title: Evaluation of a new method for measurement of minute ventilation recovery time.
abstract: OBJECTIVE
  To determine if the measurement of minute ventilation recovery time (V (E)RT), a recently proposed predictor of extubation outcome, can be reproduced using a more practical, simpler method.
  
  
  METHODS
  A case series with convenience sampling was performed in the surgical intensive care unit of a tertiary-care hospital. Nineteen patients were enrolled during weaning from mechanical ventilation, prior to the initial extubation attempt. Within-subject comparisons of V (E)RT were performed, using 2 alternative methods for measuring baseline V (E) and one alternative method for determining the threshold for recovery of V (E) during the final spontaneous breathing trial prior to extubation. Comparison methods for baseline V (E) included an 8-hour average and the last V (E) measurement prior to the spontaneous breathing trial. The alternative threshold for defining recovery of V (E) was 100% of the baseline value (vs 110% in the original method).
  
  
  RESULTS
  The study subjects were primarily cardiac surgery patients (63%) and were ventilated for a median of 5 days prior to extubation. V (E)RT calculated using the 8-hour average or the last V (E) measurement prior to the spontaneous breathing trial as baseline, and a threshold of 100% of baseline V (E) to define recovery most closely approximated V (E)RT obtained by the original method and similarly classified patients at high risk for reintubation (kappa statistic = 0.78 +/- 0.2).
  
  
  CONCLUSIONS
  V (E)RT can be determined using a simpler method for measuring both baseline V (E) and the recovery threshold. These methodological modifications may increase the feasibility of measuring V (E)RT, while reproducing the results obtained by the original method.
authors.affiliation: Department of Medicine, Hospital of the University of Pennsylvania, Philadelphia, Pennsylvania 19104-4283, USA.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Seymour
authors.forename: Jason D
authors.initials: JD
authors.lastname: Christie
authors.forename: Christina A
authors.initials: CA
authors.lastname: Gaughan
authors.forename: Barry D
authors.initials: BD
authors.lastname: Fuchs
mesh_terms: D000328:Adult; D000368:Aged; D020878:Device Removal / Q000379:methods; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012123:Pulmonary Ventilation; D020127:Recovery of Function; D015656:Respiratory Mechanics; D013990:Tidal Volume; D013997:Time Factors; D015300:Ventilator Weaning / Q000379:methods*