title: Effect of an additional 1-hour T-piece trial on weaning outcome at minimal pressure support.
abstract: OBJECTIVE
  The purpose of this article was to investigate the effect of an additional 1-hour T-piece trial at the level of minimum pressure support (PSmin) on weaning outcome.
  
  
  METHODS
  Open, randomized, prospective study of 44 patients who had received mechanical ventilation for more than 3 days.Thirty-six patients satisfied the protocol. There were 42 weaning trials. The patients were randomized into an intervention group (additional 1-hour period of T-piece trial) and a control group (extubation directly) at PSmin. Blood gas analysis and estimation of respiratory and hemodynamic variables were performed at the 15 cm H2O level of pressure support. Measurements were repeated at PSmin and during weaning process (in intervention group).
  
  
  RESULTS
  Mean PSmin level was 7.6 (+/- 1.9) cm H2O. There were no differences in total ventilation time (TVT), acute physiology and chronic health evaluation (APACHE) II score, nutritional indices, and respiratory mechanics on PSmin between the two groups. The weaning success rate and the reintubation rate were similar for the intervention group (55% and 18%, respectively) and control group (70% and 20%, respectively). Work of breathing, pressure time product, and tidal volume significantly worsened after a 1-hour T-piece trial when compared with those values measured at PSmin in the intervention group (P < .05). For the combined patient sample, TVT and tidal volume at PSmin were significantly different between the patients with weaning success (246 +/- 195 hours, 0.43 +/- 0.11 L) and those with weaning failure (407 +/- 248 hours, 0.35 +/- 0.10 L) (P < .05 in each).
  
  
  CONCLUSIONS
  There were no advantages in weaning outcome by the addition of a 1-hour T-piece trial compared with prompt extubation at PSmin.
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Y
authors.initials: Y
authors.lastname: Koh
authors.forename: S B
authors.initials: SB
authors.lastname: Hong
authors.forename: C M
authors.initials: CM
authors.lastname: Lim
authors.forename: S D
authors.initials: SD
authors.lastname: Lee
authors.forename: W S
authors.initials: WS
authors.lastname: Kim
authors.forename: D S
authors.initials: DS
authors.lastname: Kim
authors.forename: W D
authors.initials: WD
authors.lastname: Kim
mesh_terms: D018806:APACHE; D001784:Blood Gas Analysis; D005260:Female; D006439:Hemodynamics; D006801:Humans; D008297:Male; D008875:Middle Aged; D011175:Positive-Pressure Respiration; D011446:Prospective Studies; D012131:Respiratory Insufficiency / Q000097:blood / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D013990:Tidal Volume; D013997:Time Factors; D016896:Treatment Outcome; D015300:Ventilator Weaning / Q000295:instrumentation* / Q000379:methods*; D014939:Work of Breathing