Association between anesthesiologist experience and mortality after orthotopic liver transplantation

Abstract

The anesthesiologist has been recognized as an integral member of the liver transplant team, and previous studies have demonstrated that inter-anesthesiologist variability can be a driver of outcomes for high-risk patients. We hypothesized that anesthesiologist experience, defined as the number of previous liver transplants performed at our institution, the Icahn School of Medicine at Mount Sinai, would be independently associated with outcomes for liver transplant patients. Eight hundred forty-nine liver transplants performed between January 2003 and January 2013 with a total of 22 anesthesiologists were analyzed. Each transplant was assigned an incremental case number that corresponded to the number of transplants that the attending anesthesiologist had already performed at our institution. Several perioperative covariates were controlled for in the context of a generalized linear mixed effects model to detail the influence of threshold levels of the incremental case number on the primary outcome, 30-day mortality, and a secondary outcome, 30-day graft failure. Sensitivity analyses were conducted to confirm the robustness of these findings. An incremental case number - 5 was associated with a significantly greater risk of 30-day mortality (odds ratio 5 2.24, 95% confidence interval 5 1.11-4.54, P 5 0.025), and there was evidence suggestive of a greater risk of 30-day graft failure (odds ratio 5 1.93, 95% confidence interval 5 0.95-3.93, P 5 0.071). Sensitivity analyses ruled out threats to the validity of these findings, including dropout effects and time trends in the overall performance of the transplantation unit. In conclusion, this study shows that an anesthesiologist's level of experience has a significant effect on outcomes for liver transplant recipients, with increased mortality and possibly graft failure during a provider's first 5 cases. These findings may indicate the need for increased training and supervision for anesthesiologists joining the liver transplant team.