PURPOSE: To determine safety and efficacy of high(20ml/kg IBW ) vs standard(10ml/Kg IBW) tidal volumes (Vt) in patients with traumatic tetraplegia. Practice guidelines suggest using higher Vts to prevent atelectasis, improve compliance and increase wean rates but benefit and risks have not been established.
METHODS: Sample: Ventilator-dependent patients with C3-C6 tetraplegia ≥ 2 weeks post injury. Setting: Regional spinal cord injury rehabilitation center. Design: Prospective, single center, randomized, controlled parallel group trial with single blinded data analysis. Primary exclusion: Acute lung injury or ventilator associated pneumonia (VAP). Interventions: All patients received 10ml/Kg Vt for 72hours prior to randomization to either high or standard tidal volumes in assist control mode on 5PEEP. Vt was raised 100ml/day until goal Vt achieved. Plateau pressures were kept ≦30mmHg. Primary outcome measures: Time to wean from mechanical ventilation. Secondary endpoints: Incidence of VAPs, atelectasis, ARDS and barotrauma. Duration: 8 weeks.
RESULTS: 16 patients were randomized to high Vt (group 1) and 17 patients to standard Vt (group 2). The average age was 39.3 in group 1 vs 27.2 in group 2(p=0.002). The pre-wean FVC was not different between groups (1230ml vs 1122ml) (p=0.541). The days on mechanical ventilation prior to weaning was 37.8 in group 1 vs 28.4 in group 2.(p=0.197). There was no difference in the median days to wean from ventilation(14.5 vs 14days);(p=0.687). There were 4 VAPs in group 1 and 3 in group 2.(OR 0.643;p=0.607) There was no episodes of ARDS or barotrauma in either group. The incidence of adverse events was equal in both groups.
CONCLUSIONS: There was no significant difference in time to wean, incidence of VAP, or occurrence of adverse events in tetraplegic patients ventilated at 10ml/kgVt vs 20ml/kg Vt. Importantly, mechanical ventilation at higher tidal volumes was not associated with any episode of ARDS or barotrauma.
CLINICAL IMPLICATIONS: If administered in a controlled fashion,subacute tetraplegic patients without acute lung injury can be safely managed with higher ventilator tidal volumes.
DISCLOSURE: The following authors have nothing to disclose: James Fenton, Mary Warner, Susan Charlifue, Daniel Lammertse, Amy Dannels-McClure, Martinez Lonnie, Matthew Fleishman, Kelly Mowrey, Cate McGraw
The procedures/techniques described in the presentation are considered research.