Racemic epi in allergic reaction

[runswithneedles]

We did a pediatric scenario lab recently and one of which was a 6 y.o female which had a severe allergic reaction secondary to a bug bite. She had a Hx of asthma and seasonal allergies and NKDA. And last time she had anything to eat or drink was lunch several hours prior. Her signs and symptoms came on 20 minutes prior to EMS arrival. Had I did a full body exam I wouldve found the moulaged bug bite on her left shoulder and known it was a severe allergic reaction. (sorry if my spelling is off) Her pulse was 140 BP 100/75 Resp around 40 SPO2 98% RA. My primary diagnosis was severe asthma attack and my differential was a allergic reaction from a unknown etiology. My treatments were begin pt on racemic epi via nebulizer mask 8LPM, begin IV access at TKO for drug administration, and transport code 3 to nearest emergency facility. When my instructor told me I had the incorrect diagnosis and what needed to be done it made me wonder as to if the treatment I had rendered would have been detrimental or beneficial to the patient. My theory behind the racemic epi was she was nearly maxed out on her albuterol treatments and if was indeed a allergic reaction it might alleviate it or if it was a severe asthma attack it would open up her bronchioles. What are your thoughts on it

[DwayneEMTP]

How did you reconcile the B/P with the rest of her symptoms when you diagnosed the asthma attack?

With a patient in this state wouldn't you have expected a catecholamine dump, vasoconstriction and a relatively elevated B/P? I swear that I'm not bagging on your Brother, just voicing my thoughts. What do you think?

Also, and I'll ask that you believe that this isn't a criticism but a preference only....I like your posts, but could you break your larger posts up into smaller paragraphs? It just makes it easier for old People like the Mike's and DFIB to read. Me? No problem...I'm just trying to watch our for our brothers...

As to the Recemic epi, I'd have to Google it as I have never used it and have no idea off of the top of my head...we'll wait for the smart folks to work that out for you.

Good post!

[runswithneedles]

I was thinking the increased BP was from anxiety from the asthma attack and the increased heart rate from the albuterol combined with the anxiety. And the reason why I posted was for constructive criticism. So im not taking it as bagging at all.

And I'll be sure to begin breaking up large posts into paragraphs. Along with double spacing.

The little research ive done between the racemic epi and the epi IM was the dosing and I think the concentration (I cant remember specifically as this scenarion was done three weeks ago). But im curious as what kind of impact between the different route, dosing, and concentration would have for this patient.

Since both asthma and allergic reaction constrict the airway the racemic epi seemed like a way to knock out two birds with one stone.

But to be straight forward I think I got so tunnel visioned on the asthma I ignored anything else.

[chbare]

A couple of points:

Racemic is a word that is typically used in chemistry to identify a solution that has a 1:1 mixture of enantiomers. These are almost always optically active as far as I know. In that I mean you have an isomer that demonstrates levo-rotatory and an isomer that demonstrates dextro-rotatory, commonly called L & D. Basically, light will travel around the D in a clockwise fashion and around the L in a counterclockwise fashion (specifically, the plane of polarisation is rotated). Many biological molecules such as sugars and amino acids share this property where you essentially have a molecule that has two "mirror images." This also includes many medications. With that, a D and a L molecule may have very different properties. In the case of epinephrine, we typically use the highly active L form but racemic mixtures include the D form.

With all that said, racemic epinephrine has numerous side effects and is typically used for it's alpha effects on subglottic mucosal layers (treating stridor). While racemic epinephrine has Beta effects and can cause bronchodilation, you are probably better off using a medication such as albuterol that has more specific Beta 2 effects and less Beta 1 crossover. While I do not totally disagree with your treatment if stridor did in fact exist, your rational for choosing a certain treatment was flawed to an extent.

[runswithneedles]

.....crap

[Kiwiology]

Her symps and obs do not fit with somebody who has been having an asthma attack for 20 minutes. Patients who present with severe or life threatening asthma have have been having active symps tor many hours that slowly progress to a point where they become so fatigued and hypercapoenic they can no longer compensate.

On the other hand, she presents exactly as you would expect somebody who is having a severe allergic reaction. It is not yet what I would call anaphylaxis but its going to go there if you don't do anything. I am struggling to think of whether I would give this child parenteral adrenaline or not, but that is really not what you are asking.

Nebulised adrenaline is only appropriate for severe croup or severe stridor. It is theoretically possible to give somebody with asthma or anaphylaxis nebulised adrenaline but probably won't do a lot.

[JakeEMTP]

What do your protocols say is the treatment of an allergic reaction? I know we preach here to think outside the box and not to be a cookbook medic, sometimes however, the Doctors do know best.

The scenario was for an allergic reaction right? So, O2, Benadryl, IM Epi, Solumedrol. You state she had maxed out on her Albuterol (which I assume was a metered-dose inhaler. I also assume she wasn't getting any relief from that due to breathing 40x/min). Nebulized Albuterol, Combivent or Atrovent I think would be preferred over nebulized Epi.

Kudos for coming on and sharing this. That is what scenarios are for. Lonestar used to to say, "kill 'em in the classroom so you can save 'em in the streets" or something like that. Tunnel vision is a major stumbling block for students. I did it and I'm sure most here did it. I see it in students all the time. You will have to get over that to be successful. I have faith in you though!

[runswithneedles]

Is it common for patients to not show hives during a allergic reaction? That was one of the key factors that made me rule out allergic reaction as a primary diagnosis. Because in this scenario she had not developed that nor was she experiencing the sensation at the time of her throat swelling or anything. It was only wheezing at the time. Sorry I didnt post that in the original.

[runswithneedles]

As far as the cookbook medic the idea seemed sound at the time. Looking at it now I couldve accomplished the same method of killing two birds with one stone by doing the epi IM. With respirations at 40+ i'm starting to think the nebulized epi wouldve been useless because the tidal volume (or is it inspiratory volume? I need to double check that) wouldve been insufficient.

[Kiwiology]

They can have any combination of wheezing, hives, stridor, hypotension, angioedema or tachycardia; just because they do not have hives or any other symptom does not mean that it is not an allergic reaction.

Nebulised adrenaline is not a treatment for systemic allergic reaction; it is a treatment for angioedema; a patient who is "sick" enough needs parenteral adrenaline.