Related Experiment Videos
Diffusion of nitrous oxide into the pleural cavity
S Kaur1, J Cortiella, C A Vacanti
1Department of Anesthesiology, UMass Memorial Medical Center, Worcester, MA 01655, USA.
British Journal of Anaesthesia
|March 7, 2002
Summary
Nitrous oxide rapidly enters the pleural space via diffusion from the lungs, not blood flow. This explains why pneumothorax volume increases quickly when using this anesthetic gas.
Area of Science:
- Anesthesiology
- Pulmonary Medicine
- Physiology
Background:
- Nitrous oxide is commonly used in anesthesia.
- The mechanism of nitrous oxide transfer into the pleural space is not fully understood.
- Rapid increases in pneumothorax volume during nitrous oxide administration have been observed.
Purpose of the Study:
- To investigate the mechanism of nitrous oxide transfer into the pleural cavity.
- To determine if diffusion or vascular transport is the primary route.
- To elucidate the cause of rapid pneumothorax volume expansion.
Main Methods:
- Six sheep were studied under general anesthesia and mechanical ventilation.
- Nitrous oxide concentration in the pleural space was measured during ventilation with 50% nitrous oxide/50% oxygen.
- Experiments were conducted with and without circulation to differentiate between diffusion and vascular transport.
Main Results:
- Nitrous oxide concentration in the pleural cavity increased rapidly when inspired.
- Pleural nitrous oxide levels decreased to zero during 100% oxygen ventilation.
- The rate of nitrous oxide increase in the pleural space was similar with and without circulation.
Conclusions:
- Nitrous oxide enters the pleural space primarily through diffusion from the alveoli.
- Vascular transport plays a minimal role in pleural nitrous oxide accumulation.
- Diffusion is the likely mechanism for rapid pneumothorax volume increase during nitrous oxide administration.