Postoperative colonic motility after tropisetron and a standardized meal in patients undergoing conventional colorectal surgery

Abstract

Early postoperative enteral nutrition is advantageous for the recovery of colonic motility but may be limited by abdominal distension, nausea, and vomiting. We aimed to investigate the tolerance of a standardized meal after pretreatment with the 5-hydroxytryptamine-3-receptor antagonist tropisetron and to study the concomitant colonic motility. Colonic motility and tone were recorded on postoperative day 1 to 3 with a combined manometry/barostat recording catheter in 12 patients who underwent open colorectal surgery with an anastomosis in the distal colon or rectum. The study protocol consisted of 30 min of baseline recordings followed by 5 mg of tropisetron intravenously. Then, motility was recorded for another 30 min before patients ingested a standardized meal to trigger the gastrocolonic response. Postprandial motility was recorded for the subsequent 60 min. The colonic motility index increased after administration of tropisetron on all three postoperative days (day 1: 34+/-11 vs 122+/-48, day 2: 55+/-19 vs 101+/-25, and day 3: 42+/-16 vs 93+/-33 mmHg/min; p<0.05). No further increase of the motility index was observed postprandially. Frequency and amplitude of contractions were virtually unaffected by tropisetron and the meal. Barostat bag volume decreased postprandially in the proximal bag on the third, and in the distal bag on the first and second postoperative day (p<0.05). Patients' condition was unaffected by the standardized meal after tropisetron administration. Tropisetron may enhance colonic motility in the early postoperative period; however, the gastrocolonic response was impaired thereafter. High caloric food intake is well tolerated early after surgery after tropisetron pretreatment.