title: Difficulty in obtaining peak expiratory flow measurements in children with acute asthma.
abstract: OBJECTIVE
  To determine the frequency with which children >or=6 years with acute asthma can perform peak expiratory flow rate measurements (PEFR) in an emergency department (ED).
  
  
  METHODS
  Data were obtained from a prospective cohort study of children with acute asthma. All children (age 2-18 years old) treated in an urban pediatric ED for an acute exacerbation during randomly selected days over a 12-month period were prospectively evaluated. According to treatment protocols, PEFR was to be measured in all children age 6 years and older before therapy and after each treatment with inhaled bronchodilators. Registered respiratory therapists obtained PEFR and evaluated whether patients were able to perform the maneuver adequately.
  
  
  RESULTS
  Four hundred and fifty-six children, 6 to 18 years old (median 10 years), were enrolled; 291 (64%) had PEFR measured at least once. Of those in whom PEFR was attempted at least once, only 190 (65%) were able to perform adequately. At the start of therapy, 54% (142/262) were able to perform PEFR. Of the 120 who were unable to perform initially, 76 had another attempt at the end of the ED treatment, and 55 (72%) were still unable to perform. A total of 149 patients had attempts at PEFR both at the start and end of treatment, of these, only 71 (48%) provided valid information on both attempts. Patients unable to perform PEFR were younger (mean +/- SD = 8.7 +/- 2.8 years) than those who were able to perform successfully (11.2 +/- 3.2 years) and those with no attempts (10.0 +/- 3.4 years). Children admitted to the hospital were more likely to be unable to perform PEFR (58/126 = 46%) than those discharged from the ED (43/330 = 13%, P < 0.0001).
  
  
  CONCLUSIONS
  Adequate PEFR measurements are difficult to obtain in children with acute asthma. Treatment and research protocols cannot rely exclusively on PEFR for evaluation of severity.
authors.affiliation: Section of Emergency Medicine, Department of Pediatrics, Medical College of Wisconsin, Milwaukee, USA. mgorelic@mail.mcw.edu
authors.forename: Marc H
authors.initials: MH
authors.lastname: Gorelick
authors.forename: Molly W
authors.initials: MW
authors.lastname: Stevens
authors.forename: Theresa
authors.initials: T
authors.lastname: Schultz
authors.forename: Philip V
authors.initials: PV
authors.lastname: Scribano
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D000367:Age Factors; D001249:Asthma / Q000503:physiopathology*; D002648:Child; D002662:Child Health Services / Q000706:statistics & numerical data; D002675:Child, Preschool; D015331:Cohort Studies; D004630:Emergencies; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D019983:Guideline Adherence; D006785:Hospitals, University / Q000706:statistics & numerical data; D006786:Hospitals, Urban / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D008297:Male; D010366:Peak Expiratory Flow Rate; D017410:Practice Guidelines as Topic; D011446:Prospective Studies; D015203:Reproducibility of Results