Chen L, Williams J J, Alexander C M, Ray R J, Marshall C, Marshall B E
McNeil Center for Research in Anesthesia, University of Pennsylvania School of Medicine, Philadelphia.
Anesth Analg. 1988 Aug;67(8):763-9.
The effect of intrapleural pressure on the hypoxic pulmonary vasoconstrictor (HPV) responses to atelectasis and hypoxia were measured in two groups of anesthetized closed chest dogs. The right lung was continuously ventilated with 100% O2. The left lung was initially ventilated with 100% O2 (hyperoxia) but subsequently underwent either reabsorption atelectasis (atelectasis; group I) or ventilation with a hypoxic gas mixture (hypoxia; group II). The mean intrapleural pressure in the left hemithorax was 5.4 cm H2O during hyperoxia, but with left lung atelectasis decreased significantly to -3.8 cm H2O by 15 minutes and to -4.2 cm H2O by 90 minutes. Venous admixture (% VA) increased significantly from 10.3% during hyperoxia to 33.2% at 15 minutes of left lung atelectasis and to 34.6% at 90 minutes. However, after sternotomy with the left lung still atelectatic, the %VA decreased significantly to 25.4% For the hypoxia group, %VA increased significantly from 9.2% during hyperoxia to 29.9% at 15 minutes of left lung hypoxia and 25.1% at 90 minutes. HPV diverted blood flow away from both atelectatic lung and hypoxic lung. However, due to the negative intrapleural pressure generated during left lung resorption atelectasis when the chest was closed, HPV was less effective during atelectasis than during hypoxia.
在两组麻醉的闭胸犬中测量了胸膜内压对肺不张和低氧血症引起的低氧性肺血管收缩（HPV）反应的影响。右肺持续用100%氧气通气。左肺最初用100%氧气通气（高氧），但随后经历再吸收性肺不张（肺不张；第一组）或用低氧气体混合物通气（低氧血症；第二组）。高氧期间左半侧胸腔的平均胸膜内压为5.4 cmH₂O，但随着左肺肺不张，在15分钟时显著降至-3.8 cmH₂O，在90分钟时降至-4.2 cmH₂O。静脉血掺杂（%VA）从高氧期间的10.3%显著增加到左肺肺不张15分钟时的33.2%和90分钟时的34.6%。然而，在左肺仍处于肺不张状态下开胸后，%VA显著降至25.4%。对于低氧血症组，%VA从高氧期间的9.2%显著增加到左肺低氧15分钟时的29.9%和90分钟时的25.1%。HPV使血流从肺不张肺和低氧肺分流。然而，由于在胸腔关闭时左肺再吸收性肺不张期间产生的胸膜内负压，HPV在肺不张期间比在低氧血症期间效果更差。
