Randomized trial Randomized clinical trial of the effects of immediate enteral nutrition on metabolic responses to major colorectal surgery in an enhanced recovery protocol M. Soop 1,2 , G. L. Carlson 3 , J. Hopkinson 3 , S. Clarke 3 , A. Thorell 1,2 , J. Nygren 1,2 and O. Ljungqvist 1,2 1 Centre for Surgical Sciences, Karolinska Institute, Karolinska University Hospital, Huddinge, Sweden, 2 Centre for Gastrointestinal Disease, Ersta Hospital, Stockholm, Sweden and the 3 Injury Research Group, University of Manchester, Hope Hospital, Salford, UK Correspondence to: Dr O. Ljungqvist, Centre for Gastrointestinal Disease, Ersta Hospital, Box 4622, SE 116 91, Stockholm, Sweden (e-mail: olle.ljungqvist@ersta.se) Background: The effects of immediate postoperative enteral nutrition on postoperative nitrogen balance and insulin resistance were studied in patients subjected to an enhanced-recovery protocol. Methods: Eighteen patients undergoing major colorectal surgery in an enhanced-recovery protocol were randomized to immediate postoperative enteral feeding for 4 days with either complete or hypocaloric nutrition. Nitrogen balance and changes in glucose kinetics, substrate utilization (indirect calorimetry) and insulin sensitivity (hyperinsulinaemic–euglycaemic clamp) were measured. Values are mean(s.e.m.). Results: Mean postoperative urinary nitrogen losses were low (10·7(1·0) versus 10·5(0·7) g per day for complete versus hypocaloric nutrition) and insulin resistance was insignificant (− 20(7) versus − 27(11) per cent), with no difference between groups. Complete enteral feeding was given without hyperglycaemia (blood glucose concentration 5·8(0·4) versus 5·0(0·4) mmol/l) and resulted in nitrogen balance (+ 0·1(0·8) versus − 12·6(0·6) g nitrogen per day; P < 0·001). Conclusion: This enhanced-recovery protocol was associated with minimal postoperative insulin resistance and nitrogen losses after surgery. Immediate postoperative enteral nutrition was provided without hyperglycaemia and resulted in nitrogen balance. Presented in part to the 25th Congress of the European Society for Clinical Metabolism and Nutrition, Cannes, France, September 2003 Paper accepted 8 May 2004 Published online 7 August 2004 in Wiley InterScience (www.bjs.co.uk). DOI: 10.1002/bjs.4642 Introduction Surgical treatment is associated with characteristic metabolic responses in the postoperative period. Whole- body nitrogen balance is affected by accelerated nitrogen losses in the first several days after operation 1 . Postopera- tive glucose metabolism is characterized by a pronounced resistance to the effects of insulin, resulting in increased endogenous glucose release, impaired peripheral glucose disposal and hyperglycaemia 2 . Although it has been diffi- cult to link protein losses or balance to clinical outcome 3 , postoperative insulin resistance has been shown to be an independent predictor of duration of postoperative hospital The Editors have satisfied themselves that all authors have contributed significantly to this publication stay 2 . The clinical significance of stress-induced insulin resistance is further illustrated by a recent trial in which intensive treatment of hyperglycaemia with insulin infu- sion significantly reduced mortality and morbidity rates in surgical patients in intensive care 4 . Major surgery is traditionally followed by hypocaloric nutrition in the form of intravenous glucose 25 – 50 mg/ml until full oral diet is resumed after 5–7 days 5,6 . Such nutrition provides little or no nitrogen. Furthermore, hypocaloric nutrition in itself induces pronounced insulin resistance in healthy volunteers 7 . Late resumption of a full diet may therefore exacerbate the metabolic response to surgery. Significant advances in perioperative care have recently been made. So-called enhanced-recovery protocols have been implemented in several surgical centres 8 . Such Copyright  2004 British Journal of Surgery Society Ltd British Journal of Surgery 2004; 91: 1138–1145 Published by John Wiley & Sons Ltd Downloaded from https://academic.oup.com/bjs/article/91/9/1138/6143711 by guest on 25 May 2022