Hemispheric Cerebral Oximetry Monitoring During Pediatric Seizure Activity in a Pediatric Emergency Department
Authors: Abramo Thomas J. , McKinney Shane , Moore James , Jacobs Richard , Albert Gregory , Meredith Mark , Porter Nicholas Hobart , Storm Elizabeth , Willis Errin , Gonzalez Cruz Velasco , Hargrave Hailey , Schneider Brad , Sharp Gergory 
Published: November 2017

Background
Sustained neuronal activity during seizures causes cellular perturbations, alterations in cerebral physiology, and potentially neurological injury, a neurological emergency. With variable clinical manifestations of seizures, frequent failure of seizure recognition by providers in pediatric and developmentally challenged patients can increase seizure complications. Neuroresuscitation should include rapid cerebral physiology assessment for increased seizure recognition and optimal neurological outcomes. In neurological emergencies, cerebral oximetry has demonstrated its utility in altered cerebral physiology and a standard combat neurological assessment tool. During adult seizures, cerebral oximetry (regional cerebral oxygen saturation [rcSO2]) has been shown as a useful neurological assessment tool, but research is lacking in pediatric emergency department (PED) seizure patients.

Objective
The aim of this study was to identify trends in rcSO2 readings for patients presenting to the PED with seizure activity and in the postseizure state in order to evaluate usefulness of rcSO2 as a neurological assessment tool in pediatric seizure patients.

Methods
This was a PED observational case series comparing hemispheric rcSO2 readings in first-time clinically evident generalized and focal seizure patients to first-time postseizure patients with no PED seizures.

Results
Generalized or focal seizure (n = 185) hemispheric rcSO2 revealed significant differences compared with nonseizure and controls' rcSO2 readings (n = 115) (P < 0.0001). Generalized and focal seizure rcSO2's were either less than 60% or greater than 80% compared with nonseizure rcSO2 (P < 0.0001). Ipsilateral focal seizure rcSO2 correlated to seizure side (P < 0.0001) and was less than the contralateral rcSO2 (P < 0.0001), with interhemispheric rcSO2 discordance greater than 16 (P < 0.0001). Seizure to preseizure rcSO2 discordance was as follows: generalized 15.2, focal: left 19.8, right 20.3 (P < 0.0001).

Conclusions
Hemispheric during-seizure rcSO2 readings significantly correlated with generalized and focal seizures and reflected altered cerebral physiology. Ipsilateral focal seizure rcSO2 readings correlated to the focal side with wide interhemispheric rcSO2 discordance. All postseizure rcSO2 readings returned to preseizure readings, showing altered cerebral physiology resolution. Overall, in generalized or focal seizure, rcSO2 readings were less than 60% or greater than 80%, and in focal seizure, interhemispheric rcSO2 discordance was greater than 10. During seizures, hemispheric rcSO2 readings demonstrated its potential pediatric seizure utility. Utilizing rcSO2 readings related to seizure activity could expedite pediatric and developmentally challenged patients' seizure recognition, cerebral assessment, and interventions especially in pharmacoresistant seizures.