Combined Femoral and Sciatic Blocks Versus Epidural Anesthesia in Infrainguinal Surgeries, Hemodynamic Stability and Myocardial Morbidity, TAMER I. ROUK and TAMER M. KHEIR
Abstract
Background: Infrainguinal surgeries for patients with peripheral vascular disease are often risky due to the nature of the surgical procedure, the associated co-morbidities (dia-betes mellitus, hypertension and ischemic heart disease), and the need for efficient post-operative analgesia. Infrainguinal procedures included femoral, popliteal and infra-popliteal vascular bypass surgeries, thrombectomies, embolectomies and endarterectomies. Lower limb amputations (due to more critical ischemia or failed bypass) as well as varicose veins may be added. Using a combination of a sciatic nerve block with a femoral nerve block in these patients is a good anesthetic technique in contrary to the conventional neuraxial (spinal or epidural) anesthesia, which may be a contraindication in anti-coagulated patients, septic shock and cardiovascular compro-mise; again spinal/epidural anesthesia usually causes evident hypotension.
Aim of Work: Assessment of significance of hypotension and associated cardiac morbidity in both anesthetic techniques in this critical group of patients.
Patients and Methods: We prospectively randomized 80 patients, undergoing unilateral infrainguinal surgeries, to receive either single shot combined femoral and sciatic nerve blocks or lumbar epidural anesthesia. Combined femoral sciatic block group (n=40) received isobaric bupivacaine 0.375% (femoral 20ml and sciatic 20ml) with nerve stimulator guidance. While epidural group (n=40) received isobaric bupivacaine 0.375% using loss of resistance to air technique for space detection then 5-mL aliquots were given to attain a sensory level at T10 which is adequate for surgery. Pre-operative set of cardiac biomarkers (CK, CK-MB and LDH) and ECG was obtained, intra-operative blood pressure, heart rate, dysrhythmias and any chest pain or dyspnea were ob-served. Post operatively, patients were observed for compli-cations and need for ICU admission, and another set of cardiac biomarkers and ECG were repeated 24 hours later.
Results: Significant blood pressure stability was observed in femoral-sciatic group, heart rate showed no difference. A significant smaller drop in cardiac biomarkers was found in epidural group (when compared with femoral-sciatic group) but with no clinical symptoms or ECG changes. Only one case of ST segment depression with no clinical impact was found.
Conclusion: The use of combined femoral-sciatic nerve block is superior in hemodynamic stability to conventional epidural analgesia in patients undergoing unilateral Infrain-guinal surgeries. However, cardiac morbidity was clinically the same, and with no difference in the incidence of compli-cations.