Factors associated with repeated use of epinephrine for the treatment of anaphylaxis.

BACKGROUND

Studies looking at the use of repeated doses of epinephrine in patients experiencing anaphylaxis are limited.

OBJECTIVE

To determine which patients are most likely to receive repeated doses of epinephrine during anaphylaxis management.

METHODS

A population-based study with medical record review was conducted. All patients seen during the study period who met the criteria for the diagnosis of anaphylaxis were included.

RESULTS

The cohort included 208 patients (55.8% female). Anaphylaxis treatment included epinephrine in 104 patients (50.0%). Repeated doses were used in 27 patients (13.0%), 13 (48.1%) of them female. The median age of those who received repeated doses was 18.9 (interquartile range, 10-34) years vs 31.1 (interquartile range, 15-41) years for those who did not receive repeated doses (P = .06). The inciting agents were food (29.6%), insects (11.1%), medications (22.2%), others (7.4%), and unknown (29.6%). Patients who received repeated doses were more likely to have wheezing (P = .03), cyanosis (P = .001), hypotension and shock (P = .03), stridor and laryngeal edema (P = .007), nausea and emesis (P = .04), arrhythmias (P < .01), and cough (P = .04) and less likely to have urticaria (P = .049). They were more likely to be admitted to the hospital than patients who did not receive repeated doses (48.2% vs 15.6%; P < .001). There was no significant difference in the history of asthma between patients who received repeated doses and those who did not (P = .17).

CONCLUSIONS

Of the patients, 13.0% received repeated epinephrine doses. Patients were younger and were likely to present with wheezing, cyanosis, arrhythmias, hypotension and shock, stridor, laryngeal edema, cough, nausea, and emesis and less likely to have urticaria. A history of asthma did not predict use of repeated doses of epinephrine. Our results help identify high-risk patients who may benefit from carrying more than 1 dose of epinephrine.