Related Experiment Videos
Clinical death and the measurement of stressed vascular volume
1Division of Critical Care, Royal Victoria Hospital, McGill University, Montréal, PQ, Canada.
Objectives:
To measure stressed vascular volume in humans and to review the concepts of stressed and unstressed vascular volume.
Design:
Observational study during surgical procedure.
Setting:
Operating room at a university hospital.
Patients:
Five patients undergoing hypothermic circulatory arrest for surgery on major vessels.
Intervention:
We measured the volume that drained from the patient to the reservoir of the pump when the pump was turned off.
Measurements And Main Results:
Stressed volume was 20.2+/-1.0 mL/kg, which is 30% of the predicted blood volume of these patients.
Conclusion:
The amount of blood volume that determines vascular filling pressure is only about a quarter of the total predicted volume, which means that there is a large reserve of unstressed volume that can be recruited to maintain vascular filling pressure.