Optical topography to measure variations in regional cerebral oxygenation in an infant supported on veno-arterial extra-corporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO) is a rescue therapy for patients with cardio-respiratory failure which exposes the patient to the risk for intracranial injury. We used a 12-channel optical topography system to monitor cerebral oxygenation in a venoarterial (VA) ECMO patient during alterations in the ECMO flows. Changes in oxy-(HbO), deoxy-(HHb) and total-(HbT) haemoglobin concentrations were measured simultaneously with systemic and ECMO circuit parameters. Decreasing the flows resulted in a decrease in venous (SvO) and arterial (SpO) saturations. These were reflected in the haemoglobin data by a significant increase in HHb of varying magnitude across the 12 channels and moderate changes in HbO suggestive of cerebral arterial dilation to compensate for the lack of oxygen delivery. In the patient studied here ECMO flows appear to present a significant haemodynamic challenge to cerebral circulation.