Butler B D, Hills B A
J Appl Physiol (1985). 1985 Aug;59(2):543-7. doi: 10.1152/jappl.1985.59.2.543.
Twenty-seven paralyzed anesthetized dogs were embolized with venous air to determine the effectiveness of the pulmonary vasculature for bubble filtration or trapping. Air doses ranged from 0.05 to 0.40 ml X kg-1 X min-1 in 0.05-ml increments with ultrasonic Doppler monitors placed over arterial vessels to detect any microbubbles that crossed the lungs. Pulmonary vascular filtration of the venous air infusions was complete for the lower air doses ranging from 0.05 to 0.30 ml X kg-1 X min-1. When the air doses were increased to 0.35 ml X kg-1 X min-1, the filtration threshold was exceeded with arterial spillover of bubbles occurring in 50% of the animals and reaching 71% for 0.40 ml X kg-1 X min-1. Significant elevations were observed in pulmonary arterial pressure and pulmonary vascular resistance. Systemic blood pressure and cardiac output decreased, whereas left ventricular end-diastolic pressure remained unchanged. The results indicate that the filtration of venous bubbles by the pulmonary vasculature was complete when the air infusion rates were kept below a threshold value of 0.30 ml X kg-1 X min-1.
对27只瘫痪并麻醉的狗进行静脉空气栓塞，以确定肺血管系统对气泡过滤或捕获的有效性。空气剂量以0.05 ml的增量在0.05至0.40 ml·kg⁻¹·min⁻¹范围内变化，同时在动脉血管上方放置超声多普勒监测器，以检测任何穿过肺部的微气泡。对于0.05至0.30 ml·kg⁻¹·min⁻¹的较低空气剂量，静脉注入空气的肺血管过滤是完全的。当空气剂量增加到0.35 ml·kg⁻¹·min⁻¹时，超过了过滤阈值，50%的动物出现气泡动脉溢出，当空气剂量为0.40 ml·kg⁻¹·min⁻¹时，这一比例达到71%。肺动脉压和肺血管阻力显著升高。全身血压和心输出量下降，而左心室舒张末期压力保持不变。结果表明，当空气输注速率保持在0.30 ml·kg⁻¹·min⁻¹的阈值以下时，肺血管系统对静脉气泡的过滤是完全的。
