Authors' reply: Randomized clinical trial of the effect of postoperative intravenous fluid restriction on recovery after elective colorectal surgery (Br J Surg 2006; 93: 1469–1474)

Extract

Sir

The authors welcome the chance to reply to some of the points raised in the letter from Tornero-Campello. The present study was designed to investigate the effect of postoperative intravenous fluid restriction on patient recovery. We felt that in the light of the evidence already published it would be unethical to use the levels of intraoperative fluid used in the previous trials. For this reason we used a conservative intraoperative protocol in all patients and investigated the effect of restriction in the postoperative period. The main difference between our trial and both the Lobo and Nisanevich trials is the volume of fluid infused on the day of operation. The difference between groups in the previous trials was almost 3L on the day of operation whereas in our trial the difference was only around 1L. This difference, we believe, explains the larger change in patient weight as well as the differences in recovery of GI function, hospital stay and complications. It would appear that the excess fluid in the immediate perioperative period at the height of the surgical stress response is what contributes to the delay in recovery and that in the days following operation the body is more able to deal with any excess fluid administered.