BACKGROUND: Anemia is common in patients presenting for elective surgery and is associated with increased risk of perioperative blood transfusion, and consequential morbidity and mortality. In addition to its direct contribution to morbidity, blood transfusion also burdens the health system financially in terms of both direct (acquisition, inventory, verification) and indirect (increased length of stay, transfusion related events) costs. When preoperative anemia is treated, reduced cost of care with improved quality of outcomes has been demonstrated. The Preoperative Anemia clinic (PAC) at Duke University Hospital was launched to medically optimize patients who require care that carries a high risk of transfusion. We aim to present the results of the first year of this project to optimize patients presenting for elective hip and knee arthroplasty.
METHODS: Following IRB review, we performed a retrospective review of all adult patients undergoing primary and revision hip and knee arthroplasty at a single institution referred to the PAC in the first year following its launch. These patients were compared to a historical cohort of patients prior to the PAC launch that would have met criteria for referral based on their preoperative hemoglobin value. Preoperative hemoglobin, age, sex, procedure, estimated blood loss (EBL), intraoperative packed red blood cell (RBC) transfusion and use of intraoperative tranexamic acid (TXA) were assessed for both groups by chart review. Microsoft Excel was used to calculate statistical values, presented as mean +/- standard deviation or percent of cohort.
RESULTS: Out of 200 patient records in the historical cohort, 21 were identified as “at risk” by current referral standards. In the first year of the PAC, 36 patients were referred to the PAC, 14 of whom completed treatment and subsequently went on to have surgery. Among treated patients, hemoglobin increased from 10.4g/dL ± 0.81 to 12.5g/dL ± 1.57 (p=0.00351). Intraoperatively no statistically significant difference was found in EBL between treated and historic patients (283mL ± 374 vs 364mL ± 265). The intraoperative use of TXA was higher among the patients referred to the PAC vs historic patients (78.6% vs 33.3%, p=0.0087). Patients in the treated group (i.e. preoperative iron and/or erythropoietin infusion with or without TXA) had a reduced incidence of RBC transfusion compared to non-treated patients (14.3% vs 66.7%, p =0.0023). Relative risk of transfusion for treated patients compared to historic patients was reduced at 0.21 [95% CI 0.06-0.80].
DISCUSSION: Patients who underwent treatment through PAC demonstrate a statistically significant increase in hemoglobin. Furthermore a transfusion reduction was observed in preoperative optimized and intraoperative treated patients compared to a historic cohort. These findings may be attributable to an increase in pre-op hemoglobin, intraoperative TXA use, or both.
