Satoh D, Sato M, Kaise A, Hagiwara Y, Saishu T, Hashimoto Y
Department of Anesthesiology, Tohoku University School of Medicine, Sendai, Japan.
Acta Anaesthesiol Scand. 1998 Nov;42(10):1145-8. doi: 10.1111/j.1399-6576.1998.tb05267.x.
Hypoxic pulmonary vasoconstriction has an important role in human one-lung ventilation (OLV) in the lateral decubitus position under general anesthesia. During OLV, inhalational anesthesia may inhibit hypoxic pulmonary vasoconstriction and the decrease in arterial oxygenation. We studied the effect of isoflurane administration on arterial oxygen tension in chronic obstructive pulmonary disease patients.
Ten patients who had thoracoscopic laser ablation of bullous emphysema were studied. Patients received 2% isoflurane in oxygen from induction until the first 20 min of OLV in the lateral decubitus position, then were switched to 1% isoflurane lasting 20 min and next were switched to 0.5% isoflurane lasting 20 min. After each 20-min inhalation, pulmonary and hemodynamic parameters were measured. The given concentrations for isoflurane were merely vapor meter concentrations.
PaO2/FIO2, Qs/Qt respiratory rate peak inspiratory pressure and PaCO2 showed no significant changes at each point of isoflurane. Expiratory tidal volume significantly decreased (P < 0.05) with 0.5% isoflurane compared to that with 2% isoflurane. Cardiac output, mean arterial pressure, mean pulmonary arterial pressure, systemic vascular resistance and pulmonary vascular resistance showed no significant changes at each point of isoflurane.
In patients with pulmonary emphysema, arterial oxygenation is not affected by low isoflurane concentration during OLV in the lateral decubitus position.
在全身麻醉下侧卧位单肺通气（OLV）时，低氧性肺血管收缩在人体中起重要作用。在OLV期间，吸入麻醉可能会抑制低氧性肺血管收缩以及动脉氧合的降低。我们研究了异氟烷给药对慢性阻塞性肺疾病患者动脉血氧张力的影响。
对10例接受胸腔镜下激光消融治疗大疱性肺气肿的患者进行研究。患者从诱导期开始至侧卧位OLV的前20分钟接受2%异氟烷与氧气混合吸入，然后切换至1%异氟烷持续20分钟，接着再切换至0.5%异氟烷持续20分钟。每次吸入20分钟后，测量肺部和血流动力学参数。所给异氟烷浓度仅为挥发罐浓度。
在异氟烷各阶段，动脉血氧分压/吸入氧分数值（PaO2/FIO2）、分流率（Qs/Qt）、呼吸频率、吸气峰压和动脉血二氧化碳分压（PaCO2）均无显著变化。与2%异氟烷相比，0.5%异氟烷时呼气潮气量显著降低（P<0.05）。在异氟烷各阶段，心输出量、平均动脉压、平均肺动脉压、体循环血管阻力和肺血管阻力均无显著变化。
对于肺气肿患者，侧卧位OLV期间低浓度异氟烷不会影响动脉氧合。
