are NGOs (non-governmental organizations) and charities that recruit medical volunteers. Some are great and some aren’t. An NGO may offer different projects or opportunities, some of which are great, and some of which aren’t. It can feel a bit overwhelming to try and sift through the many options, but that’s what we’re here to help with. One way to work through this process of finding an opportunity is to consider a few questions: What are we looking for? What sort of experience does the group have with EMS clinicians? What are the hurdles involved? We’ll talk about each of these in turn.

The first consideration is to reflect on what we hope to get out of the experience. If it’s exposure to something new and different, many opportunities may fit the bill. If, however, the goal is clinical exposure in the EMS field, that may be more difficult to come by. Other motivating factors might be to practice or learn a specific language, to use the opportunity as a gateway to a specific part of the world we’ve always wanted to visit, or simply to try something new and get out of our comfort zone a bit. Whatever the case may be, have those goals in mind and be sure to make sure the experience aligns with them.

Next is to look into what history a group or organization has with other EMS volunteers. This isn’t to say that an absence of such history means an opportunity isn’t worth pursuing, rather a question to clarify whether or not a path for someone in our role has been established or not. If so, we can easily determine whether we like that path and want to keep moving forward with it. If not, however, we may have to establish the path via a dialogue with the organization about scope of practice and skill set, legal considerations, and/or personal comfort in working outside of the traditional EMS arena. And then if we like a given path, whether forged by others in the past or in the makings via our own effort, we can carry that conversation forward.

Sidenote on this idea: EMS practice and the associated labels for healthcare providers vary widely around the world, so keep in mind that not all opportunities for “medics” apply to US-certified paramedics or EMTs. Likewise, not all international organizations will be familiar with details regarding scope of practice for various levels of providers. These sorts of things are a bit easier to navigate if a given group has experience working with EMS providers (from the US or other countries), but that shouldn’t be considered a prerequisite – just ask clarifying questions and make sure that expectations are clear ahead of time.

The last thing on our short list of questions when considering volunteer opportunities is what steps are involved in getting on board with a group. Many outfits require an application and/or online training, but those sorts of things tend to be fairly manageable. Other obstacles, which may be more difficult to navigate, include immunizations, prophylactic medications (mainly against malaria), visas, etc. The big hold up for many of these pursuits is money. It’s not uncommon for organizations to charge a fee to volunteer with them, plus it’s expensive to travel to many of the places where these groups work. That may or may not be a gamechanger, but it’s good to know up front what expenses to expect from something like this so that we can make a well-informed decision on it all.

As an example, let’s work through these considerations for an organization with which we have extensive experience. Global Response Management (GRM) is a non-profit that provides medical care around the world. They started in Mosul, Iraq in 2014 treating trauma casualties as other organizations pulled out of the region due to safety concerns. They currently have ongoing projects in Mexico along both the US and Guatemalan borders and actively recruit volunteers, both clinical and non-clinical, to help provide care to immigrants. They also respond to situations that arise internationally and are working to develop a system for rapidly deploying teams on short notice.

First consideration is to think about what we’d hope to get out of working with a group like this. The care they provide is largely clinic-based and focused on primary care, so if ambulance runs are what we’re looking for, this probably isn’t the best bet. If, however, you’re an EMS person looking to develop skills in the primary care setting, this may be a good fit. And if you know or want to learn Spanish, the ongoing projects they have in Mexico might be perfect.

Next is to consider prior experience with EMS providers. GRM has utilized EMS folks from the very beginning. In fact, many of their founding members were, and are, EMS people. This means they know exactly what we, as clinicians in this field, are capable of and trained to do. Additionally, this includes both EMTs and paramedics – they have availability for all. So even though the work itself may not fall into the standard EMS transport mold, there is a great deal of institutional experience in this area.

Lastly are the hurdles. GRM does require a bit of online training prior to deployment, but it’s relevant to the work they do. The process goes pretty quick and they have regular opportunities for volunteers, particularly at their Mexico projects. One more thing to mention is that GRM doesn’t require volunteers to pay to lend a hand – if you can agree to get there, they’ll put you to work.

As another example, there’s an organization called Raleigh International out of the UK that utilizes clinicians to provide medical support for volunteers on projects in the developing world. Raleigh takes young adults to different places around the world on “expeditions” that involve three phases: a community project focused on WaSH concepts, an environmental project geared towards natural resource management and an adventure leadership project that is essentially a backcountry trip of sorts to develop skills in leadership and resiliency; each one roughly three weeks long and the whole expedition is about three months in length.

