Higher Hb level is associated with better early functional recovery after hip fracture repair

BACKGROUND: The benefits and indications for blood transfusion are controversial. One possible reason to transfuse is to improve functional recovery after major surgery. However, the data linking improved function with higher Hb concentration are limited. STUDY DESIGN AND METHODS: A retrospective cohort study was performed in 5793 patients at least 60 years old undergoing hip fracture repair at 20 academic and community hospitals. The primary outcome was distance walked at the time of discharge from the hospital. The mean postoperative Hb concentration was the main exposure variable and was defined as the average value from Day 1 after surgery to discharge. We used robust regression to assess the association between postoperative Hb level with distance walked, controlling for other preoperative variables that could influence functional recovery. RESULTS: On bivariate analysis, the predicted distance walked at discharge in feet (95% CI) increased with higher Hb levels (7 g/dL, 56 feet [42-70]; 8 g/dL, 61 feet [54-68]; 9 g/dL, 67 feet [64-70]; 10 g/dL, 74 feet [72-77]; 11 g/dL, 83 feet [80-85]; 12 g/dL, 92 feet [87-96]). After adjustment for other factors associated with ability to walk, higher average postoperative Hb level was independently associated with walking greater distance (p < 0.001). CONCLUSIONS: Higher postoperative Hb level may improve functional recovery after hip fracture repair. If confirmed with clinical trials, this finding would provide a rationale to maintain higher Hb concentrations in elderly patients recovering from surgery.