Non-invasive Near-infrared Spectroscopy in Pediatric Traumatic Brain Injury

Introduction: Traumatic brain injury (TBI) is a major cause of pediatric morbidity. Near-infrared spectroscopy (NIRS) non-invasively measures regional cerebral oxygen saturation (rSO2). We hypothesized that rSO2 would decrease following sequelae of TBI, such as hemorrhage and seizure. We also hypothesized that rSO2 would be negatively and positively correlated with invasive levels of intracranial pressure (ICP) and brain tissue oxygenation (PbtO2), respectively.

Methods: We retrospectively reviewed pediatric patients who presented to a quaternary children’s hospital with Glasgow Coma Scale ≤ 12 and received NIRS monitoring. We evaluated the association between bilateral rSO2 values and ICP +/- PbtO2, as well as average rSO2 values before, during, and after seizures. We also analyzed the relationship between average daily rSO2 and location of hemorrhage.

Results: Twenty-nine pediatric patients were eligible. Among the patients who received invasive PbtO2 monitoring in addition to NIRS, bilateral rSO2 significantly, positively correlated with PbtO2 (p < 0.05). ICP was associated with unilateral rSO2. Among the patients who experienced seizures, average bilateral rSO2 during seizure activity was higher than average rSO2 two hours pre- and post- seizure activity. The variation in pre-seizure and during-seizure rSO2 was significant in the left hemisphere (p < 0.05). Average bilateral rSO2 did not vary significantly with the presence of frontal intracranial hemorrhage.

Conclusion : In children with TBI, bilateral rSO2 was positively associated with PbtO2, and unilateral rSO2 correlated with ICP. Average bilateral rSO2 was higher during seizure activity than average bilateral rSO2 pre- and post- seizure activity. rSO2 values were not significantly different in patients with or without frontal hemorrhage. Further analysis of rSO2 in relation to invasive monitoring, seizure, and hemorrhage location is needed.