PERIOPERATIVE CHANGES IN CARDIAC AUTONOMIC CONTROL IN PATIENTS RECEIVING EITHER GENERAL OR LOCAL-ANESTHESIA FOR OPHTHALMIC SURGERY

To investigate whether local (LA) or general anesthesia (GA) provides more perioperative stability in cardiac autonomic tone, we analyzed he art rate variability (HRV) by means of spectral analysis, intraoperati vely and up to 3 h postoperatively, in otherwise healthy patients sche duled for cataract surgery. Fourteen patients received GA (premedicati on: clorazepate; anesthetic induction: propofol, alfentanil, atracuriu m; anesthetic maintainance: isoflurane, alfentanil; airway management: laryngeal mask airway), and 14 patients received LA (retrobulbar bloc k with bupivacaine/mepivacaine). In the GA group, total power, as an i ndicator of cardiac autonomic activity, was significantly reduced intr aoperatively and increased slowly during the postoperative period. The ratio of low frequency/high frequency (LF/HF) power, indicating cardi ac sympathovagal balance, did not change significantly intraoperativel y and remained stable in the postoperative period. The LA group showed no significant changes in total power intraoperatively. Postoperative ly, heart rate and the LF/HF power ratio were significantly increased in the LA group compared to the GA group. GA as described above was as sociated with intra- or postoperative stability of the cardiac sympath ovagal balance. Thus GA had no disadvantageous effects on the perioper ative cardiac autonomic tone during ophthalmic surgical procedures com pared to LA in otherwise healthy patients.