EXTUBATION OUTCOME AFTER SPONTANEOUS BREATHING TRIALS WITH T-TUBE OR PRESSURE SUPPORT VENTILATION

A 2-h T-tube trial of spontaneous breathing was used in selecting pati ents ready for extubation and discontinuation of mechanical ventilatio n. However, some doubt remains as to whether it is the most appropriat e method of performing a spontaneous breathing trial. We carried out a prospective, randomized, multicenter study involving patients who had received mechanical ventilation for more than 48 h and who were consi dered by their physicians to be ready for weaning according to clinica l criteria and standard weaning parameters. Patients were randomly ass igned to undergo a 2-h trial of spontaneous breathing in one of two wa ys: with a T-tube system or with pressure support ventilation of 7 cm H2O. If a patient had signs of poor tolerance at any time during the t rial, mechanical ventilation was reinstituted. Patients without these features at the end of the trial were extubated. Of the 246 patients a ssigned to the T-tube group, 192 successfully completed the trial and were extubated; 36 of them required reintubation. Of the 238 patients in the group receiving pressure support ventilation, 205 were extubate d and 38 of them required reintubation. The percentage of patients who remained extubated after 48 h was not different between the two group s (63% T-tube, 70% pressure support ventilation, p = 0.14). The percen tage of patients failing the trial was significantly higher when the T -tube was used (22 versus 14%, p = 0.03). Clinical evolution during th e trial was not different in patients reintubated and successfully ext ubated. ICU mortality among reintubated patients was significantly hig her than in successfully extubated patients (27 versus 2.6%, p < 0.001 ). Spontaneous breathing trials with pressure support or T-tube are su itable methods for successful discontinuation of ventilator support in patients without problems to resume spontaneous breathing.