A prospective, randomized trial was performed in a multidisciplinary Intensive Care Unit (ICU) for the duration of 2 years. A total of 136 COPD patients who required mechanical ventilation longer than 24 h fulfilled the inclusion criteria and they present the research sample. After fulfilling the criteria for weaning, patients were randomized to a 2-h spontaneous breathing trial with either T-tube or pressure support ventilation (PSV). The patients with successful 2-h trial were extubated and were excluded from further research. Patients with 2-h trial failure were defined as difficult to wean, they had mechanical ventilation reinstated and the same weaning procedure was repeated after 24 h, if the patient again fulfilled the weaning criteria. In these patients, two methods of weaning were compared according to the patients clinical characteristics, objective parameters and procedure outcome.

31 (47%) patient with T-tube and 32 (46%) patients with PSV had 2-h trial failure. Of those patients, successful extubation was in 17 (56%) patients with T-tube and in 23 (72%) with PSV (P <0.001), whereas extubation failure was in 14 (44%) patients with T-tube and in 9 (28%) patients with PSV (P <0.001). Mechanical ventilation duration was 186.7 h with T-tube and 163.2 h with PSV (P <0.001), time spent in ICU was 240.7 h with T-tube and 210.2 h with PSV (P <0.001).

In patients with COPD who failed the 2-h spontaneous breathing trial, based on parameters of procedure outcome, high advantage of PSV method was confirmed.