A Comparative Study between Continuous Epidural Analgesia versus Ultrasound Guided Continuous Femoral and Sciatic Nerves Block both combined with General Anesthesia for Total Knee Replacement

Abstract

Summary W hen a noxious stimulus produces tissue injury, chemical mediators are released and activate nociceptors which in turn generate nerve impulses. Uncontrolled postoperative pain has an adverse sequel of delayed resumption of normal pulmonary function, restriction of mobility, nausea and vomiting, increase in the systemic vascular resistance, cardiac work, and myocardial oxygen consumption through an increase in the catecholamine release induced by the stress response. Surgeries of the knee are associatedwith moderate to severe postoperative pain, so these procedures are better to be done under regional anesthetic techniques whichreduce neuroendocrinal stress responses, central sensitizationof the nervous system and muscle spasms which occur in responseto painful stimuli. Recently, among these regional anesthetic techniques PNB are gaining popularity because they reduce the possibility of complications and side effects associated with the central blocks. Continuous femoral and sciatic nerves block provides effective analgesia and anesthesia with potentially fewer complications and side effects than epidural blocks. The purpose of this study was tocompare between epidural anesthesia and continuous femoral and sciatic nerves block in adult patients undergoing total knee replacement including comparison of analgesic efficacy, side-effects, and complications. The study was performed upon 60 patients, aging 40-70 years, and randomly distributed among two groups: Group A: 30 patients received lumbar epidural anesthesia followed by general anesthesia. Group B: 30 patients received continuous femoral and sciatic nerves block followed by general anesthesia. For each patient, the following data were collected: age, sex, weight, height, ASA, duration of surgery, hemodynamic changes, incidence of postoperative complications, pain scores, morphine consumption, rehabilitation indices and duration of hospital stay. The results showed that performing continuous femoral and sciatic nerves block provided effective unilateral analgesia, equivalent rehabilitation and duration of hospital stay in addition to fewer complications in comparison to epidural anesthesia such as hypotension, postoperative vomiting and urinary retention.