Precision and normal values of cerebral blood volume in preterm neonates using time-resolved near-infrared spectroscopy

Aim: To investigate cerebral blood volume (CBV) in preterm neonates using time -resolved near-infrared spectroscopy.Methods: In this prospective observational study, time-resolved near-infrared spectroscopy measurements of CBV using tNIRS-1 were performed in 70 preterm neo- nates. For measurements, a sensor was placed for a duration of 1 min, followed by four further reapplications of the sensor, overall five measurements.Results: In this study, 70 preterm neonates with a mean +/- SD gestational age of 33.4 +/- 1.7 weeks and a birthweight of 1931 +/- 398 g were included with a postnatal age of 4.7 +/- 2.0 days. Altogether, 2383 CBV values were obtained with an overall mean of 1.85 +/- 0.30 mL/100 g brain. A total of 95% of the measured CBV values varied in a range from -0.31 to 0.33 from the overall individual mean. Taking the deviation of the mean of each single application for each patient, this range reduced from -0.07 to 0.07. The precision of the measurement defined as within-variation in CBV was 0.24 mL/100 g brain.Conclusion:The overall mean CBV in stable preterm neonates was 1.85 +/- 0.30 mL/100 g brain. The within-variation in CBV was 0.24 mL/100 g brain. Based on the precision obtained by our data, CBV of 1.85 +/- 0.30 mL/100 g brain may be assumed as normal value for this cohort.