Dynamic trend monitoring of cerebral blood flow velocity in newborn infants.

A method for obtaining reproducible Doppler cerebral blood flow velocity (CBFV) measurements over several hours, utilizing a probe fixation technique and an on-line system for making beat-to-beat area under the curve (AUC) measurements, is described. Thirty heartbeat samples were collected at three time intervals over 3 hours in a group of 22 healthy preterm infants. The stability of the AUC measurements despite changes in behavioral state was demonstrated by randomized block ANOVA. The sampling error was +/- 6.92%, with 95% confidence intervals of +/- 13.1%. By facilitating reproducible serial measurements of CBFV, this trend monitoring technique encourages a dynamic view of cerebrovascular control, and may be used to probe central nervous system autoregulatory pathophysiology and to evaluate the effects of therapeutic interventions.