Randomized controlled trials are needed to help guide optimal nutritional support of critically ill children during the first week of critical illness. We found little evidence to support or refute the suggested need for nutritional support in these children. While more research is needed, there are a number of challenges that researchers face in this area. These include the small number of children available for study, fewer funding opportunities for nonpharmacological nutritional interventions, and ethical concerns related to experimental protocols among this critically ill population. Further, methodological challenges exist, including the difficulty of blinding due to the nature of the intervention, heterogeneity
of the patient population (comorbidities, admission diagnosis, age), and the large sample size required to show a change because of the low mortality rate in paediatric intensive care. Nevertheless, future multicentre trials are urgently needed. These must ensure methodological rigour by examining potential risks for bias at the design stage (for example, in blinding outcome assessors or using objective outcomes, such as organ dysfunction scores, that are less prone to biased assessments or reporting). Our search update found a protocol for an international, multicenter randomized
controlled trial comparing “early versus late initiation of parenteral nutrition when enteral nutrition fails to reach preset caloric targets in critically ill children” (Fivez 2015). No results are yet available; these will be added to future updates of this review.