Daytime only or time restricted feeding in critically ill patients: A scoping review

Objective: A scoping review was performed to understand the extent and type of published evidence in relation to restricting feeding of critically ill patients to the daytime only, with a nighttime fasting period. Introduction: Time-restricted feeding has been shown to be beneficial to long-term health. Critically ill patients admitted to intensive care units (ICUs) are traditionally fed continuously. The potential benefits or harms of daytime only feeding in the critically ill are unknown. Inclusion criteria: Studies of critically ill patients, cared for in any critical care environment, where feeding was stopped for a minimum of 6 h overnight, with any primary outcome, were included. Methods: Using the JBI framework, a search of OVID Embase, OVID Medline, CINHAL, PROSPERO, The Cochrane database and Web of Science was performed in July 2023. Results: Fourteen studies that included 868 participants, published between 1989 and 2023 met the inclusion criteria and were reported on. The patient cohorts were from general or mixed ICUs, and neurosurgical and paediatric cohorts. Feed was either administered by bolus, in cyclic patterns or continuously. The overnight fasting times ranged from 6 to 12 h, with reported primary outcomes of feed intolerance, nutritional delivery, ketosis, gastric pH, ventilator associated pneumonia and circadian rhythms. Daytime only feeding was found to increase ketosis and lower gastric acidity. Conclusions: Daytime only feeding in the critically ill has been reported, but details of its potential harms or benefits are limited by inconsistently defined outcomes and study small sample sizes.