The Effect of Varying Preoperative Hemoglobin Levels on the Risk of Major Complications and Surgical Site Infections After Single Level Lumbar Fusion.

Abstract

Blood transfusions are associated with an increased risk of complications after lumbar fusion, and current anemia hemoglobin thresholds are not surgery specific. We aimed to calculate single-level lumbar fusion-specific preoperative hemoglobin strata that observe the likelihood of 90-day transfusion and evaluate whether these strata are associated with increased risk of 90-day complications and 2-year infections. A national database identified patients undergoing primary single-level lumbar fusion with preoperative hemoglobin values (g/dL). Stratum-specific likelihood ratio analysis calculated sex-based hemoglobin strata associated with the risk of 90-day transfusion. Incidence and risk of 90-day major complications and 2-year infections were observed between strata. Three female (hemoglobin strata, likelihood ratio [<10.9, 2.41; 11.0 to 12.4, 1.35; 12.5 to 17.0, 0.78]) and male (<11.9, 2.95; 12.0 to 13.4, 1.46; 13.5 to 13.9, 0.71) strata were associated with varying likelihood of 90-day blood transfusion. Increased 90-day complication risk was associated with two female strata (hemoglobin strata, relative risk [11.0 to 12.4, 1.52; <10.9, 3.40]) and one male stratum (<11.9, 2.02). Increased 2-year infection risk was associated with one female (<10.9, 3.67) and male stratum (<11.9, 2.11). Stratum-specific likelihood ratio analysis established sex-based single-level lumbar fusion-specific hemoglobin strata that observe the likelihood of 90-day transfusion and the risk of 90-day major complications and 2-year infections. These thresholds are a unique addition to the literature and can assist in counseling patients on their postoperative risk profile and in preoperative patient optimization. Level III.