Cerebral autoregulation and CO2 reactivity in anterior and posterior cerebral circulation during sevoflurane anesthesia.

The purpose of the study was to compare cerebral autoregulation (CA) and CO2 reactivity (CO2R) between the anterior and posterior circulation under sevoflurane anesthesia. We studied 9 adult ASA physical status I patients (22-47 yr) scheduled for elective orthopedic surgery. Blood flow velocity in the middle cerebral artery (Vmca) and in the basilar artery (Vba) were measured using transcranial Doppler ultrasonography.

Cerebral autoregulation in pediatric traumatic brain injury.

Objective: The aims of this study were to document the incidence of impaired cerebral autoregulation in children with traumatic brain injury using transcranial Doppler ultrasonography and to examine the relationship between autoregulatory capacity and outcome in children following traumatic brain injury.

Design: Prospective cohort study.

Setting: Harborview Medical Center (level I pediatric trauma center) in Washington state.

Ophthalmic artery blood flow velocity increases during hypocapnia.

Purpose: The effects of anesthetic management on blood flow to the optic nerve have not been well-studied. The ophthalmic artery provides the majority of the blood supply to the optic nerve via several smaller branches. Retinal blood flow has been shown to react to carbon dioxide (CO(2)) similar to intracranial vessels, but insufficient data exist for the ophthalmic artery.

Propofol: relation between brain concentrations, electroencephalogram, middle cerebral artery blood flow velocity, and cerebral oxygen extraction during induction of anesthesia.

Background: The potential benefit of propofol dose regimens that use physiologic pharmacokinetic modeling to target the brain has been demonstrated in animals, but no data are available on the rate of propofol distribution to the brain in humans. This study measured the brain uptake of propofol in humans and the simultaneous effects on electroencephalography, cerebral blood flow velocity (V(mca)), and cerebral oxygen extraction.

Methods: Seven subjects had arterial and jugular bulb catheters placed before induction.

Chronic cocaine exposure alters carbon dioxide reactivity but does not affect cerebral blood flow autoregulation in anesthetized dogs.

Background: Cocaine use is common in trauma victims. Consequently, understanding how cocaine alters normal physiology is important to providing appropriate medical care for these patients. This study was designed to identify how chronic cocaine exposure alters cerebrovascular physiology.