Cerebral oxygen saturation monitoring in pediatric altered mental status patients

A pilot study assessing the potential utility of cerebral oximetry (local cerebral oxygen saturation [rcSO2]) in children presenting to the emergency department (ED) with altered mental status (AMS) and no history of trauma.

Patients who presented to a tertiary pediatric ED with AMS were monitored with left and right cerebral near-infrared spectroscopy probes and the first 30 minutes of rcSO2 data was analyzed. Patients with a history of trauma were excluded. Patients with an abnormal head computed tomography (CT) (n = 146) were compared with those with a negative head CT (n = 45).

Mean rcSO2 values were consistent during each time period studied (5, 10, 20, and 30 minutes). In this study population, rcSO2 less than 50% or greater than 80% and increased absolute difference between the left and right rcSO2 measurements were associated with an abnormal CT scan. A difference of 12.2% between the left and right rcSO2 values had a 100% positive predictive value for an abnormal head CT among our patients. Cumulative graphical plots of rcSO2 trends showed that values <50% were associated with subdural hematomas (SDH) and values >80% were associated with epidural hematomas (EDH).

This study demonstrated that cerebral oximetry can noninvasively detect altered cerebral physiology among a selected patient population. The difference between the left and right rcSO2 readings most reliably identified those subjects with altered cerebral physiology. In the future, rcSO2 monitoring has the potential to be used as a screening tool to identify, localize, and characterize intracranial injuries among children with AMS without a history of trauma.