Butler B D, Morris W P
Department of Anesthesiology, University of Texas-Houston Medical School 77030, USA.
Undersea Hyperb Med. 1995 Jun;22(2):117-28.
Transesophageal echocardiography was used to evaluate venous bubbles produced in nine anesthetized dogs following decompression from 2.84 bar after 120 min at pressure. In five dogs a pulsed Doppler cuff probe was placed around the inferior vena cava for bubble grade determination. The transesophageal echo images demonstrated several novel or less defined events. In each case where the pulmonary artery was clearly visualized, the venous bubbles were seen to oscillate back and forth several times, bringing into question the effect of coincidental counting in routine bubble grade analysis using precordial Doppler. A second finding was that in all cases, extensive bubbling occurred in the portal veins with complete extraction by the liver sinusoids, with one exception where a portal-to-hepatic venous anastomosis was observed. Compression of the bowel released copious numbers of bubbles into the portal veins, sometimes more than were released into the inferior vena cava. Finally, large masses of foam were routinely observed in the non-dependent regions of the inferior vena cava that not only delayed the appearance of bubbles in the pulmonary artery but also allowed additional opportunity for further reaction with blood products and for coalescence to occur before reaching the pulmonary microcirculation. These novel observations are discussed in relation to the decompression process.
经食管超声心动图用于评估9只麻醉犬在2.84巴压力下维持120分钟后减压产生的静脉气泡。在5只犬中，将脉冲多普勒袖带探头置于下腔静脉周围以确定气泡等级。经食管超声图像显示了几个新的或不太明确的情况。在每例能清晰观察到肺动脉的情况下，可见静脉气泡来回振荡数次，这对使用心前区多普勒进行常规气泡等级分析时的巧合计数效果提出了质疑。第二个发现是，在所有病例中，门静脉均出现大量气泡，肝脏窦状隙将其完全清除，但有一例观察到门静脉与肝静脉吻合。压迫肠道会使大量气泡进入门静脉，有时进入门静脉的气泡比进入下腔静脉的还多。最后，在下腔静脉的非下垂区域经常观察到大量泡沫，这些泡沫不仅延迟了气泡在肺动脉中的出现，还为与血液成分进一步反应以及在到达肺微循环之前聚结提供了更多机会。本文结合减压过程对这些新观察结果进行了讨论。
