| Abstract [eng] |
Background/objective. Total hip arthroplasty is associated with significant bleeding, which continues through early postoperative hours. Choosing the amount of packed red blood cells (PRBC) for transfusion to reach hematocrit targets is challenging. We compared two methods of predicting post-transfusion hematocrit: the new – Homeostatic Blood States’ Method, patent pending – USA, referred to as method A, and the conventional "Rule of Thumb" (Habibi et al.) referred to as method B. Patients and methods The retrospective investigation of immediate postoperative blood transfusions included sixteen adult patients who were ASA physical status II, five of them males and eleven females, mean age 64.75±10.427 (range, 45–79 yr) after total hip arthroplasty. Patients received routine procedures: venous blood samples taken just before starting transfusion (20 minutes after stopping all infusions), then 20 minutes after transfusion. Eight patients received one PRBC unit, others received two. The amount of wound drainage was measured. Perioperative infusion and transfusion data, timing, blood test results, urine output and drainage amounts were recorded using a new type of chart – HBS Nomogram (Copyright © 2005 by Audrius Andrijauskas). We calculated post-transfusion hematocrit predicted by both methods. Method A deploys mathematical formulas for calculating hematocrit-specific homeostatic circulating erythrocyte mass. Corrections for simultaneous blood loss were applied to calculations by method A protocol A-cor. Corrections are not applicable to method B, which accounts only for units transfused: protocol B1 predicts 3%, B2 4% and B3 5% hematocrit increase. Results. Method B-1 (p = 0.019) predicted hematocrit better than method A, but method A did it better than B-2 (p = 0.04), B-3 (p < 0.0001) and B-1 (p < 0.009), and method A-cor was the best, predicting better than A (p < 0.0001), B-1 (p < 0.009), B-2 (p < 0.0001) and B-3 (p < 0.0001). Method B does not account for simultaneous bleeding, and there are no criteria for choosing a proper protocol – B1, B2 or B3, therefore the overall advantage was given to method A and its modification A-cor. Conclusion: The new method is a promising tool for transfusion amount selection, therefore further investigations are purposeful. |
