Abstract
Introduction
The injurious effects of large tidal volumes during mechanical ventilation in ARDS are well established, but the impact and determinants of injurious ventilation in lung transplantation are unknown.
Methods
124 bilateral lung transplants between June 2010 and April 2013 were reviewed. Patients were retrospectively assigned to high (≥25cm H2O) and low pressure (<25cm H2O) groups based on the average inflation pressures used in the first 6 hours after surgery. Average tidal volumes and lung compliance were also recorded. The median values [with interquartile ranges] for ICU length of stay (LOS) and lung function (% predicted FEV1 at 3 months) were documented for each group. The 6 month survival rate was also recorded.
Results
The low-pressure group (n=76) had a LOS of 5 days [4-19], FEV1 of 79.2% [62.7-92.6] and 6 month survival rate of 95%. The high-pressure group (n=48) had a prolonged LOS of 12 days ([4-36], p=0.012), a lower FEV1 at 61.4% ([51.3-67.0], p<0.001), and lower survival rate of 77% (p=0.008). Lung compliance was higher in the low pressure group (34ml/cmH2O, [28-39]) than the high pressure group (24ml/cmH2O, [20-27], p<0.001). Outcomes were associated with inflation pressures and lung compliance, but not with tidal volumes.
Discussion
Reduced lung compliance and mechanical ventilation with high inflation pressures in the first hours following lung transplantation are significantly associated with poorer outcomes for months after surgery. This may reflect early lung injury necessitating the use of higher inflation pressures. Alternatively, ventilation with higher inflation pressures might have inflicted lung injury that adversely affected clinical outcomes.
- © 2014 ERS