Evidence on nutritional therapy practice guidelines and implementation in adult critically ill patients: A systematic scoping review.

This is a scoping review, not a meta-analysis, so it maps what has been studied rather than combining effect sizes or proving a guideline works. The included studies were mainly non-randomised before-after or retrospective designs in tertiary ICUs, so nutrition delivery may have changed because of patient mix, staffing, other ICU care or secular trends. Guidelines, protocols, algorithms and outcome measures differed across studies, and the review did not pool them. Mortality and clinical outcomes were not consistently improved; some included studies reported deaths before and after protocol use, so the review cannot show a survival benefit. The review focused on enteral and parenteral nutrition guidelines, not oral diet or swallowing therapy, and most evidence concerned ICU patients, so it may not apply to less acute settings. No studies were excluded for low quality, and grey literature quality was judged by reviewer-developed scoring.

Do not conclude that ICU nutrition guidelines have been proven to reduce mortality. The review maps mostly non-randomised before-after studies, and nutrition delivery changed alongside other ICU treatments, so the guideline alone cannot be isolated.