COMPARISON BETWEEN NEAR-INFRARED SPECTROSCOPY AND XE-133 CLEARANCE FOR ESTIMATION OF CEREBRAL BLOOD-FLOW IN CRITICALLY ILL PRETERM INFANTS

Estimations of cerebral blood flow were performed by both near infrared spectroscopy and xenon-133 clearance on 12 occasions in nine critically ill premature infants (26-29 gestational wk) who required mechanical ventilation and supplemental oxygen. For each study, one determination of cerebral blood flow by xenon-133 was compared with the mean of two to five measurements by near infrared done within 1-19 (median 5) h. Xenon-133 measurements ranged from 9.6-16.9 mL/100 g/min, and mean near infrared measurements ranged from 8.6-25.0 mL/100 g/min. There was a significant correlation between the two sets of measurements (r = 0.80, p < 0.001). The mean difference between the methods was 1.6 mL/100 g/min, and the 95% limits of agreement were -0.5-3.8 mL/100 g/min. This study showed that cerebral blood flow can be measured noninvasively in critically ill premature infants at the cotside by near infrared spectroscopy and by the xenon-133 clearance technique. The methods give comparable results.