Questions for EMTs/Medical Pros on backcountry anaphylaxis treatment

Hoodie

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I don't have any severe allergies that I'm aware of, but I've heard a few recent horror stories about people who found out they did in less than ideal circumstances.

Epi-Pens are prescription only apparently. But there's an OTC epinephrine inhaler available for asthma.

1) Given that the whole problem with anaphylaxis is airway constriction, is carrying something like this inhaler a decent option if an epi-pen isn't feasible? I've read a few studies and realize the injector would be more effective, but is an inhaler better than nothing? Could severe airway constriction come on so quickly that inhaled medications wouldn't be a viable option?

2) I have an albuterol inhaler for occasional asthma flare-ups. Would this be an okay thing to use in addition to the epinephrine to keep an airway open? Again, I'm aware that this is way less than ideal. I'm more concerned about potential problems with using both drugs at the same time.

3) I've read a few people suggest that chewable Benadryl is superior to pills in the event of a severe reaction because the chewables have a more immediate impact on the mouth/throat. Any reason to think this is the case? (I'm aware that the chewable dosage is lower and that you'd need to take more to account for this.)

Thanks in advance
 

HuntWyld

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What kills people in anaphylactic reactions is actually hypotension from systemic vasodilation. The Epi injection either venous or intramuscular combats this with systemic vasoconstriction. Yes there is airway constriction during these events and your inhaled Epi idea has potential to possibly be helpful for this but it’s likely not a high enough dose given that route to combat any hypotension. Albuterol works on the bronchioles which are lower in the lungs and in anaphylaxis the airway issues are in the upper portions of the airway so this has little benefit. Carry some Benadryl for mild reactions and if your still worried about it then get a doc to write you a script for a pen, explain the situation and often times physicians are understanding.
 

Marbles

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I would not bother with it. For someone in true anaphylaxis it might be better than nothing, but probably inadequate to save a life.

Anaphylaxis is a systemic problem, respiratory distress is only one aspect, low BP also kills in anaphylaxis.

Adult IM epi dose for anaphylaxis is 0.5mg every 5-15 minutes (and sometimes more frequently). Epi inhaler is 0.125mg (so 4 puffs is the same mg). Problem is it is not systemically absorbed very well. 15 puffs of 0.16mg epi inhaler (2.4mg) still results in lower serum levels than a single IM injection of 0.3mg. An additional 30 puffs (45 total) does get hire serum concentration than 0.3mg IM, however the serum concentration falls more rapidly for the inhaled epi, meaning more frequently repeat doesing would be needed.
httpss://pubmed.ncbi.nlm.nih.gov/3780129/

Someone in true anaphylaxis is unlikely to be able to coordinate the inhalations correctly (and may even be unconscious) making efficacy even lower. An asthmatic would have a better chance as they are practiced at using an inhaler. If I only had inhaled epi and someone was in anaphylaxis I would give it a shot, but I certainly would not carry it for the purpose as it will probably give the same result as no treatment at all.

Benadryl is worth carrying, but it also will not save someone in true anaphylaxis.

@HuntWyld gave an excellent answer.
 
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Rob5589

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Anaphylaxis is a system wide reaction that causes extreme vasodilation which results in hypotension, vascular leakage, severe respiratory compromise, organ failure, and death. It requires very aggressive management with high doses of epinephrine and a lot of fluid resuscitation. If one were to go into anaphylaxis in the back country their odds of survival are extremely low. It kills people that we aggressively treat that live only minutes from the hospital.

Allergic reactions can be somewhat managed with an Epi pen and diphenhydramine but those people still need to get to definitive care very quickly. An Epi pen is simply to stave off a worsening reaction, not to eliminate it completely.
 

ColeyG

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A few other considerations re: epi pens in the field.

1. They have a limited life span. Most expire 18 months after they are issued but "should" still work for a period of time after that. Plenty of people toss an epi pen in their first aid kit and forget about it for years assuming they will be good to go when/if they need it.

2. Epi pens are both hot and cold sensitive. If they get too hot and/or too cold for too long, the medication won't work. What temps and exposure times does it take to ruin epi isn't perfectly understood as far as I am aware, but repeated freezing and thawing and/or sitting in a hot car for a few days will ruin the drug.

An anaphylaxis plan should include Epi and Benadryl/diphenhydramine or steroid like Prednisone. In theory Epi keeps the airway open and problems at bay long enough for the diphenhydramine, etc. to do their thing over time.
 
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Im not a medical expert at all, but my wife carries an epi for idiopathic anaphylaxis and also carries benadryl. No idea if the other commenters have an MD, but would highly recommend you talk to a physician. There is more to this stuff than a google search...

Both the Epi and Benadryl have saved my wife’s life many times. We hike and camp remote all the time. Here’s my non medical advice, if your physician thinks you need to carry an EPI, carry two!
 

Rob5589

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A few other considerations re: epi pens in the field.

1. They have a limited life span. Most expire 18 months after they are issued but "should" still work for a period of time after that. Plenty of people toss an epi pen in their first aid kit and forget about it for years assuming they will be good to go when/if they need it.

2. Epi pens are both hot and cold sensitive. If they get too hot and/or too cold for too long, the medication won't work. What temps and exposure times does it take to ruin epi isn't perfectly understood as far as I am aware, but repeated freezing and thawing and/or sitting in a hot car for a few days will ruin the drug.

