A comparison of high vs standard tidal volumes in ventilator weaning for individuals with sub-acute spinal cord injuries: a site-specific randomized clinical trial

Study design:Prospective, randomized, controlled parallel group trial with single-blinded data analysis.Objectives:To determine the safety and efficacy of higher (20 ml kg−1ideal body weight (IBW)) vs standard (10 ml kg−1IBW) tidal volumes (Vt) for patients with sub-acute traumatic tetraplegia during ventilator weaning using a 14-day (minimum) weaning protocol.Setting:United States regional spinal cord injury treatment center.Methods:Thirty-three ventilator requiring inpatients were randomized to either the higher (Group 1) or the standard (Group 2) Vt protocol. Initially, all patients were ventilated at 10 ml kg−1IBW Vt and 5 cm H2O of PEEP for 72 h. For Group 1, Vt was raised 100 ml kg−1until reaching target Vt of 20 ml kg−1IBW. Group 2 was maintained at Vt of 10 ml kg−1IBW. Plateau pressures were kept at or below 30 cm H2O. Safety outcomes included incidence of adverse events.Results:Because of smaller than expected enrollment, evaluation of efficacy was not possible. Therefore, we report the safety outcomes of 33 study participants. The 16 patients in Group 1 and 17 patients in Group 2 were demographically similar at baseline, except for age. The average age was 39.3 years in Group 1 and 27.2 years in Group 2, (P=0.002). There was no difference in median days to wean: 14.5 days in Group 1 and 14 days in Group 2. The incidence of adverse pulmonary events was similar between groups.Conclusion:Higher tidal volumes can be safely utilized during weaning of patients with tetraplegia from mechanical ventilation using a 14-day weaning protocol.