Randomized Trial of Protective Lung Ventilation in Organ Donors

Abstract

<h3>Purpose</h3> A protective ventilation strategy that targeted lower tidal volume (TV) and higher positive end expiratory pressure (PEEP) improved lung utilization in European donors but has not been tested in a US donor population. We conducted a randomized trial of an open lung protective ventilator (OLPV) strategy with lower TV, higher PEEP and protocolized recruitment maneuvers (RM) compared to a conventional ventilator (CV) strategy with higher TV and lower PEEP in deceased donors in Northern California. The primary outcome was donor lung utilization for transplantation. <h3>Methods</h3> Donors were eligible for inclusion if greater than 13 years of age and PaO₂/FiO₂ was between 150 and 400. Eligible donors were randomized to volume control ventilation with OLPV [TV 6 ml/kg predicted body weight (PBW), PEEP 10, protocolized RM] or CV [TV 10ml/kg PBW, PEEP 5, RM only after vent disconnect] for the duration of donor management. Lungs were evaluated for transplant potential on standard ventilator settings in both arms [TV 10ml/kg PBW, PEEP 5, FiO₂ 1.0]. <h3>Results</h3> Between July 2018 and December 2019, 153 donors were randomized (74 to OLPV, 79 to CV) and included in the final analysis. The trial stopped early due to changes in donor management at the participating OPO. Donor demographics were similar by treatment arm and compliance with the ventilator protocols was excellent. Median duration of treatment was 49.5 hours and did not differ by arm. Among 153 donors, 33 became lung donors, 16/74 (21.6%) in the OLPV arm and 17/79 (21.5%) in the CV arm, P = 0.99. Change in donor oxygenation as measured by PaO₂/FiO₂ from enrollment to procurement did not differ by treatment arm; median change (IQR) in OLPV versus CV was 53 (-5 to 139) vs 46 (-77 to 117), P = 0.14. Change in static compliance of the respiratory system also did not differ by treatment arm. There was no difference in need for vasopressors between arms. One serious adverse event that was possibly related to the study intervention occurred in the CV arm with expansion of a pneumothorax requiring chest tube placement. Among 29 lung recipients in whom detailed data were available, duration of mechanical ventilation, ICU stay and hospital stay did not differ by donor treatment arm. <h3>Conclusion</h3> An open lung protective ventilator strategy was safe but did not improve donor lung utilization or oxygenation compared to a conventional ventilator strategy in a population of US organ donors. Funding: NIH HL126176