Technology to inform the delivery of enteral nutrition in the intensive care unit

Toward nutrition improving outcome of critically ill patients: How to interpret recent feeding RCTs?

Although numerous observational studies associated underfeeding with poor outcome, recent randomized controlled trials (RCTs) have shown that early full nutritional support does not benefit critically ill patients and may induce dose-dependent harm. Some researchers have suggested that the absence of benefit in RCTs may be attributed to overrepresentation of patients deemed at low nutritional risk, or to a too low amino acid versus non-protein energy dose in the nutritional formula. However, these hypotheses have not been confirmed by strong evidence. RCTs have not revealed any subgroup benefiting from early full nutritional support, nor benefit from increased amino acid doses or from indirect calorimetry-based energy dosing targeted at 100% of energy expenditure. Mechanistic studies attributed the absence of benefit of early feeding to anabolic resistance and futile catabolism of extra provided amino acids, and to feeding-induced suppression of recovery-enhancing pathways such as autophagy and ketogenesis, which opened perspectives for fasting-mimicking diets and ketone supplementation. Yet, the presence or absence of an anabolic response to feeding cannot be predicted or monitored and likely differs over time and among patients. In the absence of such monitor, the value of indirect calorimetry seems obscure, especially in the acute phase of illness. Until now, large feeding RCTs have focused on interventions that were initiated in the first week of critical illness. There are no large RCTs that investigated the impact of different feeding strategies initiated after the acute phase and continued after discharge from the intensive care unit in patients recovering from critical illness.

Small bowel feeding: do you pay the price for bypassing the stomach?

PURPOSE OF REVIEW

Hydration and nutritional support is a vital part of medical care, thus a clear understanding of the optimal approach is vital for medical professionals. This is a particularly pertinent issue for patients admitted to a critical care setting. This article aims to define the advantages and disadvantages of gastric and postpyloric feeding in the critical care setting, thus aiding decision-making for clinicians.

RECENT FINDINGS

Within the article, the main themes covered are those relating to enteral feeding tube placement, the impact of enteral feeding route on ventilator-associated pneumonia, optimization of enteral tube feeding in critical care and the impact that a chosen route may have upon gastrointestinal function.

SUMMARY

The value of enteral feeding in critical illness is proven beyond doubt and the simplest approach has long been 'if the gut works, use it'. If gastric feeding is not able to be established or is not tolerated then jejunal feeding should be considered as a preferable alternative to parenteral nutrition. Improving access to service or techniques for postpyloric tube placement would assist in optimizing nutritional support in the critical care setting.