Rheoencephalogram Reflects Cerebral Blood Flow Autoregulation in Pigs
Abstract
The objective of the present study was to compare systemic arterial pressure (SAP), rheoencephalogram (REG), and carotid flow (CF) measured by Doppler ultrasound. Twenty-eight anesthetized Yorkshire pigs were measured to evaluate Cerebral Blood Flow (CBF) Autoregulation (AR) during several CBF manipulations: hemorrhage, positive end-expiratory pressure (PEEP), and transitory SAP decrease and increase. Data were sampled with 200 Hz and processed off-line. 1) Hemorrhage elicited a decrease in SAP and transitory increases in REG and CF amplitude; 2) PEEP resulted in a decrease in SAP and increases in REG and CF amplitude; 3) PEEP after hemorrhage caused decreases in SAP, REG and CF amplitudes. When CBF AR was present, it was detected by both REG and carotid flow. Following hemorrhage, CBF AR was lost; CF and REG passively followed SAP. The clinical importance of these findings is that REG can be measured more conveniently and continuously in humans than can Doppler ultrasound. Therefore, measurement of CBF autoregulation by REG has potential for use as a life sign monitoring modality.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2007
- Accession Number
- ADA473927
Entities
People
- Frederick Pearce
- Michael Bodo
- Rocco Armonda
- Stephen Van Albert
Organizations
- Walter Reed Army Institute of Research