The role of the medical provider in these expeditions is to provide medical support for the volunteers during various activities and while at project sites, not necessarily to care for people in the host country. Medical providers also function as project leads and, therefore, fill a sort of dual role. In addition, the medics (their generic term for docs, nurses and/ or paramedics) organize first aid training at the start of the expedition, field calls from non-medical project leads about cases that come up on sites, and staff a clinic during business hours when volunteers are at a field base in between phases of the expedition.

Just as before, if a 911-style experience is what you’re looking for, this probably isn’t the best opportunity. The medic side of the Raleigh experience is more of an add-on, with the focus on the projects themselves and helping volunteers get the most out of it (back to the dual-role idea we just mentioned). It’s also largely focused on intercultural exchange: volunteers are from both the UK and the host country, with some from the UK entering into the opportunity by way of scholarship programs. All that said, emergencies do come up, and that’s why they staff medics on these expeditions.

Moving on to experience with EMS clinicians: Raleigh does advertise medic positions for paramedics, but they are a UK-based program and the paramedic role across the pond is not 100% equivalent to what it is in the US. That said, it’s not an insurmountable hurdle and they have taken US paramedics (or at least one of us…) on projects in the past. We can’t speak to the AEMT/ EMT-I role, but it’d be worth an ask – especially for those with remote experience.

Just as before, the final consideration is the hurdles involved. The biggest one to mention is that Raleigh typically has a fee associated with its opportunities. This money goes to offset costs of the expedition and funds projects, but it can be a barrier to entry. That said, they do offer support for and actively encourage fundraising to offset this expense. Another thing to mention is that being a UK-based organization makes access to opportunities before and after an expedition difficult for those of us in the US. This also means that you’ll likely have to interview and work through the vetting process remotely via video chats. On that same note, Raleigh does a commendable job of maintaining a sense of community for those planning to and having participated in their opportunities, but nearly all of the associated social events, activities and opportunities take place in the UK. Which is totally understandable, just something to be aware of when getting involved from the US.

In light of those two in-depth examples, we’ll also mention a few other groups in passing without getting into the same level of detail – that’s on you if any of them seems like an opportunity you’d like to pursue. HERO Client Rescue in Haiti takes EMS providers of all levels to work on ambulances; if ambulance runs are what you’re looking for, this might be the ticket. Also in Haiti, Haiti Air Ambulance utilizes volunteer clinicians from HEMS programs in the US and Canada to augment their internal staffing. The opportunities are a bit more limited, but it’s an awesome rotor-wing experience if you have the time to make it happen. Team Rubicon also offers opportunities for EMS clinicians – these folks do all kinds of projects both domestically and internationally, all sort of focused on disaster/humanitarian response; some of which involve medical components.

Lastly, there are many organizations around the world that don’t have formal systems for recruiting volunteers that are, in fact, very much in need of motivated people willing to lend a hand. Don’t be afraid to reach out and initiate a dialogue. If you then decide that you can create and experience a new opportunity, do it. Make it happen, do good work, enjoy the ride, maybe even learn something new, and then reach out and let us know all about it when you make it back home!

Update Sep 2025: ConEd/ CEUs now available for this blog!

The series of illustrations in this post demonstrate the different types of dead space encountered in clinical practice and interventions to address them. Dead space is a concept that we generally discuss in the context of mechanical ventilation – this short series of graphics won’t get into too much detail on that, but we can point you towards our free book on the idea: www.rykerrmedical.com/clinical-resources/vent-management. The goal here is simply to review the different types of dead space, demonstrate them graphically, and point out specific interventions for each of the various types. And then real quick before we dive in: if you’re not familiar with the idea of dead space in general, it’s the concept that there is a difference between the quantity of air breathed in during a breath (tidal volume) and the volume of air that actually participates in gas exchange at the alveolar level (clinically relevant tidal volume). Hopefully the components of that volume of air will be clearer after reviewing the following illustrations.

The first type of dead space is anatomic dead space. Anatomic dead space represents the volume of gas inside of the body during a breath that cannot participate in gas exchange because it fills the conducting airways and doesn’t have the opportunity to interface with the alveoli. It essentially extends from the mouth to the terminal bronchioles where we begin to see alveolar sacs. One intervention to reduce this space is to use airway devices which eliminate anatomic dead space in the upper airway. Another way to reduce anatomic dead space when there is a need to increase minute volume (or minute ventilation, the volume of air moved in one minute) is to increase the volume of each breath (tidal volume) instead of the quantity of breaths (respiratory rate or frequency). This is due to the idea that the amount of anatomic dead space per breath is relatively fixed, so introducing more breaths adds dead space while adding volume to existing breaths simply adds to alveolar tidal volume.

