Nutritional Assessment and Nutritional Treatment Strategies for Patients After Cardiac Arrest: A Narrative Review

The aim was to synthesize current evidence on nutritional management in adult patients after cardiac arrest (CA) and to develop a structured framework for clinical practice in the absence of CA-specific nutritional guidelines. Post-cardiac arrest syndrome is characterized by systemic ischemia-reperfusion injury, metabolic stress, and organ dysfunction. Although nutritional support is an integral component of critical care, randomized controlled trials specifically evaluating nutritional strategies in patients after CA are lacking. Current practice therefore relies largely on extrapolation from general intensive care unit (ICU) guidelines, with additional uncertainty during targeted temperature management (TTM, a controlled medical therapy designed to actively lower or regulate a patient's core body temperature to improve neurological outcomes after CA). A narrative review of international guideline recommendations, randomized controlled trials in critically ill populations, CA-specific observational studies, and relevant mechanistic data was conducted. Evidence was interpreted using a hierarchical approach to distinguish high-certainty guideline-supported practices from lower-certainty observational and hypothesis-generating findings. High-level evidence from ICU guidelines supports early enteral nutrition (EN), hypocaloric feeding during the acute phase, and individualized protein provision. Observational studies in CA cohorts suggest that early EN is feasible during targeted temperature management and may be associated with improved neurological outcomes, although causality remains unproven. Temperature management reduces energy expenditure and alters substrate utilization, necessitating appropriate adjustment of caloric targets. Biomarkers such as glycemic variability, triglyceride levels, triglyceride-glucose index, and protein-related indices demonstrate prognostic associations but have not been validated as guides for nutritional prescription. In the absence of CA-specific interventional trials, nutritional management after CA should be grounded in established ICU principles and adapted according to physiological context and metabolic tolerance. The framework presented herein aims to support structured clinical decision-making while underscoring the need for prospective studies to define evidence-based, population-specific nutritional strategies.