An anaphylaxis plan should include Epi and Benadryl/diphenhydramine or steroid like Prednisone. In theory Epi keeps the airway open and problems at bay long enough for the diphenhydramine, etc. to do their thing over time.
Benadryl won't do anything for anaphylaxis. One .5 mg of Epi won't either. We treat anaphylaxis with intravenous epinephrine and a lot of IV fluids, something like 4-8 liters depending on severity. And people still die. Anaphylaxis in not the same as an allergic reaction. Not even close.
 
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Im not a medical expert at all, but my wife carries an epi for idiopathic anaphylaxis and also carries benadryl. No idea if the other commenters have an MD, but would highly recommend you talk to a physician. There is more to this stuff than a google search...

Both the Epi and Benadryl have saved my wife’s life many times. We hike and camp remote all the time. Here’s my non medical advice, if your physician thinks you need to carry an EPI, carry two!
I should add, shes never had anaphylaxis while hiking/camping. After you inject epi you have to go to ER. Shell take benadryl as a prophylactic depending on symptoms. But if she had a reaction wed have to haul ass to the trail head or hope our InReach gets a chopper to us quick.
 
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Benadryl won't do anything for anaphylaxis. One .5 mg of Epi won't either. We treat anaphylaxis with intravenous epinephrine and a lot of IV fluids, something like 4-8 liters depending on severity. And people still die. Anaphylaxis in not the same as an allergic reaction. Not even close.

Anaphylaxis is a severe allergic reaction... what are saying? I think i get what you mean, they are a definite life threatening situation, but still an allergic reaction.
 

Rob5589

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Anaphylaxis is a severe allergic reaction... what are saying? I think i get what you mean, they are a definite life threatening situation, but still an allergic reaction.
An allergic reaction is a localized reaction; hives, runny nose, itchy skin. Anaphylaxis is a multi system reaction; shortness of breath, swelling to airways, tachycardia. Anaphylactic shock involves potentially all of that plus hypotension/vascular dilation, altered mentation. An allergic reaction can become an anaphylactic reaction which can become anaphylactic shock.
 
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I’m with Rob5589. If you need an epipen in the backcountry you are pretty screwed and will need more than one of them, as well as extraction ASAP. It works for a couple hours and needs redosing if it’s a bad enough reaction. Benadryl can help with some of the discomfort but it’s not life saving by any means.

I think unless you have a true, severe allergy it is not wise to carry an epi pen. Its not a safe medication if you were to give it to someone when they didn’t truly need it. If I had a severe allergy and I was backpacking or away from cell service then I would have an in-reach as well as extra epi pens. I am an MD just FYI and I’m guessing there’s some others on here based on their responses.
 

Backyard

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Sounds like it´s not worth the weight then.

I appreciate the thorough, detailed responses.
FWIW My 2 pens weigh 5.2 oz together. I'll be carrying mine.
The one big drawback is that the manufacturers know that these can be life or death for some, and they price them accordingly. Over $400 for the pair. Used Good Rx coupon tho - $125.
 

Wellsdw

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Auto injector industry standard is .3 mg. I’ve administered them professionally and used them personally. (For bees) An antihistamine almost always has to accompany the injection. One fixes the symptoms, one stops the reaction. If you don’t stop the reaction then epi can burn off as it quickly and wears off. Something to keep in mind is if your tongue swells or your throat, you may not be able to chew or swallow Benadryl. Generally speaking your first true anaphylactic reaction will be slower than the ones in the future. I always carry chewable Benadryl and usually epi. My .02

Benadryl for severe allergic reaction is 1mg per kg per our jurisdiction protocols
 

406

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What kills people in anaphylactic reactions is actually hypotension from systemic vasodilation. The Epi injection either venous or intramuscular combats this with systemic vasoconstriction. Yes there is airway constriction during these events and your inhaled Epi idea has potential to possibly be helpful for this but it’s likely not a high enough dose given that route to combat any hypotension. Albuterol works on the bronchioles which are lower in the lungs and in anaphylaxis the airway issues are in the upper portions of the airway so this has little benefit. Carry some Benadryl for mild reactions and if your still worried about it then get a doc to write you a script for a pen, explain the situation and often times physicians are understanding.
We did the math one day and you'd need about half of that epi MDI.

Liquid oral benedryl and bronkaid are what you are looking for. Vasoconstrictor and bronchodilator.

Sent from my Pixel 2 XL using Tapatalk
 

Tod osier

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we carry one and Benadryl on serious backcountry trips. My wife had a reaction years ago and was treated with one, so it falls in the better safe than sorry category.

funny story about cost of one and prescriptions... several years ago we went to our family dr to refresh our med supply for and ALaska fly in trip and got prescribed the usual inexpensive travel meds (augmentin, flagyl, cipro, etc...) and an epipen. We were at the drive through pharmacy to pick it up and the bill was 1200... we were confused and when we asked there was a 12 pack of epi pens on the prescription. Needless to say, we only got 1.
 

Rob5589

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we carry one and Benadryl on serious backcountry trips. My wife had a reaction years ago and was treated with one, so it falls in the better safe than sorry category.

funny story about cost of one and prescriptions... several years ago we went to our family dr to refresh our med supply for and ALaska fly in trip and got prescribed the usual inexpensive travel meds (augmentin, flagyl, cipro, etc...) and an epipen. We were at the drive through pharmacy to pick it up and the bill was 1200... we were confused and when we asked there was a 12 pack of epi pens on the prescription. Needless to say, we only got 1.
The price of epi pens is insane.
 
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