The Logistics Of Managing a Patient With Anaphylaxis


This week I taught the immunology section for my paramedic class.  I broke the class into groups to do case studies, and one was for a 12-year-old with anaphylaxis with stridor and difficulty breathing.  Towards the end of their treatment plan on the white board, the group wrote that they would intubate if the patient’s breathing difficulty did not improve after epi, Benadryl, and Solu-Medrol.  That lead to an interesting discussion.

I’m a big fan of Dr. Scott Weingard’s EmCrit podcast. One of his recurring themes is how logistics are more important than strategy during resuscitation.  For a case of worsening laryngeal edema, intubating s a great strategy.  It is what I was taught to do and is what our textbook says to do.  It is easy to write for a test question or say for a registry oral station.  What textbook neglects is the details about what is needed for one paramedic with an EMT partner to actually do this.  This is where I think EMS education often comes up short.

I probed the group about when they would want to intubate.  One member said early, so that their airway did not completely swell.  Let’s think about that.  Assuming no medications to facilitate intubation are available, the patient would have to be so hypoxic and fatigued that they lost most of their gag reflex, but their upper airway must open enough to pass an ET tube through.  How likely is that to happen?  RSI is available at some services in our area, but I believe it is far too dangerous for us to try in this situation.

Once the decision is made to intubate, packages must be opened and equipment must be prepared, all while someone attempts to ventilate the patient with a bag valve mask.  Manipulating the upper airway with a laryngoscope could make this situation much worse.  At the same time an epi infusion should be running at that point that will hopefully make this intubation unnecessary.  With no IV pumps, requires a drug calculation, medication draw, and drip rate to keep track of.  A good study recently showed that we are not very good at this in simulation, let along with real patients.

Worse, the stress that comes with managing a child in this situation would hinder performing all of these tasks.  The paramedic would lose fine motor skills and the ability to track time.  Steps in each procedure are likely to be missed, such as preparing suction before intubation.  Under stress we are more likely to continue failing strategies, even when others are available.  We know that intubation experience is correlated with outcomes for cardiac arrest and medical patients, and this is a situation that most paramedics will never see in their career.  Dave Grossman’s book On Combat provides a great explanation of why this happens..  I think that it is unrealistic to expect one paramedic to do all of these things – especially novice ones – and favor a simpler approach.

So the next question was what should we do.  Fortunately I’ve never been in this situation – all of my anaphylaxis patients have gotten better after one dose of IM epi.  Before I offer an opinion about something, I start by saying that my answer may not be the best one.  I encourage the students to ask the other instructors what they would do and to form their own opinions.  Then I said I do not think I would attempt to intubate.  I have never intubated anyone with an upper airway issue, and feel that the risk of me making the situation worse is too high.  I think I would focus my energy on fixing the anaphylaxis, managing the airway with basic interventions, and trying to get to the hospital before and advanced intervention was needed.

To fix the anaphylaxis, I think we should use EpiPens. That eliminates the steps needed to do math, open vials, and draw up medications under stress.  Any infusions should be on a pump, but until that happens I believe that Dr. Corey Slovis has the most logistically-friendly way to infuse epi.

As far as the airway, I would focus on ventilating with a bag-valve mask, with the goal of preoxygenating as much as possible before the occlusion is complete.  I would also do my best notify the hospital so that they could clear a room, get their crash airway equipment ready, and perhaps call an anesthesiologist.  This would give them time to prepare a strategy, and they would be in a better mindset to intubate than I would be in.  Otherwise, instead of a preoxygenated patient they may get a hyopoxic one with a laryngoscope-butchered upper airway. If there was no effective air exchange with bagging before we get to the hospital, then I would go straight to a surgical airway.  I think that the chance of that working is better than anything I could accomplish with a laryngoscope.

I want my students to be skilled intubators and to quickly calculate drug dosages.  I also want them to understand how difficult it is to do these things under extreme stress.  I want them to think about their limitations and what is best done at the hospital.  For a crashing anaphylaxis patient, I believe that’s with as little math as possible to deliver medications, basic airway management done really well, alerting the hospital, and a surgical airway if that fails. This is as simple as possible, but not too simple.

Comments

  1. Many people would heartily agree with a logistical focus, emphasizing autoinjector-delivered epinephrine, especially in children. I know of at least one tertiary-level pediatric ED that has switched to only autoinjectors for IM delivery.

    However, I wonder if we’re being overly conservative by saying “With no IV pumps, [epinephrine] requires a drug calculation, medication draw, and drip rate to keep track of.” Usually, I am 100% in agreement that vasoactive drugs need to go on a pump, but doing the math on Dr Slovis’s method is interesting.

    Using a 60-drop dripset, his method delivers 1mcg/minute at a rate of 60 drops a minute. Even when you double (or quadruple) the drip rate, you are only delivering 2 mcg (or 4 mcg) per minute, which is well within the max dosage range. If you can see individual drops, you’re somewhere in the 1-5 mcg/min range (Heck, even with a pressure bag, I think you would be hard-pressed to exceed 20 mcg per minute.)

    • emspatientperspective says:

      Thanks Brooks. The problem with any manual infusion is that it involves staring at a drip chamber for at least a few seconds, which requires attention to be taken away from the patient. The drip rate will also change if the patient bends their arm or the ambulance goes over a bump, which would be less of an issue with a pump. I do like Dr. Slovis’s methods, and the logistics of infusion without a pump is a good topic for another post.

      My biggest beef is what we teach about intubation for laryngeal edema or angioedema. I do not want intubation to go away, but do not think that many paramedics are skilled enough to do it in those situations. I think that a better approach would be to maximize oxygenation with a high-flow nasal cannula and NRB or BVM until there was no effective air exchange, which would buy you time to get to the hospital or do a surgical airway.

  2. I definitely appreciate your larger point! Preparing and placing an advanced airway has the potential to take up a good chunk of time (longer than 3-5 minutes), delaying appropriately aggressive IM redosing of epinephrine.

    Plus, in a hypotensive, redistributed patient, a dose of sedation (for RSI) might just send the blood pressure into the basement. Best to avoid that, as well as positive-pressure ventilation, until treatment with epi and saline is maximized!

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