The impact of intraoperative and anesthetic factors on early post lung transplant outcomes

David McIlroy, David Pilcher, Greg Snell

Alfred Hospital

Background: Primary Graft Dysfunction (PGD) is a major cause of early morbidity and mortality after lung transplantation. While a substantial amount of work has been done to understand the risk factors for PGD in terms of donor, recipient and surgical factors, little is understood regarding the role of anaesthetic and intraoperative variables in its development.

Methods: We conducted a retrospective cohort study of 107 consecutive lung transplants. We analysed both the PaO2/FiO2 ratio and the proportion of patients with grade 3 PGD up to 72 hours postoperatively to determine the time-point which had the strongest association with the clinical endpoints of time to extubation and ICU length of stay. Using univariate and multivariate regression analysis we then explored the association between intraoperative and anaesthetic variables, and both the PaO2/FiO2 ratio and prevalence of grade 3 PGD, at the selected time-points.

Results: The PaO2/FiO2 ratio at 12 hours post transplantation and the presence of Grade 3 PGD at any time between 6-72 hours postoperatively were identified for further analysis. Increasing volume of intraoperative colloid was independently associated with a lower PaO2/FiO2 ratio at 12 hours (β-coefficient -44mmHg, 95% C.I. -7 to -81 mmHg, p=0.02) while epidural block was strongly associated with a reduced rate of grade 3 PGD up to 72 hours postoperatively (O.R. 0.06, 95% C.I. 0.01 - 0.66, p=0.02).

Conclusions: We have demonstrated an inverse association between volume of intraoperative colloid with early lung allograft function, and epidural block with the development of grade 3 PGD. Both these associations persist despite adjusting for potential confounding variables. These key perioperative factors should be evaluated in prospective randomized studies.