全麻下单肺通气对肺功能的影响

Influence of one-lung ventilation on respiratory function during general anesthesia

目的 探讨单肺通气状况的最佳呼吸方式。方法 60例 ASA ～ 级开胸病人单肺麻醉时 ,在分钟通气量设定的条件下 ,随着吸气时间相对延长 (通过降低呼吸频率和吸∶呼比值 )的不同通气条件变化 ,对单肺功能和血气分析的影响进行了临床研究。结果 单肺通气时 ,在呼吸频率 =12次 /分 ,吸∶呼比值 =1∶ 1时 ,通气侧肺顺应性、实际分钟通气量和脉搏血氧饱和度明显改善 ,血气结果最佳 ,与双肺通气相比较无显著性差异 ( P>0 .0 5 ) ;气道压力显著降低 ,与单肺通气其它通气条件相比较有显著性降低 ( P<0 .0 5 )。但过分降低呼吸频率 ( RR<10次 /分 )达到的效果会适得其反。结论 在单肺通气使用麻醉呼吸器时 ,相对降低呼吸频率 ( RR=12次 /分 )、相对延长吸气时间 ( I∶ E=1∶ 1.5 ) ,可达到提高肺顺应性和通气量 ,降低气道压力 。

Objective To study the proper way of one lung ventilation (OLV) during general anesthesia.Methods Sixty patients ASA grade I II ,scheduled for intra thoracic surgical procedures were enrolled in the study.After anesthesia induction ,the left sided double lumen endobronchial tube was intubated.Under the lateral decubitus position,the ventilation was controlled at different levels of respiratory rate (RR) and inspiratory to expiratory ratio(I∶E) with a setting value of minute volume of ventilatiially sequentially: two lung ventilation with RR 15 breaths/min and I∶E=1∶2 (phase i), OLV with RR 15 breaths/min and I∶E=1∶2 (phase Ⅱ),OLV with RR 15 breaths/min and I∶E=1∶1.5(phase Ⅲ),OLV with RR 12 breaths/min and I∶E=1∶2 (phase Ⅳ),OLV with RR 12 breaths/min and I∶E=1∶1.5 Phase Ⅴ),OLV with 12 breaths/min and I∶E=1∶1.0 (phase Ⅵ) and OLV with RR 10 breaths/min and I∶E=1∶1.5 (phase Ⅶ). Respiratory parameters and arterial blood gases were measured at the 7 phases mentioned above. Results As compared with those at phase Ⅰ,the airway pressure increased significantly at other phases (P< 0.05 0.01),respiratory compliance remained unchanged only at phases Ⅴ and Ⅵ(P>0.05),but decreased significantly at the rest phases (P<0.05), the actual minute ventilation was kept stable at phase Ⅴ (P>0.05) and reduced markedly at other phases (P<0.05), PaO 2 and PaCO 2 was kept unchanged (P>0.05),however PaO 2 was depressed and PaCO 2 rose obviously at other phases ( P< 0.05 ). Conclusion The RR 12 breaths/min and I∶E=1∶1.5 can help to improve the respiratory function during one lung ventilation.