Weaning from mechanically ventilation is a period of transition from total ventilatory support to spontaneous breathing. The aim of this study was to compare the effects of T-Piece and continuous positive airway pressure (CPAP) on hemodynamic parameters, arterial blood gases and success of weaning. In a prospective, randomized, controlled trial, 40 consecutive patients requiring mechanically ventilation in our 8-bed adult general intensive care unit (ICU) for > 48 hrs were considered eligible for this study. Patients were randomly divided into two groups (n: 20). Group T-piece received, 4 L/min, Group CPAP received, PEEP cm H(2)O, FiO(2) <= 0.4. At the beginning of the weaning, duration of extubation and after 48 hours of extubation the arterial blood samples were taken for blood gases analysis, also the mean arterial pressure and heart rate were recorded. 40 patients in the ICU were included in the study. There were no significant differences within and between T-piece and CPAP groups according to hemodynamic parameters and arterial blood gases at the weaning period. The number of patients who could be unsuccessful weaned in the T-piece group was higher than the number of patients in the group CPAP (p<0.001, p<0.01). Whether, the technique used to wean patients, in this setting, resulted in a clinically relevant improvement in the outcomes addressed above requires further carefully designed, randomized, controlled trials (Tab. 4, Ref. 25). Full Text in free PDF www.bmj.sk.