title: Lack of protective effect of tiotropium vs induced dynamic hyperinflation in moderate COPD.
abstract: OBJECTIVE
  Novel evaluation of protective effect of tiotropium against induced dynamic hyperinflation (DH) during metronome paced hyperventilation (MPH) in moderate COPD.
  
  
  METHODS
  Prospective, randomized, double-blind, placebo control, crossover study. Lung function measured pre/post MPH at 30 breaths/min for 20 s in 29 (18 M) COPD patients (GOLD Stage 2) age 70±9 yr (mean ± SD) before and after 30 days of 18 μg tiotropium bromide vs placebo. Lung CT scored for emphysema (ES).
  
  
  RESULTS
  At baseline post 180 μg aerosolized albuterol sulfate, FEV(1): 1.8±0.6 L (69±6% pred) and ≥60% predicted in all, and 14 of 29 had FEV(1) (L) ≥70% predicted with FEV(1)/FVC 58±8%. After 29 days + 23 h post tiotropium (trough) there was significant decrease only in FRC/TLC% (p=0.04); after 30 days + 2 h post tiotropium (peak) significant increase only in FEV(1) (L) (p=0.03) compared to placebo. Results post MPH induced DH at baseline and after 30 days and 2 h post placebo or tiotropium were similar with decrease in IC 0.44±0.06 L (p<0.001). Correlation between ES and increased FEV(1) (L) at peak tiotropium: r=0.19, p=0.96 and decreased FRC/TLC% at trough tiotropium: r=-0.26, p=0.36.
  
  
  CONCLUSIONS
  In moderate COPD, tiotropium did not reduce MPH induced DH and reduction in IC. However, at peak tiotropium, there was significant bronchodilation in FEV(1) (L) and at trough a decrease in FRC/TLC% compared to placebo despite varying emphysema.
authors.affiliation: Pulmonary Division, Department of Medicine, Lakewood Regional Medical Center, Lakewood, CA 90712, USA. afgelb@msn.com
authors.forename: Arthur F
authors.initials: AF
authors.lastname: Gelb
authors.forename: Christine
authors.initials: C
authors.lastname: Fraser
authors.forename: Noe
authors.initials: N
authors.lastname: Zamel
mesh_terms: D000368:Aged; D001993:Bronchodilator Agents / Q000008:administration & dosage / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D006985:Hyperventilation / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology*; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000503:physiopathology*; D012129:Respiratory Function Tests; D012602:Scopolamine Derivatives / Q000008:administration & dosage / Q000494:pharmacology*; D000069447:Tiotropium Bromide; D014057:Tomography, X-Ray Computed
chemical_list: D001993:Bronchodilator Agents; D012602:Scopolamine Derivatives; D000069447:Tiotropium Bromide