[Transfusion needs during intraoperative and immediate postoperative periods in arthroplasty of the hip and knee].

OBJECTIVES: To determine the factors associated with immediate perioperative transfusion requirements of hip or knee arthroplasty patients who have not been enrolled in a blood salvage program.

PATIENTS AND METHODS: This prospective study collected demographic (age, sex, weight, height, etc.), physiological (hemoglobin levels, coagulation times, preoperative platelet counts, etc.), clinical history and anesthetic and surgical data (type of anesthesia, surgical diagnosis, duration of procedure) in 112 patients undergoing orthopedic surgery: 19 cases of primary knee arthroplasty, 77 cases of hip arthroplasty and 16 replacements of hip arthroplasty. Logistic regression analysis of the aforementioned variables was performed to search for factors related to transfusional needs during and after hip arthroplasty or after knee arthroplasty, which was performed with a tourniquet applied to render intraoperative transfusion unnecessary.

RESULTS: The variables that increased the risk of transfusion during surgery were duration of procedure exceeding 120 min (OR 15.24; p = 0.01) and loss of over 500 ml of blood during surgery (OR 11.4; p = 0.02). The variables associated with perioperative transfusion were loss of over 500 ml in the postanesthetic recovery room (OR 12.6; p < 0.0001), hypotensive episodes during recovery (OR 11.7; p = 0.0001), prosthetic replacement (OR 6.33; p = 0.005), height < 160 cm (OR 5.03; p = 0.02), preoperative hemoglobin level < 13.5 g/dl (OR 4.97; p = 0.02), and surgery for reasons other than osteoarthritis (arthritis, pathological fractures, etc.) (OR 4.60; p = 0.04). Variables associated with transfusion of over two units of packed red cells were a history of neoplastic disease unrelated to arthroplasty (OR 378.67; p = 0.005), prosthetic replacement (OR 49.71; p = 0.009), diabetes (OR 36.49; p = 0.02) and a hypotensive event while in the postanesthetic recovery room (OR 29.12; p = 0.02).

CONCLUSION: These results suggest that certain modifiable factors increase the risk of blood transfusion in knee and hip arthroplasty. Specifically, they are duration of surgery, intra- and postoperative bleeding, preoperative hemoglobin level and instances of perioperative hypotension. Other factors outside our control are height or patient clinical history.