Introduction
Traumatic brain injury (TBI) remains a challenging issue in critical
care medicine due to its contribution to the majority of trauma-related
deaths (1-3). TBI refers to non-congenital
brain injury, initiated with focal or diffuse lesions at the time of the
primary injury and possibly prolonged and exacerbated by a set of
complex systemic and local events that results in secondary brain injury
(4). The secondary injury is found to be
promoted by several diverse etiologies, including metabolic changes,
inflammation, ischemia, oedema, and excitotoxicity
(5).
In the last two decades, investigators have made great progress in
understanding the main mechanistic pathways linking inflammation to
secondary brain injury after trauma (6).
Post-traumatic neuroinflammation, the neurogenic inflammation following
TBI, is primarily developed by several extracellular and intracellular
signalling pathways and is found to be a key contributor to secondary
injuries (4,
7). TBI also initiates systemic
inflammatory response syndrome (SIRS), which is found to be a potential
factor in raising the risk of nosocomial infection or multiple organ
dysfunction (MOD) (8). SIRS score
potentially predicts the length of hospital stay (LOS) and patients’
mortality (9). In the Intensive Care Unit
(ICU), critically ill patients receive some supportive care, including
nutritional support and mobilization in order to restore or maintain
organ function. In critically ill TBI patients, early nutritional
support via enteral route is of particular interest due to the enhanced
neurological recovery, shortened LOS, and reduced mortality
(10, 11).
Multiple lines of evidence have illustrated a direct correlation between
certain dietary agents and reduced levels of inflammatory markers
(12, 13).
More specifically, providing ICU patients with immune-modulating
nutrients (e.g., antioxidants, omega-3 fatty acids, glutamine, and
arginine) not only prevents malnutrition, but also results in favourable
alterations in inflammatory components, lipid profiles, antioxidant
levels, intestinal microbial balance, and their acquired immune function
(14-16). However, there is a scarcity of
clinical knowledge about assessing the effect of antioxidant-rich
enteral formulas on the clinical and biochemical outcomes of ICU
patients. The Dietary inflammatory index (DII®) is a
literature-derived tool, specifically developed to evaluate the
inflammatory potential of food components on inflammatory biomarkers,
such as C-reactive protein (CRP) (17). To
our knowledge, there is no intervention study based on the DII score in
critically ill TBI patients. Given that and due to the paucity of data
on the effect of the DII score on metabolic and inflammatory responses
in critically ill patients, this pilot study aimed to assess the effects
of a low DII score enteral formula on metabolic and inflammatory factors
of TBI patients admitted to ICU.