Other investigators, who remained blinded to treatment allocations, measured maximal inspiratory and expiratory pressures and the rapid shallow breathing

index twice a day until the end of the weaning period. The weaning period was defined as from the end of controlled ventilation (ie, the commencement of pressure-support ventilation) until extubation. A daily awakening trial with a minimum level of sedation identified which patients would be transitioned from controlled BEZ235 mechanical ventilation to pressure-support ventilation. The time of extubation was decided by the treating physicians, who were blinded to the treatment allocations. Patients were included in this study if they were aged 18 years or more, had undergone mechanical ventilation for more than 48 hours in a controlled mode, and were considered ready for weaning with pressure-support ventilation between 12 cmH2O and 15 cmH2O and positive end-expiratory pressure between 5 cmH2O and 7 cmH2O. They had to be haemodynamically stable without the aid of vasoactive drugs (dopamine, dobutamine or norepinephrine) or sedative agents. This study excluded patients with hypotension (systolic blood pressure < 100 mmHg or mean blood pressure < 70 mmHg), severe intracranial disease with inadequate consciousness level

(Glasgow Coma Scale ≤11), barotrauma, tracheostomy, or neuromuscular disease. In the experimental group, inspiratory muscle training began when the participants were changed from controlled to pressure-support ventilation. The patients were selleck screening library ventilated using one of three mechanical ventilatorsa. Before each training session, the patients were positioned in 45-deg Fowler’s position and cardiorespiratory variables (respiratory rate, heart rate, systolic and diastolic blood pressures, and oxyhaemoglobin saturation) were recorded to ensure that participants did not undertake training if they were haemodynamically unstable, defined as: respiratory Astemizole rate > 30 breaths/min, oxyhaemoglobin saturation < 90%, systolic blood pressure > 180 mmHg or < 90 mmHg, paradoxical breathing, agitation,

tachycardia, haemoptysis, arrhythmia, or diaphoresis (Caruso et al 2005). The pressure of the endotracheal tube cuff was maintained at 30 mmHg during the training session (Lewis et al 1978). The experimental group was trained using an inspiratory threshold deviceb with a load equal to 40% of the participant’s maximal inspiratory pressure. Each training session consisted of 5 sets with 10 breaths, twice a day, seven days a week. Supplementary oxygen was added if necessary during a training session (Martin et al 2002). The training session was interrupted in the presence of haemodynamic instability, as defined above. In the event of haemodynamic instability, the participant was returned to pressure-support ventilation.