HEMODYNAMIC-EFFECTS OF 0.375-PERCENT VERSUS 0.25-PERCENT BUPIVACAINE DURING CERVICAL EPIDURAL-ANESTHESIA FOR HAND SURGERY

Background and Objectives. Cervical epidural anesthesia with 0.375% or 0.25% bupivacaine plus fentanyl is a reliable technique for surgical restoration of digital motion-after tourniquet release and rehabilitat ion. The study was designed to assess the hemodynamic effects of this technique in 11 ASA 1 patients. Methods. The epidural catheter was int roduced at the C7-T1 interspace on the day of operation. The volume of 0.375% bupivacaine necessary to block the brachial dermatomes was det ermined. The day after (day 1), every patient received epidurally the determined volume of 0.375% bupivacaine plus 1 mug/kg fentanyl (group A). On day 2 the same volume of 0.25% bupivacaine plus 1 mug/kg fentan yl (group B) was injected. For each patient one or several pairs of in jection (A + B) were performed in relation with duration of rehabilita tion. Cardiac index, stroke volume index, end diastolic index, ejectio n fraction, and systemic vascular resistance were studied by thoracic electrical bioimpedance. These parameters, mean arterial pressure and heart rate were recorded before and after injection. Sensory level was assessed by loss of cold sensation. Results. Nineteen paired injectio ns were performed. Mean volume of bupivacaine was 7.1 +/- 2 mL. The ca udad sensory level was lower in group A: T7 (T3-L1) versus T6 (T2-T11) in group B. Hemodynamic variables were not different between the 2 gr oups. Mean arterial pressure cardiac index, heart rate, stroke volume index, and ejection fracture decreased slightly as end diastolic index remained unchanged and systemic vascular resistance increased slightl y. No correlation was found between hemodynamic changes and spread of analgesia. Conclusions. Hemodynamic effects, in ASA 1 patients, are mo derate and not dependent on the studied concentration of bupivacaine, indicating that a similar degree of sympathetic block is achieved with 0.375% and 0.25% bupivacaine.