Short term benefits of post-operative oral dietary supplements in surgical patients

The present study was undertaken to investigate the short term clinical efficacy of oral dietary supplements administered post-operatively to patients undergoing predetermined moderate to severe gastrointestinal surgery. Trial end points for comparison included effects of oral dietary supplements on nutritional intake, nutritional status and incidence of serious complications. 54 patients who were scheduled to undergo predetermined moderate to major gastrointestinal surgical procedures entered the study. They were randomly assigned to receive a normal ward diet post-operatively or the same diet supplemented ad libitum by an oral nutritional sip feed. The study period was defined as commencing from the day patients were adjudged to be capable of ingesting 'free fluids' to the day of hospital discharge. 40 patients (20 in each group) completed the study. The mean daily energy intake (KCal/day) assessed from 7 day food diaries was significantly higher in the treatment group (1833 +/- SEM 99) than in the control group (1108 +/- 56, p < 0.0001). This increase occurred not only as a consequence of energy intake from the oral dietary supplements (470 +/- 30) but also because more energy was consumed from the ward diet by the treatment than the control patients (1353 +/- 92 vs 1108 +/- 56, p < 0.02). The mean daily protein intake g/day in the treatment group (66.0 +/- 3.4) was also greater than in the control group (52.9 +/- 29 p < 0.0001). This difference was due solely to the intake in protein from the oral dietary supplements (15.7 +/- 1.0), protein intake from the ward diet being similar in the treatment (50.1 +/- 3.2) and control (52.9 +/- 29) groups. Patients in the treatment group maintained their pre-operative weight where as control patients had lostsignificant amount of their pre-operative weight by study day 3 (4.5 +/- 12 kg and by discharge (4.7 +/- 1.2 kg, p < 0.02). Pre-operative muscle function as evidenced by grip strength dynamometry decreased to a greater extent in the control than treatment group patients by study day 3 (14.6 +/- 2.2 KPa vs 2.8 +/- 2.4 < 0.03) and by discharge (10.4 +/- 3.1 KPa vs 0.10 +/- 1.9 p < 0.03). The incidence of serious infections (pneumonia, wound infection) was significantly higher in the control group (10) than in the treatment group (3, p < 0.02). It is concluded that the prescription of oral dietary supplements on an ad libitum basis to post-operative patients undergoing moderate to major gastrointestinal surgery results in clinically significant short term benefits.