Rationalized preoperative management of hip and knee arthroplasty patients: A retrospective cohort study

Abstract

BackgroundCurrent practices prioritize transfusion readiness over preoperative hemoglobin (Hgb) optimization in elective arthroplasty patients. We characterized the relationship between preoperative Hgb and perioperative transfusion among patients undergoing primary hip and knee replacement in order to identify a threshold Hgb at which the probability of transfusion is negligibly low. We then evaluated an alternative preoperative patient management algorithm using an evidence-guided threshold for pre-transfusion testing. MethodsWe performed a retrospective cohort study of adults undergoing elective primary hip or knee arthroplasty at two academic hospitals between 2010 and 2017. A subset of patients received either no treatment, iron supplementation, or erythropoietin preoperatively. Logistic regressions modelled the likelihood of transfusion, adjusted for baseline covariates. Receiver operating characteristic plots were generated to determine which Hgb threshold best predicted transfusion. Our results informed a quality-improvement initiative involving revised preoperative clinical pathway. ResultsWe included 13,113 patients. A 10 g/L lower Hgb corresponded to 2.81 (95%CI: 2.43–3.25; p < 0.001) and 2.34 (95%CI: 1.95–2.82; p < 0.001) times higher likelihood among hip and knee arthroplasty patients, respectively. A Hgb ≤115 g/L yielded negative predictive values of 98% and 99% for predicting transfusion in hip and knee patients, respectively. A subsequent quality-improvement initiative decreased unnecessary pretransfusion testing by 82%, and was associated with cost-savings. ConclusionsOur results demonstrate that, at our center, a preoperative Hgb ≤115 g/L distinguishes between joint arthroplasty patients who require transfusion from those who do not. Patient-guided pretransfusion testing may streamline joint arthroplasty program efficiency.