Risk of infectious complications associated with blood transfusion in elective spinal surgery—a propensity score matched analysis

Background ContextAlthough the negative aspects of blood transfusion are increasingly recognized, less is known about transfusion-related risks in spinal surgery.PurposeThis study was designed to determine whether perioperative allogeneic blood transfusion is associated with increased risk of infectious complications after elective spinal surgery.Study DesignA retrospective cohort study with propensity score matched analysis was carried out.Patient SampleData of patients with spinal canal stenosis and spondylolisthesis who underwent elective lumbar surgeries (decompression or fusion) were obtained from the Diagnosis Procedure Combination database, a nationwide administrative inpatient database in Japan.Outcome MeasuresClinical outcomes included in-hospital death and the occurrence of infectious complications (surgical site infection [SSI], respiratory tract infection, urinary tract infection, and sepsis).MethodsPatients' clinical information, including sex, age, type of hospital, preoperative comorbidities, duration of anesthesia, cell saver use, and volume of allogeneic blood transfused, were investigated. Patients transfused with >840 mL (6 units) were excluded. Propensity scores for receiving transfusion were calculated, with one-to-one matching based on estimated propensity scores to adjust for patients' baseline characteristics. The proportions of complications were compared in patients with and without transfusions. This study was funded by grants from the Ministry of Health, Labour and Welfare, Japan.ResultsOf the 84,650 patients identified, 5,289 patients (6.1%) received transfusions, with 4,436 (5.2%) receiving up to 840 mL. One-to-one propensity score matching resulted in 4,275 pairs with and without transfusion. Patients transfused were at increased risk of SSI (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.4–2.5; p<.001) and urinary tract infection (OR, 2.5; 95% CI, 1.5–4.2; p<.001) than those not transfused.ConclusionsAllogeneic blood transfusion after elective lumbar surgery was associated with increased risks of SSI and urinary tract infection.