Effect of an additional 1-hour T-piece trial on weaning outcome at minimalpressure support

Purpose:The purpose of this article was to investigate the effect of an add itional 1-hour T-piece trial at the level of minimum pressure support (PSmi n) on weaning outcome. Materials and Methods: Open, randomized, prospective study of 44 patients w ho had received mechanical ventilation for more than 3 days. Thirty-six pat ients satisfied the protocol. There were 42 weaning trials. The patients we re randomized into an intervention group (additional 1-hour period of T-pie ce trial) and a control group (extubation directly) at PSmin. Blood gas ana lysis and estimation of respiratory and hemodynamic variables were performe d at the 15 cm H2O level of pressure support. Measurements were repeated at PSmin and during weaning process tin intervention group). Results: Mean PSmin level was 7.6 (+/-1.9) cm H2O. There were no difference s in total ventilation time (TVT), acute physiology and chronic health eval uation (APACHE) II score, nutritional indices, and respiratory mechanics on PSmin between the two groups. The weaning success rate and the reintubatio n 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-piec e trial when compared with those values measured at PSmin in the interventi on group (P < .05). For the combined patient sample, NT and tidal volume at PSmin were significantly different between the patients with weaning succe ss (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). Conclusion:There were no advantages in weaning outcome by the addition of a 1-hour T-piece trial compared with prompt extubation at PSmin. Copyright ( C) 2000 by W.B. Saunders Company.