Relationship of cerebral blood volume with arterial and venous flow velocities in extremely low-birth- weight infants

Abstract Purpose: Unstable cerebral blood flow is theorised to contribute to the occurrence of intraventricular haemorrhage (IVH) in extremely low-birth-weight infants (ELBWIs), which can be caused by increased arterial flow, increased venous pressure, and impaired autoregulation of brain vasculature. This study aimed to investigate such instability by checking for correlations of cerebral blood volume (CBV), as measured by near-infrared spectroscopy (NIRS), with the flow velocities of the anterior cerebral artery (ACA) and internal cerebral vein (ICV), as measured by Doppler ultrasonography. Methods: Data were retrospectively analysed from 30 ELBWIs with a high likelihood of healthy development, uncomplicated by symptomatic patent ductus arteriosus, which can influence ACA velocity, or severe IVH (grade ≥3), which can influence ICV velocity and CBV. Results: CBV was not associated with ACA velocity; however, it was significantly correlated with ICV velocity (Pearson’s R = 0.59 [95% CI: 0.29–0.78], P = 0.00061). Conclusions: ICV flow velocity is difficult to continuously monitor using ultrasonography; however, CBV can be continuously monitored by computation from NIRS measurements. Our findings suggest that this technology could be useful in future research into how IVH can be prevented by neonatal monitoring.