Circadian differences among 4,096 emergency department patients with acuteasthma

Introduction: In patients with asthma, airways narrow during the night, The clinical implications of a nocturnal presentation of patients with acute a sthma to the emergency department (ED) are uncertain. Objective: Our objective was to determine whether patients with asthma who had ED visits during the night (midnight to 7:59 am) vs, other times were m ore severe, responded less well to ED therapy, and had worse clinical outco mes. Design and Setting: We performed a cohort study, as part of the Multicenter Airway Research Collaboration (n = 77 sites). ED patients with acute asthm a, ages 2-54 yrs, underwent a structured interview in the ED. Chart review of missed/refusal patients created a truly consecutive case series. Measurements and Main Results: Among 1,602 children, 19% presented at night . Nighttime patients were more likely to be younger, male, and have a short er duration of symptoms; there were no other clinical differences noted, Am ong 2,494 adults, 20% presented at night, and they were more likely to be f emale and to have a history of steroid use for asthma, Nighttime adults als o had a shorter duration of symptoms and slightly lower peak flows (mean, 4 5% vs, 49% of predicted; p = .006) and were more likely to receive steroids , They were more likely to be intubated (2.0% vs, 0.2%; p < .001), but, ove rall, they were equally likely to be admitted or relapse after ED discharge . In contrast to objective measures of acute asthma severity, both nighttim e children and adults were significantly less likely to report their asthma symptoms as severe. Conclusion: Except for endotracheal intubation (in adults only), circadian differences minimally affect ED presentation, therapy, or the outcomes of a cute asthma, Nighttime asthmatics may be relatively insensitive to the symp toms of severe asthma.