Exercise Capacity Impairment Can Predict Postoperative Pulmonary Complications after Liver Transplantation

Abstract

Background: Postoperative respiratory complications (PRCs) are common after liver transplantation (LT) and contribute significantly to the related morbidity and mortality. Objective: The aim of this paper was to determine the incidence of PRCs after LT and the value of simple exercise capacity measures as independent predictors of PRCs. Methods: We conducted a prospective cohort study of consecutive adults submitted to LT at a University Hospital in Fortaleza Brazil from March 2013 to March 2015. At baseline, exercise capacity was assessed with the 6-minute walk test (6MWT) and the 6-minute step test (6MST), lung function was tested by spirometry, and respiratory muscle strength was measured by maximal respiratory pressure. Additional relevant pre- and intraoperative data were collected through interview and chart review, and their association with the incidence of PRCs was evaluated. Results: The study included 100 subjects, 44% of whom presented at least 1 of the PRCs. In the univariate analysis, poor 6MST and 6MWT results and a longer preoperative cold ischemia time were associated with PRCs. The logistic regression analysis showed that PRCs were less likely to occur when preoperative walking distances were longer: the odds ratio (95% CI) was reduced to 0.589 (0.357-0.971) for each 50 m walked (p = 0.03). Likewise, PRCs were more likely to occur in patients with longer preoperative cold ischemia times: the odds ratio (95% CI) increased to 1.008 (1.002-1.015) for each minute (p = 0.01). Conclusion: The incidence of PRCs is high in LT patients. A prolonged cold ischemia time and preoperative 6MWT results were independent predictors of PRCs in this patient population.