GSTM1 and infection: In the univariate analysis, age, preoperative cerebrovascular comorbidities, preoperative cardiovascular comorbidities, intraoperative RBC transfusion, postoperative RBC transfusion, postoperative colloid infusion, albumin infusion, PCA, diuretics, vasopressor use, postoperative complications of infection, obstruction, and hemorrhage, and preoperative laboratory tests for Hb, Alb, BUN, SCr, and glucose (Glu) were identified as risk factors.