Nutrition in Neurocritical Care

Acute brain injuries (ABIs) pose a significant global health challenge, characterized by a high incidence of overall mortality and the potential for long-term neurological disabilities. The trajectory of ABI involves primary injury and a cascade of systemic and local events leading to secondary injury. The brain, a vital regulator of metabolic activities, experiences profound metabolic alterations following ABI, resulting in aberrant cellular metabolism, hormonal shifts, and inflammatory responses. Such changes, such as hypermetabolism, hypercatabolism, and glucose intolerance, exert a negative impact on patient outcomes. Nutritional support plays a crucial role in managing secondary metabolic disorders arising from ABI. However, patients with ABI face a risk of substantial protein and energy deficits during hospitalization, leading to significant loss of lean body mass in the critical care phase. Initiation of nutrition support is essential to meet patients’ nutritional requirements, preventing malnutrition and mitigating the catabolic effects of ABI. Determining energy expenditure and managing the route, timing, and intolerance to enteral nutrition present challenges in this population. This chapter aims to provide an updated perspective on the nutritional and metabolic management of critically ill patients with acute brain injuries, incorporating recent evidence on brain metabolism. Emphasis is placed on the pivotal role of nutrition as a therapeutic strategy to maintain adequate substrate delivery to the injured brain.