title: An attempt to determine the optimal duration of hospital stay following a severe attack of asthma.
abstract: The optimal duration of hospital stay following admission for acute severe asthma is difficult to determine. An asthmatic is at particularly high risk of sudden death in the 6-12 weeks after admission, and too early hospital discharge may add to this risk. Thirty patients hospitalised for severe asthma recorded peak flows thrice daily for 8 weeks following discharge. Peak flow charts were reviewed at monthly intervals, and dips were divided into 'minor' (peak flow less than 75% of the patient's best), 'major' (less than 50%) and 'catastrophic' (less than 30%). Fourteen of the 30 patients had major dips (including 4 who had catastrophic dips as well). Four of these 14 patients were readmitted with acute severe asthma during the 8 weeks follow-up period; in contrast, none of the 16 patients without major dips required readmission. The only in-hospital factor that correlated with and was predictive of (p less than 0.001) multiple major dips post-discharge was the peak flow variability in the 24 hours before discharge, defined as [(highest-lowest peak flow)/highest] x 100. Thirteen of the 14 patients with major dips had pre-discharge peak flow variation greater than 20% compared with only 2 of the 16 without major dips. We believe it is unwise to discharge asthmatics from hospital until the diurnal variation in their peak flow is below 20%. Discharging them before this target is reached puts them at increased risk of further severe attacks of asthma requiring re-hospitalisation.
authors.affiliation: Department of Respiratory Medicine, West Norwich Hospital.
authors.forename: Z F
authors.initials: ZF
authors.lastname: Udwadia
authors.forename: B D
authors.initials: BD
authors.lastname: Harrison
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D003645:Death, Sudden / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007902:Length of Stay; D008875:Middle Aged; D010351:Patient Discharge; D010359:Patient Readmission; D010366:Peak Expiratory Flow Rate; D011379:Prognosis; D013997:Time Factors