Anaphylaxis and hypertension?

[Ak68w]

Good afternoon Docs. I have a question regarding treatment of Anaphylaxis patients. I was talking about the subject with a nurse I work with (I work in an OR) and he said that in anaphylaxis with the standard issue hypotension, epi is the key, just like every EMT book ever written says. But then he said something interesting; that you must check BP in anaphylaxis patients because in the unlikely occurence that the patient is hypertensive, atropine is the treatment of choice.
My questions are:
1) Has anyone ever actually encountered this? Before the OR Nurse said it, I'd never even heard about it before.
2) If so, is the difference in BP due to the allergen itself, or simply the patient? Where and why does it happen?
3) As the medic, what happens if I give epinepherine to a hypertensive anaphylactic patient? What if I give atropine to the hypotensive guy?
4) Are there any other signs and symptoms of anaphylaxis that would dictate a radically different course of action (like giving epi versus atropine)?
The nurse was unable to answer many of these questions, simply because he's used to the controlled environment of the OR, whereas I'm curious about ramifications in unpredictable field environments. Anyways, I figured if anyone would know, it'd be you QPs! Thanks for any and all info.

[swatsurgeon]

before we discuss this further...use Google or WebMD and look up the indications for atropine. It is not a first line agent for anaphylaxis, it can be an adjunct. Read more then discuss....this is the way of education.

ss

[swatsurgeon]

well, I couldn't take it any longer.....
the nurse you speak of with great knowledge will potentially harm a patient who is having a true anaphylactic episode if atropine is given as a first line agent.
First off, the rxn causes hypotension not hypertension. If there is an element of hypertension than either (a) wrong diagnosis, (b) patient acute anxiety/agitation is occuring and temporarily increased BP over a brief period of time. Anaphylaxis causes the release of histamine and lowers BP, not raises it (under normal circumstances). All atropine will do is speed up the heart by blocking vagus nerve stimulation which is the overriding output/regulation to the heart.....
so query me this: how does a vagolytic drug treat anaphylaxis??
This is where education comes in.............

Ak 68w, i await your reply

ss

[adal]

ss,
You bit your tongue longer than I thought you would, 9 min. It became a topic of discussion here at my flight agency. Sad was the end result.

[Ak68w]

Originally Posted by swatsurgeon

First off, the rxn causes hypotension not hypertension. If there is an element of hypertension than either (a) wrong diagnosis, (b) patient acute anxiety/agitation is occuring and temporarily increased BP over a brief period of time. Anaphylaxis causes the release of histamine and lowers BP, not raises it (under normal circumstances).

That's why it seemed so odd to me when the nurse said it; I always thouhgt hypotension was a sign of Anaphylaxis. As far as the Atropine goes, before he had mentioned it, I knew the name, I knew it was a beta blocker, and I knew it helped patients with uncontrollable tremors (i.e., Parkinsons) and certain over-productive glands. Beyond that, I knew nothing of the drug as far as emergency indications/contraindications, what exactly it does, etc. etc.

Now you said that histamine lowers not raises BP, under normal circumstances. Do you mean normal as in normal patients, or normal conditions? If the latter, what preparations and precautions should I as the medic take when my unit and I take to the field? And what should I do then if I find a hypertensive anaphylactic patient? Thank you for this info SS!

[swatsurgeon]

Originally Posted by Ak68w

That's why it seemed so odd to me when the nurse said it; I always thouhgt hypotension was a sign of Anaphylaxis. As far as the Atropine goes, before he had mentioned it, I knew the name, I knew it was a beta blocker, and I knew it helped patients with uncontrollable tremors (i.e., Parkinsons) and certain over-productive glands. Beyond that, I knew nothing of the drug as far as emergency indications/contraindications, what exactly it does, etc. etc.

Now you said that histamine lowers not raises BP, under normal circumstances. Do you mean normal as in normal patients, or normal conditions? If the latter, what preparations and precautions should I as the medic take when my unit and I take to the field? And what should I do then if I find a hypertensive anaphylactic patient? Thank you for this info SS!

hold on......IT IS NOT A BETA BLOCKER!!!!! please do some research on this!!
You should rarely if ever find a patient with hypertension and anaphylaxis. The 'under normal circumstances' means the majority of patients...not the ones on crack/meth/etc or medications that raise the BP. Again, read about the subject of anaphylaxis and atropine, it will do more for you than reading my posts, I'm just an ordinary trauma surgeon

ss

[Red Flag 1]

if it worth saying, it will be quoted.