Type of intravenous nutrition given in control groups is not indicated

EDITOR—We appreciated Lewis et al's wise conclusions in their study: “there seems to be no clear advantage to keeping patients nil by mouth after elective gastrointestinal resection.”1 The subtitle of the accompanying editorial sounded less prudent: “early feeding is beneficial.”2 This positive statement stimulates readers to raise several questions that cannot be answered from the study. Which diet is beneficial? By which route? And compared with which intravenous feeding?

From table 1 we note that four types of diet were used in the 11 studies (standard, elemental, oral, and immune enhancing), through four different routes (oral, nasoduodenal, nasojejunal, and jejunostomy), giving rise to seven different combinations. No indication is given of the quality and quantity of the intravenous nutrition in the control groups. This is because the original studies were more concerned with feasibility, safety, and tolerance of enteral feeding than with its effect on postoperative outcome. The control diet was consequently defined only as conventional or traditional treatment or routine intravenous crystalloid solutions or hypocaloric fluids. Moreover, in one study the control group was not nil by mouth, as a placebo was given through a nasoduodenal feeding tube.3

This issue is not an academic one. In a randomised clinical trial Lobo et al showed in postoperative patients that salt and water restriction (water ≤2 l and sodium ≤77 mmol/day) was significantly better than standard management (water roughly 3 l and sodium roughly 154 mmol/day) in reducing postoperative gastric emptying times, time to passage of flatus and stools, and postoperative stay.4

In the absence of clear information on the composition of the intravenous support in the control arm we can speculate that the advantage of early feeding, as reported in this meta-analysis, reflects not a true benefit but simply the lack of detriment due to the …