硬膜静脈洞圧からみたair embolism予防法の検討

抄録

This study was designed to improve understanding of the pathogenesis of air embolism and thereby contribute to the development of effective preventive techniques. Dural venous sinus pressure (confluens sinuum pressure: CSP) was measured in pentobarbital-anesthetized mongrel dogs under conditions of spontaneous and controlled respiration, head elevation, neck compression, abdominal compression, drug- or bleeding-induced hypotension, extraneous fluid administration, and drug-induced hypertension. CSP was lower during controlled than during spontaneous respiration. When the head was raised, CSP decreased almost linearly, reaching -2.3±2.8 (mean±SD) mmHg at 45°. Upon neck compression, CSP increased significantly; even at a cuff pressure of only 5 mmHg, the negative pressure returned to zero. However, abdominal compression had little effect. Bleeding-induced hypotension caused a decrease in CSP, to 0.3±1.4 mmHg at a blood pressure of 90 mmHg. On the other hand, CSP increased markedly following fluid administration (except in the case of saline) and induced hypertension. These results suggest that continuous neck compression, fluid administration, avoidance of hypotension, and induced hypertension contribute to the prevention of air embolism.