Hypoenergetic feeding does not improve outcomes in critically ill patients with premorbid obesity: a post hoc analysis of a randomized controlled trial

Abstract

Optimal energy goals for adult, obese critically ill surgical patients are unclear. To date, there has been little data comparing feeding regimens for obese and non-obese critically ill surgical patients and the effect on outcomes. The objective was to compare the effect of hypoenergetic and euenergetic feeding goals in critically ill obese patients on outcomes, including infection, intensive care unit length of stay, and mortality. We hypothesized that hypoenergetic feeding of patients with premorbid obesity (body mass index ≥ 30 kg•m−2) during critical illness does not affect clinical outcomes. Post hoc analyses were performed on critically ill surgical patients enrolled in a randomized controlled trial. Patients were randomized to receive 25-30 kcal•kg−1•d−1 (105-126 kJ.kg−1•d−1, euenergetic) or 12.5-15 kcal•kg−1•d−1 (52-63 kJ.kg−1 •d−1, hypoenergetic), with equal protein allocation (1.5 g•kg−1•d−1). The effect of feeding regimen on outcomes in obese and nonobese patients were assessed. Of the 83 patients, 30 (36.1%) were obese (body mass index ≥ 30 kg•m−2). Average energy intake differed based on feeding regimen (hypoenergetic: 982±61 vs euenergetic: 1338±92 kcal•d−1, P = .02). Comparing obese and nonobese patients, there was no difference in the percentage acquiring an infection (66.7% [20/30] vs 77.4% [41/53], P = .29), intensive care unit length of stay (16.4±3.7 vs 14.3±0.9 days, P = .39), or mortality (10% [3/30] vs 7.6% [4/53], P = .7). Within the subset of obese patients, the percentage acquiring an infection (hypoenergetic: 78.9% [15/19] vs euenergetic: 45.5% [5/11], P = .11) was not affected by the feeding regimen. Within the subset of nonobese patients, there was a trend toward more infections in the euenergetic group (hypoenergetic: 63.6% [14/22] vs euenergetic: 87.1% [27/31], P = .05). Hypoenergetic feeding does not appear to affect clinical outcomes positively or negatively in critically ill patients with premorbid obesity.