Prospective study of sudden-onset asthma exacerbations in children

Objectives: Sudden-onset asthma exacerbations among adults have more rapid treatment responses than do slower-onset exacerbations. We hypothesized that a similar pattern would be evident in children presenting to the emergency department (ED) with an asthma exacerbation. Methods: Prospective cohort study at 44 North American EDs. Parents of children, aged 2 to 17 years, underwent a structured interview in the ED and follow-up interview by telephone 2 weeks later. Results: Of 1184 enrolled children, 11% had sudden-onset asthma (ED presentation <= 3 hours after symptom onset). Sudden-onset patients were older than slower-onset patients (8.9 vs. 7.7 years, respectively; P = 0.004) and more likely to be white (26% vs. 17%, P = 0.01). They were less likely to report a history of steroid use or asthma hospitalization and reported fewer ED asthma visits during the past year (all P < 0.05). Although initial pulmonary index scores were similar (4.0 vs. 4.3, P = 0.24), patients with sudden-onset asthma were less likely to receive steroid treatment (73% vs. 84%, P = 0.002), had shorter ED length of stay (128 minutes vs. 150 minutes, P = 0.01), and in unadjusted analyses, were less likely to be admitted (16% vs. 24%, P = 0.04). Conclusions: Patients with sudden-onset exacerbations had similar acute asthma severity as those with slower-onset exacerbations but had shorter ED length of stay and were less likely to be admitted to the hospital, suggesting a more rapid response to treatment.