A randomized placebo controlled trial of preoperative carbohydrate drinks and early postoperative nutritional supplement drinks in colorectal surgery.

Aim: There is evidence that preoperative carbohydrate drinks and postoperative nutritional supplements improve the outcome of colorectal surgery. There is little information on their individual contribution.

Method: A prospective four-arm double-blind controlled trial was carried out in which patients were randomized to carbohydrate or placebo drinks preoperatively and a polymeric supplement or placebo drink postoperatively. The primary outcome was insulin resistance (using the short insulin tolerance test and HOMA-IR). Secondary outcomes included handgrip strength, pulmonary function, intestinal permeability and postoperative complications.

Results: A total of 120 patients were randomized to four demographically well matched groups. Patients who received preoperative and postoperative supplements had better glucose homeostasis (P = 0.004), peak expiratory flow rate (P = 0.035), handgrip strength (P = 0.002) and less insulin resistance (P = 0.001) compared with those who only received placebo drinks.

Conclusion: Oral nutritional supplements given preoperatively and postoperatively improve postoperative handgrip strength, pulmonary function and insulin resistance. A weaker effect was seen in patients who received supplements either preoperatively or postoperatively. Oral nutritional supplements should be given both preoperatively and postoperatively.