The next type of dead space is alveolar dead space. Alveolar dead space refers to the volume of air within alveoli that is unable to fully participate in gas exchange due to some restriction of blood flow to those alveoli. Essentially the air within those under-perfused alveoli is wasted or not able to be used to its full capacity. Interventions to address alveolar dead space depend on the cause of the under-perfusion and are shown on the right hand side. Another term noted in this graphic is physiologic dead space. Physiologic dead space is the sum of anatomic and alveolar dead space and describes all of the dead space within a patient’s body.

The final type of dead space to demonstrate is mechanical dead space. Mechanical dead space, also known as equipment or apparatus dead space, is an additional quantity of dead space created by the devices we add into the system in order to administer treatments and interventions. Mechanical dead space is most relevant when using smaller tidal volumes (such as with pediatric patients), as the effect of mixing expired air with incoming air is more pronounced the smaller breaths are. Fixes include removing unnecessary items from a circuit and using appropriately sized pediatric devices.

And then to wrap it all up, here’s one last graphic that combines the various types of dead space into one visual:

Further reading on the idea:

· Vent management/ application of these ideas is covered in Rykerr Medical’s Vent Management Guide

· Super-detailed content on dead space from Deranged Physiology

· Anatomy review from a free online textbook by OpenStax

And one final closing thought: if you’re interested in creating content like this, we’d be happy to both help and share via our platform. The plan is that we’ll eventually be able to award continuing education to folks who contribute in this way. For more on all of that, check it out at www.rykerrmedical.com/coned-ceus.

Addendum, Sep 2021: The portion of the pie-charts labeled “clinically relevant tidal volume” had been previously notated as “alveolar tidal volume,” but we made this edit because we realized that such a label technically isn’t 100% accurate. Alveolar tidal volume includes both volume utilized (clinically relevant tidal volume) and volume wasted (alveolar dead space), so we needed a new descriptive term. Not sure if there’s a better term or one that already exists out there in the universe, but we’ll ask around and update this as needed.

Update Aug 2025 - This post was written a few years ago now, so it’s worth a quick update. The nature of the Rykerr Medical project has changed slightly and we never did get it worked out to offer CEUs for content creation as outlined below. That said, it is something we think about on occasion and we are definitely still open to the idea of others lending a hand with content creation. So if that’s something that seems like you’d be interested in, just reach out and we can diuscuss. Also we do have a CEU/ ConEd system worked out for other offerings, so take a look there if you need some hours or just want to learn some things.

Welcome to the Rykerr Medical Blog, a place where folks from around and across the medical industry can pitch in with ideas, thoughts, and expertise. Here’s how it works: Rykerr Medical LLC hosts this blog and will occasionally contribute content, but it’s mainly a platform for content created by other providers out in the field. And for the EMS folks, we are working to get accredited to award continuing education (CE) credits for contributions to both this project and a handful of others (for more on that, check out www.rykerrmedical.com/coned-ceus. This CE exchange will be totally free and will someday (hopefully!) be expanded to include our nursing colleagues. But to explain the whole idea in a bit more detail, we’re going to review how it all started and then outline how you can get in on it.

The idea with this project is twofold. First is that many clinicians in the field have valuable insight to offer, but not everyone has access to a platform or a mechanism to share that insight. Rykerr Medical is a way for these folks to contribute one-off content production with others in the field so that individuals who wish to give don’t have to mess with developing an entire project and/ or establishing a following to gain access to an audience. Second idea behind it all is that building or producing content is an awesome way to learn and establish one’s own understanding of something - this blog and other projects within the overall Rykerr Medical project allow clinicians to explore that avenue. The folks at Rykerr Medical and the community at large can offer feedback during and after, respectively, to help hone and refine ideas and specifics of a given presentation.

As for the workflow: if you’ve got an idea you’d like to explore, whether it be for this blog, the podcast, our YouTube channel, etc., just head on over to website and fill out an activity application (again, that’s at www.rykerrmedical.com/coned-ceus). Fill that out to let us know what you want to work on. The hope is that eventually your labor will be awarded with CEs, but for now it’s just for those warm fuzzies and the satisfaction of taking part in something awesome. And also your effort will help us finalize our application to get accredited and move this idea forward. Once you get the green light from us, you are free to develop away. Our volunteer committee will review your project once it gets submitted, compare against a rubric and either approve/ publish to the page or request revisions/ clarification as needed. It’s as simple as that!

It’s also worth mentioning that this program, even once we get accredited to award CEs, is entirely free to use. Rykerr Medical LLC (which includes this blog and the other projects mentioned above) and the continuing education program we are working to build is and will be free to users and operates via a network of volunteers. If you’d like to get involved on the back end of things as a content reviewer or in some other capacity, for sure reach out and we can have that conversation. And if you simply want to provide feedback in an informal capacity, you can leave comments here, drop us a note on the website, or get in touch via any of the social media things. More on it all and other fun things at www.rykerrmedical.com!