Fig. 4

Flowchart depicting Epinephrine Usage, Doses, and Timings. 138 anaphylactic events were sub-categorized into uniphasic, non-anaphylactic biphasic, and biphasic events. Patients who received epinephrine in each group were identified, and sub-analyses of epinephrine dosage and timing of dose administration relative to ED arrival were conducted. No significant differences were found between the first epinephrine dosage across each responder group (p = 0.9179, Kruskall-Wallis test). Among patients who received their first dose of epinephrine before ED arrival, there was no significant difference in the time between the first dose administration and ED arrival for uniphasic, non-anaphylactic biphasic, and biphasic responders (p = 0.6283, Kruskall-Wallis test). Similarly, among patients who received their first dose of epinephrine after ED arrival, there was no significant difference in the time between ED arrival and the first dose administration for uniphasic, non-anaphylactic biphasic, and biphasic responders (p = 0.4787, Kruskall-Wallis test). The timing of epinephrine administration and ED arrival was comparable among the responder groups (p > 0.05, Mann–Whitney test)