Columns, Patient Care

Pediatric Anaphylaxis Study Lacks Crucial Details

Issue 10 and Volume 41.

The Research

Carrillo E, Hern HG, Barger J. Prehospital administration of epinephrine in pediatric anaphylaxis. Prehosp Emerg Care. 2016;20(2):239–244.

The Science

To assess the rates of administration of epinephrine, diphenhydramine (Benadryl) and albuterol to children with allergic reactions including anaphylaxis, the authors reviewed the EMS records of Contra Costa County and Alameda County in California from January 2010 to July 2011. Combined, the two counties serve a population of about 2.3 million people.

Of the slightly more than 239,000 patient contacts and 13,000 pediatric transports, paramedics treated 205 pediatric patients with allergic complaints; 98 of these cases had signs and symptoms consistent with anaphylaxis and therefore would be candidates to the administration of epinephrine. However, only 53 (54%) were given epinephrine either by EMS or prior to the arrival of EMS.

Of those not given epinephrine prior to EMS arrival, only six (12%) received epinephrine by EMS, 10 (20%) received only diphenhydramine, nine (18%) received only albuterol, and 17 (33%) received both albuterol and diphenhydramine. Nine (18%) of the patients received no treatment prior to hospital arrival.

Patients with a history of anaphylaxis were more likely to receive epinephrine than those without a history (45% vs. 5%, respectively).

Medic Wesley Comments

I read this study twice to be sure that I hadn’t missed the ultimate goal of patient outcomes. It wasn’t there.

Although epinephrine is the initial recommended lifesaving medication in cases of true anaphylaxis, oftentimes the exposure occurs in distracted children and it isn’t noticed until many minutes, if not hours, have passed.

Parents, teachers and caregivers providing supervision and are more likely to observe symptoms of allergic reaction or anaphylaxis. In this study, they also provided epinephrine when it was indicated.

In my experience, even with the rising number of childhood allergies, the majority of EMS allergy patients are fairly stable, presenting with mild lingering symptoms such as localized swelling, itching and wheezes.

This isn’t to say there weren’t cases of true anaphylactic reaction in this study, but without the important information of patient outcome, objective signs and symptoms, incident to response times, and vital signs on arrival, I have to say this study doesn’t lead me to change
my practice.

Doc Wesley Comments

At first blush, this paper appears to a sobering commentary on the current inability of EMS to provide potentially lifesaving care for patients with anaphylaxis. Although it’s clear anaphylaxis “can” be deadly, the authors provide no outcome data for these patients. Was there a difference in the rate of hospitalization, length of stay and mortality between those treated and those not? Let’s assume there was. Why did some patients get epinephrine and others Benadryl and/or albuterol?

We’ve taught, and most protocols support, that epinephrine is indicated when any of the criteria in Table 1 exist; the authors provide no information on these signs and symptoms. Were certain presentations such as hives with a swollen tongue not recognized as anaphylaxis? Was wheezing noted but small hives not given any significance leading to albuterol alone? Without knowing this, it’s difficult to know what we should concentrate on in education.

But one thing is clear: Anaphylaxis is rare in these two counties, representing less than nine-tenths of 1% (0.09%) of all patient transports. It’s no surprise that it wasn’t recognized and treated accordingly.

Childhood anaphylaxis is a terrible condition and we know how careful parents of children with severe allergies must be but we shouldn’t use this study to indicate that all is lost when it comes to prehospital care of anaphylaxis.

Table 1: Definition of anaphylaxis

Criteria 1: Acute onset involving skin, mucosal tissue, or both and at least one of the following:
A) Respiratory compromise, or
B) Reduced blood pressure or associated symptoms of end organ dysfunction (hypotonia, syncope, incontinence)

Criteria 2: After exposure to a likely allergen, two or more of the following:
A) Involvement of the skin/mucosa
B) Respiratory compromise
C) Reduced blood pressure or associated symptoms of end organ damage (syncope, incontinence)
D) Persistent gastrointestinal symptoms (abdominal pain, vomiting)

Criteria 3: Reduced BP after exposure to known allergen
A) Reduced BP in an adult is < 90 mmHg systolic or 30% decrease compared to baseline systolic BP
B) In infants and children, reduced is low BP by age or 30% decrease in systolic BP