Chronic obstructive pulmonary disease and weaning of difficult-to-wean patients from mechanical ventilation: randomized prospective study.

Aim: To compare T-tube and pressure support ventilation (PSV) as two methods of mechanical ventilation weaning of patients with chronic obstructive pulmonary disease (COPD) after failed extubation.

Methods: A prospective randomized trial carried out at the multidisciplinary intensive care unit (ICU) over 2 years included 136 patients with COPD who required mechanical ventilation longer than 24 hours. The patients who could be weaned from mechanical ventilation were randomized to either a T-tube or PSV 2-hour spontaneous breathing trial. The patients in whom 2-hour trial was successful were extubated and excluded from further research. Patients in whom 2-hour trial failed had mechanical ventilation reinstated and underwent the same weaning procedure after 24 hours in case they fulfilled the weaning criteria. The weaning outcome was assessed according to the following parameters: extubation success, mechanical ventilation duration, time spent in ICU, reintubation rate, and mortality rate.

Results: Two-hour trial failed in 31 patients in T-tube and 32 patients in PSV group, of whom 17 and 23, respectively, were successfully extubated (P<0.001, chi(2)test). Mechanical ventilation lasted significantly longer in T-tube than in PSV group (187 hours vs 163 hours, respectively, P<0.001, Mann-Whitney test). Also, patients in T-tube group spent significantly more time in ICU than patients in PVS group (241 hours [interquartile range 211-268] vs 210 hours [211-268], respectively, P<0.001, Mann-Whitney test). Reintubation was required in 8 and 6 patients in T-tube and PVS group, respectively, and death occurred in 4 and 2 patients, respectively, during ICU stay.

Conclusion: Patients with COPD who failed the 2-hour spontaneous breathing trial had more favorable outcome when PVS rather than T-tube method was used for weaning from mechanical ventilation.