Related Experiment Videos
Higher hematocrit improves cerebral outcome after deep hypothermic circulatory arrest
T Shin'oka1, D Shum-Tim, R A Jonas
1Department of Cardiovascular Surgery, Children's Hospital, Boston, MA 02115, USA.
The Journal of Thoracic and Cardiovascular Surgery
|December 1, 1996
Summary
Higher hematocrit levels during cardiopulmonary bypass improve cerebral recovery after deep hypothermic circulatory arrest. Extreme hemodilution can impair oxygen delivery, negatively impacting brain function.
Area of Science:
- Cardiovascular Surgery
- Neuroscience
- Biochemistry
Background:
- Hemodilution is used during deep hypothermic circulatory arrest (DHCA) to mitigate brain injury.
- Previous reports suggest varying degrees of hemodilution impact rheologic effects.
Purpose of the Study:
- To investigate the effects of different hematocrit levels during DHCA on cerebral recovery.
- To determine the optimal hematocrit for minimizing brain injury during cardiopulmonary bypass.
Main Methods:
- Seventeen piglets underwent 60 minutes of DHCA at 15°C.
- Three groups received different prime solutions, resulting in hematocrit levels of <10%, 20%, and 30%.
- Cerebral function was monitored using magnetic resonance spectroscopy, near-infrared spectroscopy, and neurological/histological assessments.
Main Results:
- Extreme hemodilution (hematocrit <10%) led to significant phosphocreatine loss and acidosis during cooling.
- Higher hematocrit groups showed less cytochrome aa3 reduction during DHCA.
- The highest hematocrit group (30%) demonstrated the best initial neurological preservation and reduced neocortex injury.
Conclusions:
- Extreme hemodilution during cardiopulmonary bypass compromises oxygen delivery and cerebral recovery.
- A higher hematocrit achieved with a blood prime is associated with improved neurological outcomes following DHCA.