Effect of dexmedetomidine on cerebral blood flow velocity, cerebral metabolic rate, and carbon dioxide response in normal humans.

Background: Dexmedetomidine reduces cerebral blood flow (CBF) in humans and animals. In animal investigations, cerebral metabolic rate (CMR) was unchanged. Therefore, the authors hypothesized that dexmedetomidine would cause a decrease in the CBF/CMR ratio with even further reduction by superimposed hyperventilation.

Pressure on the face while in the prone position: ProneView versus Prone Positioner.

Study Objective: To measure the surface pressure on the face of a patient placed in the prone position with the most commonly used prone positioning devices, a non-face-contoured positioner (PP) and a new face-contoured device (PV).

Design: Prospective, randomized comparison.

Setting: Operating room in an American academic medical center.