Impact of cerebral edema on diffuse optical spectroscopy quantification during extracorporeal membrane oxygenation (ECMO)

Extracorporeal membrane oxygenation (ECMO) is an important therapy for critically ill children but survivors have neurodevelopmental impairments. Cerebral inflammatory response resulting in brain edema is observed on ECMO. This pathologic response may adversely impact the quantitative accuracy of diffuse optical spectroscopy (DOS) neuromonitoring (including commercial NIRS) which commonly assumes a 75% water fraction. Using fresh brain tissue desiccation, we directly quantified the severity of cerebral edema in pediatric swine following cardiac arrest, CPR and 22-24 hours of ECMO therapy. The fractional error in DOS quantification of cerebral hemodynamics from assuming 75% water fraction was determined to be <5%.