Reference values for cerebral blood flow velocities in critically ill, sedated children.

Objective: Transcranial Doppler ultrasound (TCD) is increasingly being used in the pediatric intensive care unit to assess cerebral hemodynamics during critical illness. However, no normative data in this patient population have been published to date. Therefore, we aimed to describe the anterior and posterior cerebral blood flow velocities in critically ill children undergoing mechanical ventilation and sedation.

Design: A prospective, observational cohort study was performed. Children with known or suspected acute or chronic neurologic conditions were excluded. Participants underwent TCD measurement of middle cerebral and basilar artery flow velocities.

Results: One hundred and forty children newborn to 17 years of age were enrolled. Measured values were lower in this cohort of children than the previously published cerebral flow velocities of normal, healthy children.

Conclusions: Cerebral blood flow velocities of the basal cerebral arteries in critically ill, mechanically ventilated, sedated children are lower than in healthy children of the same age and gender published in previous studies. As such, the cerebral blood flow velocity (CBFV) values reported here may serve as a more accurate reference point when using TCD as a clinical tool to diagnose CBFV abnormalities and guide therapy in this patient population.