[Low-dose aspirin doesn't increase surgical bleeding nor transfusion rate in total knee arthroplasty]. / El tratamiento preoperatorio con aspirina a dosis bajas no aumenta la hemorragia quirúrgica ni la tasa transfusional en la prótesis total de rodilla.

OBJECTIVES: Surgical bleeding. transfusion rate and cardiovascular complications were analized in patients undergoing chronic treatment with low-doses aspirin and scheduled to unilateral primary knee arthroplasty. PATIENTS AND METHODS: We retrospectively studied 117 patients between 2005 and 2006 scheduled for elective knee replacement that received antiplatelet therapy with aspirin (100mg/day). Aspirin medication was maintained or discontinued preoperatively according to medical criteria. We analyzed the biological, clinical and anesthetic data, blood-saving techniques used, surgical bleeding, allogeneic blood transfusion rate, cardiocirculatory complications (myocardial, cerebral or peripheral ischemia), hospital stay and mortality. This population was compared with 190 patients (control group) who underwent the same operation at the same time interval but did not receive aspirin therapy. RESULTS: The aspirin-treated group was significantly older, with higher weight and poorer health state (higher incidence of ischemic heart disease, cerebral ischemia and diabetes). The hidden and external surgical bleeding and transfusion rate were similar if the aspirin were interrupted or not, preoperatively. Bleeding and transfusion rates were independent of time of interruption of the aspirin. Hospital mortality was zero in the 2 groups. A acute myocardial infarction and a transient stroke happened in two patients wich aspirin treatment was discontinued. CONCLUSIONS: Preoperative treatment with low doses of aspirin does not increase surgical bleeding and transfusion rate in total knee arthroplasty. Preoperative discontinuation can cause severe cardiocirculatory complications.

[Epidural analgesia versus femoral or femoral-sciatic nerve block after total knee replacement: comparison of efficacy and safety]. / Comparación de la eficacia y seguridad de tres técnicas analgésicas (epidural, bloqueo femoral y bloqueo femoral-ciático) en el postoperatorio de prótesis total de rodilla.

OBJECTIVE: Pain after total knee replacement surgery is intense. The aim of this study was to compare 3 techniques for providing postoperative analgesia (epidural analgesia, femoral nerve block, and a combined femoral-sciatic nerve block) in total knee arthroplasty. MATERIAL AND METHODS: Observational study of 1550 elective primary unilateral total knee replacement operations. The safety and efficacy of the following 3 techniques were compared: epidural analgesia, femoral nerve block, and femoral-sciatic nerve block. Demographic, anesthetic, and surgical data were recorded. Study variables included pain intensity on a visual analog scale every 4 hours, need for rescue analgesia (morphine), complications and adverse events within 5 postoperative days. RESULTS: No significant differences were found in demographic, anesthetic, or surgical variables. In the first 24 hours after surgery, pain intensity was significantly less for patients who received a femoral-sciatic nerve block. The mean levels of morphine consumption in the first 96 hours after surgery were similar in the femoral-sciatic nerve block group (3.18 mg) and the epidural analgesia group (3.19 mg); morphine consumption in the femoral block group was significantly higher (4.51 mg). Epidural analgesia was associated with the highest rate of complications (17%). CONCLUSIONS: A sciatic nerve block combined with a femoral nerve block attenuates pain more effectively and is associated with less postoperative morphine consumption in comparison with a femoral nerve block alone. Peripheral nerve block techniques have fewer adverse side effects than epidural analgesia.