食管癌术中硬膜外阻滞对单肺通气期间动脉氧合的影响∗

摘要

目的：探讨食管癌手术采取全麻复合硬膜外阻滞麻醉时对单肺通气（ OLV）期间动脉氧合的影响。方法选择60例行经左胸食管癌根治术患者（ ASAIII级），随机分为静脉全麻复合硬膜外阻滞麻醉组（ A组，30例）和仅静脉全麻组（ B组，30例）。两组患者分别于OLV前（ T1）、OLV 15min（ T2）、OLV 30min（ T3）抽取桡动脉血和混合静脉血行血气分析，计算通气/血流比（Qs/Qt）值。结果在T2和T3时，A组氧分压（PaO2）分别为（219�3±48�2）mmHg和（174�7±37�6）mmHg，显著低于B组的（268�1±81�2）mmHg和（221�6±87�0）mmHg。在OLV期间，A组的Qs/Qt显著高于B组（P＜0�05），各时间点A组血压均显著低于B组（ P＜0�05）。结论全麻复合硬膜外阻滞麻醉时会引起食管癌患者术中血压下降，而且会引起OLV期间肺内分流的增加和氧分压的降低。%Objective To study the effects of thoracic epidural anesthesia(TEA) with bupivacaine on oxygenation, shunt fraction during one-lung ventilation( OLV) . Methods Sixty patients who had prolonged periods of OLV for elective thoracic surgery for esophageal cancer were randomized into two groups. Thirty patients ( group A) were anesthetized with propofol/atracurium/epidural thoracic bupivacaine 0�5%. In another 30 patients ( group B) , fentanyl/propofol/atracurium anesthesia was used. A double-lumen en-dotracheal tube was inserted, and mechanical ventilation with 100% oxygen was used during the entire study. Arterial and venous blood gases were recorded before surgery in a lateral position with two-lung ventilation, 15 and 30 min after OLV ( OLV+15 and OLV+30, respectively) in all patients. PaO2, venous central oxygen tension, arterial and central venous oxygen saturation, venous admixture per-centage (Qs/Qt) were measured. Results The mean values for PaO2 during OLV in the group A after 15min with (219�3±48�2)mm-Hg and 30min with ( 174�7 ± 37�6 ) mmHg were significantly lower compared with the group B ( 268�1 ± 81�2mmHg and 221�6 ± 87�0mmHg, respectively) . Furthermore, Qs/Qt was significantly increased in group A during OLV. And, blood pressure was signifi-cantly lower in group A during surgery. There were no significant differences. Conclusion We conclude that using the TEA regimen is associated with a lower PaO2 and a larger intrapulmonary shunt during OLV than with total anesthesia alone.