Cerebral saturations trend with mixed venous saturations in patients undergoing extracorporeal life support

Cerebral saturation (SC_O2) monitors are noninvasive tools that continuously measure saturations in the cerebral cortex, a predominately venous bed. The purpose of this study was to see if a trend existed between measurements of SC_O2 and mixed venous saturation values (SV_O2) for patients on extracorporeal life support (ECLS). Six patients required ECLS for cardiac failure after congenital cardiac surgery, and one patient required ECLS for pulmonary failure. Patients were divided into two groups, those without systemic/pulmonary venous mixing (n=3, Group I) and those with mixing due to an intra-atrial shunt or left ventricular vent (n=4, Group II). The age of patients was 0.4±0.5 years (mean±SD), weight was 5.2±2.3 kg, and time on ECLS was 8.3±4.8 days. No significant abnormalities were seen on head imaging. A total of 786 paired data points were collected. Mean values were different; however, there was a significant trend between SC_O2 and SV_O2 for the entire sample (R²=0.66, p <0.001). Cerebral saturation trends follow mixed venous trends and, therefore, may be helpful in combination with other physical and laboratory findings in the care of the critically ill child.