Bardoczky G I, Szegedi L L, d'Hollander A A, Moures J M, de Francquen P, Yernault J C
Department of Anesthesiology, Erasme University Hospital, Free University of Brussels, Belgium.
Anesth Analg. 2000 Jan;90(1):35-41. doi: 10.1097/00000539-200001000-00008.
We compared the effects of position and fraction of inspired oxygen (F(IO)2) on oxygenation during thoracic surgery in 24 consenting patients randomly assigned to receive an F(IO)2 of 0.4 (eight patients, Group 0.4), 0.6 (eight patients, Group 0.6), or 1.0 (eight patients, Group 1.0) during the periods of two-lung (TLV) and one-lung ventilation (OLV) in the supine and lateral positions. TLV and OLV were maintained while the patients were first in the supine and then in the lateral position for 15 min each. Thereafter, respiratory mechanical data were obtained, and arterial blood gas samples were drawn. Pao2 decreased during OLV compared with TLV in both the supine and lateral positions. In all three groups, Pao2 was significantly higher during OLV in the lateral than in the supine position: 101 (72-201) vs 63 (57-144) mm Hg in Group 0.4; 268 (162-311) vs 155 (114-235) mm Hg in Group 0.6; and 486 (288-563) vs 301 (216-422) mm Hg in Group 1.0, respectively (P < 0.02, Wilcoxon's signed rank test). We conclude that, compared with the supine position, gravity augments the redistribution of perfusion as a result of hypoxic pulmonary vasoconstriction, when patients are in the lateral position, which explains the higher Pao2 during OLV.
This study compares oxygenation during thoracic surgery during periods of two-lung and one-lung ventilation with patients in the supine and lateral positions when using three different fraction of inspired oxygen values. Arterial oxygen tension was decreased in all three groups during one-lung ventilation in comparison with the two-lung ventilation values, but the decrease was significantly less in the lateral, compared with the supine position.
我们比较了24名同意参与研究的患者在胸外科手术期间，在双肺通气（TLV）和单肺通气（OLV）阶段，仰卧位和侧卧位时吸入氧分数（F(IO)2）的不同水平及其对氧合的影响。这24名患者被随机分为三组，每组8人，分别在TLV和OLV阶段接受F(IO)2为0.4（0.4组）、0.6（0.6组）或1.0（1.0组）的通气，并分别在仰卧位和侧卧位各维持15分钟。之后，获取呼吸力学数据，并采集动脉血气样本。在仰卧位和侧卧位时，与TLV相比，OLV期间动脉血氧分压（Pao2）均降低。在所有三组中，OLV期间侧卧位时的Pao2均显著高于仰卧位：0.4组分别为101（72 - 201）mmHg和63（57 - 144）mmHg；0.6组分别为268（162 - 311）mmHg和155（114 - 235）mmHg；1.0组分别为486（288 - 563）mmHg和301（216 - 422）mmHg（P < 0.02，Wilcoxon符号秩检验）。我们得出结论，与仰卧位相比，当患者处于侧卧位时，重力作用会增强因缺氧性肺血管收缩导致的灌注再分布，这就解释了OLV期间Pao2较高的原因。
本研究比较了在胸外科手术期间，当使用三种不同的吸入氧分数值时，患者在仰卧位和侧卧位的双肺通气和单肺通气阶段的氧合情况。与双肺通气值相比，所有三组在单肺通气期间动脉氧分压均降低，但与仰卧位相比，侧卧位时降低幅度明显更小。
