C. Keyl et al., PERIOPERATIVE CHANGES IN CARDIAC AUTONOMIC CONTROL IN PATIENTS RECEIVING EITHER GENERAL OR LOCAL-ANESTHESIA FOR OPHTHALMIC SURGERY, Anesthesia and analgesia, 82(1), 1996, pp. 113-118
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.