Epidural anaesthesia and analgesia do not affect energy expenditure after major abdominal surgery

James M. Watters MDFRCSC 0 1 Roderick J. March 0 1 Dennis Desai 0 1 Kent Monteith 0 ~ Jeffrey B. Hurtig MDFRCPC~ 0 0 From the Departments of Surgery 1 and AnaesthesiaS, University of Ottawa, Ottawa Civic Hospital , 1053Carting Avenue, Ottawa, Ontario , Canada KIY 4E9. This work is supported by Medical Research Council of Canada Grant MT-10060. Dr. Watters is a Career Scientist of the Ontario Ministry of Health. Acceptedfor publication 5th December , 1992 Our objective was to determine the effect o f perioperative epidural anaesthesia and analgesia on the increase in energy expenditure which accompanies major elective abdominal surgery in a prospective, randomized study. Eight patients undergoing elective resections o f the colon and/or rectum received general anaesthesia alone (nitrous oxide, oxygen, and isoflurane, supplemented with intravenous fentanyl to a maximum o f 10 #g' kg-~), and 12patients receivedperioperative epidural anaesthesia and analgesia using lidocaine (carbonated lidocaine 2% with epinephrine 1:200,000, 20 ml over 30 rain) and morphine (preservative-free morphine 0.10 mg" kg -I after catheter insertion and 0.05 to 0.10 mg" kg -~ every 12 hr as needed until the morning following surgery) via a lower lumbar catheter in addition to general anaesthesia. Respiratory gas exchange was measured using a metabolic cart and canopy system early on the morning o f surgery, six hours postoperatively, and on the first and second postoperative mornings. Parenteral analgesic administration (P < 0.001) and visual analogue pain scores (P < 0.05) were lower in the patients receiving epidural anaesthesia and time to first parenteral analgesia was longer (P < 0.005). Oxygen consumption, carbon dioxide production, and energy expenditure increased after surgery (all P < 0.001) but were very similar in the two groups (all P >- 0.8) before and after surgery. Despite substantial effects on postoperative pain, we conclude that oxygen consumption and energy expenditurefollowing major abdominal surgery are not diminished by perioperative epidural anaesthesia and analgesia. - Notre intention est de d~terminer l'effet de l'anesth~sie et analg~sie $pidurales p~riop~ratoires sur l'accroissement de la d~pense energ~tique qui accompagne une chirurgie abdominale majeure par une dtude prospective et randomis~e. Huit patients programm~s pour des r~sections de colon et/ou de rectum re~oivent une anesth~sie g~ndrale simple (protoxyde d'azote, oxyg~ne et isoflurane, fentanyl intraveineux jusqu'iJ un maxim u m de I0 #g" kg -I) et 12 patients re~oivent une anesth~sie et une analgdsie ~pidurale p~riop~ratoires avec de la lidoca~ne (lidocai'ne carbonat~e 2% adr~nalin~e 1.'200000, 20 ml en trente minutes et de la morphine sans pr~servatif O,lO rag" kg -t) d~s Hnsertion du catheter et 0,05 ~ 0,1 rag" kg -! routes les 12 heures au besoin jusqu'au lendemain de la chirurgie, par un catheter lombaire bas en plus d'une anesth~sie g~n~rale. Les ~changes respiratoires sont mesur~s sur un chariot utilitaire m~tabolique trt le matin avant la chirurgie, six heures apr~s la chirurgie puis le I e et le 2 e matins postop~ratoires. L'administration d'analg~sique par voie parent$rale (tous P < 0,001) et les r~sultats de l~chelle visuelle analogue de la douleur sont inf~rieurs chez les patients b~n~ficiant d'une anesth~sie ~pidurale et le d~lai de la premibre analg~sieparent~rale est plus long (P < 0,005). La consommation d'oxyg~ne, la production de CO2 et les ddpenses ~nerg~tiques augmentent aprds la chirurgie (tous P < 0,001), et de la m~me manikre dans les dix groupes (P > 0,8) avant et aprbs la chirurgie. Malgr~ un effet substantiel sur la douleur postop~ratoire, nots concluons que la consommation d'O2 et que la d~pense d~nergie apr~s une chirurgie abdominale majeure ne sont pas diminu~es p a r une anesth~sie et une analg~sie pkridurales. The importance of afferent neural signals from the site of tissue injury to the central nervous system for the rapid initiation of endocrine responses was established by the animal studies of Hume, Egdahl and colleagues during Watters el aL: ENERGY EXPENDITURE the 1950s.~-3 More recently, neural blockade by epidural anaesthesia has been shown to minimize cortisol and other hormonal responses to lower abdominal and pelvic surgical procedures. 4 While our understanding of the regulatory pathways which mediate host responses to acute surgical illness has evolved in recent years to include cytokines and other factors, recognition of the importance of afferent neural signals during and after elective surgery has continued. 5,6 The inhibition of such signals should minimize postoperative pain following major operation and could serve to limit increases in metabolic and cardiopulmonary demand. We hypothesized that the inhibition of afferent neural signals from the site of surgery by perioperative epidural anaesthesia and analgesia (using lidocaine and morphine) would minimize the metabolic responses to major elective abdominal surgical procedures. The purpose of this study was to determine the effect of epidural anaesthesia and analgesia on the increase in energy expenditure which accompanies resections of the colon and/or rectum. Methods Consecutive adult patients of either sex who were scheduled to undergo elective colorectal resection were eligible for study excluding those with a contraindication of epidural anaesthesia, diabetes mellitus, or receiving betaadrenergic blocking agents or corticosteroids. Patients known before laparotomy to have metastatic cancer were also excluded. The protocol was reviewed and approved by the Research Ethics Committee of the Ottawa Civic Hospital and informed, written consent was obtained from each patient. Patients were randomized to receive perioperative epidural anaesthesia (EA + GA) or not (GA alone) using sealed envelopes prepared from a table of random numbers. General anaesthesia in both groups was with nitrous oxide, oxygen, a n d isoflurane; supplementation was by intravenous fentanyl to a maximum of 10 ~tg-kg -l. Patients received supplemental neuromuscular blockade as required. Patients randomized to the epidural anaesthesia group had an epidural catheter inserted at the lower lumbar level by the attending anaesthetist prior to induction of general anaesthesia. Carbonated lidocaine 2% with epinephrine (1:200,000), 20 ml over 30 min, and preservative-free morphine 0.10 m g - k g -I were injected into the epidural space following insertion of a catheter and administration of a test dose of the lidocaine preparation. Mid-thoracic sensory level of anaesthesia was confirmed by pinprick. Additional lidocaine, 10 ml, was given every 90 min during the surgical procedure and once following surgery, 90 min after the previous dose. Patients randomized to the control group were managed in an entirely comparable manner with the exception that they did not have an epidural catheter inserted. All patients were transferred to the recovery roo (...truncated)