EPIDURAL-ANESTHESIA AND ANALGESIA DO NOT AFFECT ENERGY-EXPENDITURE AFTER MAJOR ABDOMINAL-SURGERY

Our objective was to determine the effect of perioperative epidural an aesthesia and analgesia on the increase in energy expenditure which ac companies major elective abdominal surgery in a prospective, randomize d study. Eight patients undergoing elective resections of the colon an d/or rectum received general anaesthesia alone (nitrous oxide, oxygen, and isoflurane, supplemented with intravenous fentanyl to a maximum o f 10 mug . kg-1), and 12 patients received perioperative epidural anae sthesia and analgesia using lidocaine (carbonated lidocaine 2% with ep inephrine 1:200,000, 20 ml over 30 min) and morphine (preservative-fre e morphine 0. 10 mg . kg-1 after catheter insertion and 0.05 to 0.10 m g . kg-1 every 12 hr as needed until the morning following surgery) vi a a lower lumbar catheter in addition to general anaesthesia. Respirat ory gas exchange was measured using a metabolic cart and canopy system early on the morning of surgery, six hours postoperatively, and on th e first and second postoperative mornings. Parenteral analgesic admini stration (P < 0.001) and visual analogue pain scores (P < 0.05) were l ower in the patients receiving epidural anaesthesia and time to first parenteral analgesia was longer (P < 0. 005). Oxygen consumption, carb on dioxide production, and energy expenditure increased after surgery (all P < 0.001) but were very similar in the two groups (all P greater -than-or-equal-to 0.8) before and after surgery. Despite substantial e ffects on postoperative pain, we conclude that oxygen consumption and energy expenditure following major abdominal surgery are not diminishe d by perioperative epidural anaesthesia and analgesia.