BLOOD TRANSFUSION-SPARING PLAN IN PRIMARY TOTAL KNEE ARTHROPLASTY

Abstract

Introduction: A prospective analysis of the total blood losses (TBL) and the rate of blood transfusions was conducted for the unilateral primary TKA performed at our clinic from January 2008 to March 2009. A transfusion-sparing strategy was used, based on the use of the tourniquet, the intraoperative injection of tranexamic acid and the preoperative administration of erythropoietin for patients with hemoglobin baseline level less than 13 gr/dl. The formula of Gross and the values of Gilcher were utilized to calculate TBL and to estimate the blood volume of the patient.

No autologous blood transfusion systems were employed. The postoperative program consisted of pain control and anticoagulants. Results were compared with a historical cohort of patients operated on with the aid of cell salvage.

Materials and Methods: One hundred – five patients (mean age, 73 years) were admitted to the study group and compared to an historic group including 44 patients (mean age, 70 years).

No significant differences were found between the study arms regarding BMI (31 kg/m2), ASA score and operating time (65 minutes).

Results: Mean TBL was 1560 ml versus 1821 ml in the historic group throughout the entire 8-day period. In the study group, TBL was significantly reduced in the patients who received tranexamic acid. In both groups, one patient received homologous blood transfusion. In the historic group, 41 of the 44 patients received autologous blood transfusion from reinfusion drains (mean volume 314 ml). Finally, the mean Hb at postoperative day 8 (POD 8) was 10,95 g/dl in the study group versus 10,35 gr/dl in the historic group (p< 0.01). Costs were superior in the study group in relation to the use of erythropoietin. No complications were related to the use of the blood –sparing pharmacologic agents.

Discussion: This study confirms that recent improvements in surgical and anesthetic procedure allow for performing routine unilateral TKA with a marginal rate of blood transfusion when the procedure is achieved by an experienced team using a blood-conserving strategy. The strengths of this study include the calculation of blood loss and the homogeneity between the study arms. However the reduction of TBL related to the use of tranexamic acid was not evaluated within the setting of a randomized clinical trial. Furthermore, the results were obtained in patients having a high BMI.

Conclusion: The blood transfusion sparing plan improved quality of care by reducing the risks of transfusion and maintaining a satisfactory Hb level at POD 8