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Updated: Sep 22, 2026
Optimized System for Cerebral Perfusion Monitoring in the Rat Stroke Model of Intraluminal Middle Cerebral Artery Occlusion
Published on: February 17, 2013
[Cerebral blood flow rate during cardiopulmonary bypass and optimal cerebral perfusion flow rate during separated
Insights
Cerebral blood flow (CBF) during cardiopulmonary bypass is linked to systemic flow rate, not blood pressure. An innominate artery flow rate of 5.5 ml/kg/min ensures adequate brain perfusion under moderate hypothermia.
Area of Science:
- Cardiovascular Physiology
- Neurology
- Surgical Perfusion
Context:
- Establishing reliable cerebral blood flow (CBF) metrics during cardiopulmonary bypass (CPB) and separated brain perfusion remains a challenge.
- Current theories lack definitive guidance for optimizing brain perfusion during these procedures.
Purpose:
- To investigate the relationship between CBF and systemic flow rate or blood pressure during CPB.
- To determine the optimal innominate artery flow rate for separated brain perfusion.
Summary:
- CBF during CPB demonstrated a positive correlation with systemic flow rate (r=0.62, p<0.01) but showed minimal association with blood pressure.
- Innominate artery flow rate influenced CBF significantly below 9 ml/kg/min, with minimal change above this threshold.
- Cerebral oxygen consumption remained stable under moderate hypothermia (26-28°C) when CBF was maintained at 25 ml/100 g brain/min.
Impact:
- Identifies systemic flow rate as a key determinant of CBF during CPB.
- Provides a target innominate artery flow rate (5.5 ml/kg/min) to maintain adequate cerebral perfusion during separated brain perfusion.
- Offers critical data for refining perfusion strategies in cardiac surgery to protect brain function.
Abstract:
There is no established theory to determine the cerebral blood flow rate (CBF) during not only the standard cardiopulmonary bypass but during the cardiopulmonary bypass with separated brain perfusion. This study was carried out to answer the following questions. (1) what is the relationship during the cardiopulmonary bypass between CBF and systemic flow rate or blood pressure?. (2) what is the optimal flow rate to the innominate artery during the separated brain perfusion? Twenty-one patients were selected for this study, who were operated under the cardiopulmonary bypass with a standard roller pump and a membrane oxygenator under moderate hypothermia (nasopharyngeal temperature of 26-28 degrees C). Systemic flow rate was maintained between 40 and 70 ml/kg/min. CBF before the cardiopulmonary bypass was 30.6 +/- 5.5 ml/100 g brain/min, and increased to 33.8 +/- 8.9 ml/100 g brain/min during the cardiopulmonary bypass. CBF was proportional to systemic flow rate (r = 0.62, p less than 0.01) and showed poor association with blood pressure ranged from 35 to 94 mmHg. As for the relationship between innominate arterial and cerebral blood flow rate, CBF linearly followed the decrease of innominate arterial flow rate to below about 9 ml/kg/min, but showed almost no changes when innominate arterial flow rate was over 9 ml/kg/min. It was observed that cerebral oxygen consumption did not decrease significantly under moderate hypothermia (26-28 degrees C), as far as CBF of 25 ml/100 g brain/min was maintained. Based on the relationship between innominate arterial and cerebral blood flow rate, it was shown that the innominate arterial flow rate to provide CBF of 25 ml/100 g brain/min was 5.5 ml/kg/min.(ABSTRACT TRUNCATED AT 250 WORDS)
