The utility of heart rate variability as a prognostic factor in children with traumatic brain injury

OBJECTIVE: This study aimed to do a literature review to prove the hypothesis that a change in autonomous nervous system regulation, more precisely a decrease in heart rate variability (HRV), is associated with a worse outcome and could be used as a prognostic factor in children with TBI. METHODS: Databases (Pubmed, World of Science and Scopus) studies were conducted from 1996 to 2017, considering HRV in children with TBI. Seven studies were analyzed. RESULTS: Patients that became brain dead had a markedly lower LF/HF ratio, with a significant decrease after the first few hours of hospitalization. Patients with a more favorable prognosis had significantly higher LF/HF ratios. DISCUSSION: The HRV can be useful when determining the severity of neurological damage and a prognostic factor in the evaluation of its recovery. However, to assess the true value of HRV monitoring in children with TBI, a prospective study with identified thresholds for HRV, comparison to the standard methods of assessment and predictions should be made blinded to outcome at admission and then through the clinical course including the post-acute phase of rehabilitation. In the absence of this, any recommendation for its use as a prognostic tool may be premature.