Patterns of response to inhaled methacholine.
Fifty-two patients with unexplained pulmonary symptoms were tested using inhaled methacholine. Of the 32 who reacted 11 had a greater than 20% decrease in FEV1 (with or without an associated change in FEF25-75%) as the end-point, 15 had a greater than 25% decrease in FEF25-75% as their initial response while 6 had an initial greater than 25% decrease in FEF200-1200. In some but not all subjects in the latter two groups a decrease in FEV1 occurred with increased methacholine concentrations. Changes in FEF25-75% and FEF200-1200 should be considered in documentation of airway hyperreactivity in some patients.
D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000175:diagnosis* / Q000188:drug therapy; D001985:Bronchial Provocation Tests; D001993:Bronchodilator Agents / Q000627:therapeutic use; D002648:Child; D005260:Female; D005540:Forced Expiratory Flow Rates; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008688:Methacholine Compounds; D008875:Middle Aged; D014797:Vital Capacity
D001993:Bronchodilator Agents; D008688:Methacholine Compounds