Both groups received all other usual care. Regular physiotherapy intervention received by both groups included passive to active-assisted
mobilisation of the limb, chest compression with quick release at end-expiration, aspiration of the endotracheal tube, and positioning. All cardiorespiratory variables (respiratory rate, heart rate, systolic and diastolic blood pressure, and oxyhaemoglobin saturation) were recorded again one minute after the end of the protocol in both groups to identify haemodynamic instability as an adverse event. All patients were followed up until weaning was attempted, unless they died, were tracheostomised, or required controlled ventilation, before completing the weaning process. The primary outcome was the duration of the period of weaning from mechanical ventilation. The hour of the start and the end of this period were recorded. The decision to extubate was the physician’s and was based on the presence of: improvement see more in the aetiology that resulted in respiratory insufficiency, normal radiological evaluation (without pneumothorax, congestion, pleural effusion, or atelectasis), tolerance to pressure support ventilation less than or equal to 14 cmH2O, Navitoclax price haemodynamic stability, no vasoactive drug use (with the exception of dopamine 5 mg/kg/min), pH > 7.25, a partial pressure of oxygen greater than 60 mmHg, a fraction of inspired oxygen less than or equal to 40%, and positive
end-expiratory pressure less than or equal to 8 cmH2O. The protocol for extubation consisted of a spontaneous breathing test via a T-tube for 30 minutes with 5 L/min of Thymidine kinase additional oxygen, during which oxyhaemoglobin saturation was required to remain > 90%. Extubation failure was defined as the participant being returned to mechanical ventilation within 48 hours. The secondary outcomes were inspiratory and expiratory
muscle strength, tidal volume, and the rapid shallow breathing index. Maximal inspiratory and expiratory pressures were measured using a vacuum manometer attached to the endotracheal tube via a connector with a unidirectional valve. The unidirectional valve was applied for 25 seconds before each measurement to guide patients to their residual volume or vital capacity, respectively, in order to obtain the maximal voluntary pressure (Caruso et al 1999). To measure the rapid shallow breathing index, participants were removed from the ventilator and breathed spontaneously in a ventilometer attached to the endotracheal tube for one minute. The rapid shallow breathing index was calculated as the number of breaths per minute divided by the tidal volume in litres (Yang and Tobin 1991). All these measurements were performed before each training session, twice a day. The minimal clinically important difference in the weaning period in this population has not yet been established. We therefore nominated 24 hours as the between-group difference we sought to identify.