Cerebral oxygenation in neonatal and pediatric patients during veno-arterial extracorporeal life support

Objective: To observe the effects of right carotid artery ligation and variations in extracorporeal life support (ECLS) flow on regional cerebral oxygenation index (rSO(2)i) measured using near infrared spectroscopy. Design: Prospective observational study. Setting: Tertiary children's hospital. Patients: Eleven neonatal and pediatric patients requiring veno-arterial ECLS support between June 2000 and March 2003. Interventions: Near infrared spectroscopy probe placement on left and right frontal regions of patients undergoing ECLS, before vessel cannulation or within 24 hrs of initiation of ECLS. Measurements and Main Results: Regional cerebral oxygenation was measured every minute for 72 hrs or until the patient was decannulated. The effect of cannulation on rS0(2)i from each hemisphere of the brain and the relationship between ECLS flow and rS0(2)i during ECLS support and trialing off periods were determined. Ligation of the right carotid artery resulted in a 12-25% decrease in rS0(2)i from baseline in the right frontal region for a duration ranging from 17 to 45 mins before returning toward baseline. No substantial change in the left frontal region rS0(2)i was detected during cannulation. Following this depression in rS0(2)i on the right, there was a transient increase above baseline in rS0(2)i observed in both hemispheres on initiating ECLS. No correlation between ECLS flow and rS02i was found over the 72-hr period. Periods of trialing off ECLS were not related to any change in rS0(2)i in either hemisphere. Conclusions: This study demonstrated no relationship between ECLS flow and rS0(2)i changes during the 72-hr observation period. A brief period of cerebral oxygen desaturation of the right frontal region at the time of right carotid ligation was seen in all three study patients examined during cannulation, followed by an increased rS0(2)i with initiation of ECLS flow. Near infrared spectroscopy measurement may offer an important adjunct for neurologic monitoring of ECLS patients.