Early versus Late Parenteral Nutrition in the ICU
The EPaNIC study enrolled 4,640 critically ill adults who were nutritionally at risk and randomized them to either early (ICU day 3) or late (ICU day 8) supplemental parenteral nutrition (PN). In this study involving relatively thin patients with short ICU stays who were receiving tight glycemic control, early PN did not result in lower rates of mortality vs. late PN despite delivering significantly more calories in the first ICU week. In fact, late initiation of PN was associated with shorter duration of mechanical ventilation, lower incidence of renal replacement therapy, lower incidence of infections, and shorter ICU and hospital length of stay. Features of this study limiting external validity: most subjects had BMI 20–30, over 60% of subjects were post-cardiac surgery, overall median ICU stay was only 3 days, overall mortality was only 6%, nutritional management after ICU discharge was not controlled.