Lower tidal volume ventilation post-bilateral lung transplantation is associated with ventilator-free days.

Abstract

There is limited evidence regarding the effect of invasive mechanical ventilation practice post-bilateral lung transplantation. Invasive mechanical ventilation practice may be associated with prolonged ventilation, particularly when referenced to donor anthropometrics. This was a single-centre retrospective cohort study that included consecutive adult bilateral lung transplant recipients between 2015 and 2021 who were ventilated for a minimum of 24 h post-surgery. Lower and higher tidal volume sub-groups were defined for mean and maximum values indexed to both donor and recipient predicted body weight over the first 72 h. The primary outcome was ventilator-free days in the first 28 days, and this was analysed using the Wilcoxon rank sum test and a competing risks regression. We used a Cox proportional hazards model to examine the relationship of ventilator-free days and tidal volume and 90-day survival. The cohort included 111 recipients, and the median ventilator-free days for the entire cohort was 25 (21-26). Lower tidal volume indexed to donor predicted body weight after 48 and 72 h was associated with more ventilator-free days (25 (23-26) vs. 24 (17-26), p = .04 and 24 (21-25) vs. 20 (14-24), p = .02) and increased cumulative incidence of successful extubation (sub-distribution hazard ratio 1.54 (1.07-2.20), p = .02 and SHR 1.87 (1.07-3.27), p = .03). Ventilator-free days and lower tidal volume were associated with increased 90-day survival. Lower tidal volume ventilation indexed to donor predicted body weight is associated with more ventilator-free days post-bilateral lung transplantation. Postoperative ventilation with lower tidal volume indexed to the donor's predicted body weight was associated with more ventilator-free days in patients undergoing bilateral lung transplantation. No difference was found between lower versus higher tidal volume ventilation for other patient-important outcomes. The results highlight the need for larger prospective clinical trials.