Association of preoperative thyroid hormone replacement with perioperative complications after major abdominal surgery

Objective: To determine the association between preoperative thyroid hormone replacement and complications following major abdominal surgery. Methods: A retrospective case series was performed of patients enrolled in the Michigan Surgical Quality Collaborative (MSQC) who underwent major abdominal surgery at an academic institution over a 10 -year period. The principal explanatory variable was preoperative thyroid hormone replacement. Primary outcomes were morbidity, mortality and length of stay. Results: 2700 patients were identi fied. On multivariate analysis correcting for established predictors of operative morbidity, patients on preoperative thyroid replacement had a 1.5- fold increased risk of serious morbidity(p = 0.01), and a 1.7- fold greater risk for serious sepsis(p = 0.04). Thyroid replacement was associated with longer length of stay(p < 0.001). While there was a high degree of missing data for surgical approach (31.1 % missing data), results suggest that patients on thyroid hormone replacement were more likely to undergo an open rather than minimally invasive surgery(p < 0.01). Open surgery was associated with greater risk of serious morbidity(p = 0.003) and longer length of stay(p < 0.001). Conclusions: Preoperative thyroid hormone replacement independently predicts operative morbidity and length of stay following major abdominal surgery.