Cerebral Hemodynamics During Neonatal Cerebrospinal Fluid Removal

Standard treatment of neonatal posthemorrhagic hydrocephalus is cerebrospinal fluid removal. The aim of this study was to assess how much cerebrospinal fluid volume removal, by ventricular reservoir taps, is needed to improve cerebral hemodynamics and oxygenation in neonatal posthemorrhagic hydrocephalus.

Cerebral hemodynamics and oxygenation were continuously monitored by near-infrared spectroscopy in four newborns (one term and three preterm) during 28 ventricular reservoir taps. At each tap, 10 mL/kg of cerebrospinal fluid was removed. Near-infrared spectroscopy detected changes in the concentration of oxy-hemoglobin and total hemoglobin, considered as estimates of cerebral blood flow and volume, respectively. Cerebral tissue oxygenation index was also measured. During cerebrospinal fluid removal, variation in cerebral blood flow, volume, and oxygenation were analyzed by repeated measures analysis of variance. The associations between changes in cerebral hemodynamics and oxygenation, during cerebrospinal fluid removal and after its conclusion, were analyzed by Pearson's r correlation coefficient.

A significant increase in cerebral blood flow and volume was already evident at 50% of targeted cerebrospinal fluid volume removal (P < 0.001). Although cerebral tissue oxygenation index absolute value remained unchanged, variations in cerebral blood flow and oxygenation were positively correlated, both during cerebrospinal fluid removal and after its conclusion (r = 0.57; P = 0.002).

On the basis of the results from this small cohort, the volume of cerebrospinal fluid removal associated with an improvement in cerebral hemodynamics and perfusion seems to be less than the traditional 10 mL/kg. Further research is needed to define the potential role of near-infrared spectroscopy monitoring to individualize cerebrospinal fluid removal.