吸入气与呼气末氧浓度差和呼气末二氧化碳在全麻急性低通气时的变化规律

吸入气与呼气末氧浓度差和呼气末二氧化碳在全麻急性低通气时的变化规律 吸入气与呼气末氧浓度差和呼气末二氧化碳在全麻急性低通气时的变化规律 作者: 韩柏秀 黄科昌 王秀莹 于天英 【关键词】 全身麻醉 【摘要】 目的 观察N 2 O-O 2 静吸复合全麻时急性低通气恢复正常后I-EO 2 和ETCO 2 变化规律的比较。 方法 20例N 2 O-O 2 静吸复合全麻患者，术中机械通气，FiO 2 =0.35。观察由正常V T (10ml/kg)调至4ml/kg后15min和迅速调回至正常后15min内各指标的变化。 结果 低通气后I-EO 2 、ETCO 2 、BP和HR均明显增加。恢复正常通气后HR、BP和ETCO 2 于15min内先后恢复正常，而I-EO 2 仍高出低通气前的17.2%。而且，各观察时点I-EO 2 的变化率均高于ETCO 2 的变化率(P0.01)。 结论 与ETCO 2 相比，I-EO 2 虽能更早地反映通气量降低，但却不能及时反映通气量的恢复。 关键词 全身麻醉 通气 吸入气与呼气末氧浓度差 呼气末二氧化碳 Changes of inspiratory to end-tidal oxygen concentration difference and end-tidal carbon dioxide during acute hypoventilation Han Boxiu，Huang Kechang，Wang Xiuying，et al. Affiliated Hospital of Weifang Medical College，Weifang26103 Objective To pare the regulation of the changes of inspiratory to end- 1. 【Abstract】 tidal oxygen concen-tration difference(I-EO 2 )and end-tidal carbon dioxide(ETCO 2 )after the correction of acute hypoventilation during intravenous inhalation anesthesia.Methods Twenty patients underwent N 2 O-O 2 intravenous inhalation anesthesia were received volume-controlled mechanical ventilation with an FiO 2 =0.35.After a period of normal ventilation with V T =10ml/kg，acute hypoventilation was induced with V T =4ml/kg for15minutes followed by an correction with nor-mal ventilation.I-EO 2 ，ETCO 2 ，BP，HR and SpO 2 were observed for15minutes for each process.Results During the period of hypoventilation，there were significant increases for BP and HR，especially for I-EO 2 and ETCO 2 .Fifteen minutes after the correction of hypoventilation，HR，BP and ETCO 2 recovered to normal level，while I-EO 2 were still higher than that prior to acute hypoventilation.Morever，the changes of I-EO 2 were much higher than those of ETCO 2 at all these measurements.Conclusion In parison with ETCO 2 ，I-EO 2 will reflex the decrease of ventilation ear-lier，but not the recovery of ventilation. Key words general anesthesia ventilation inspiratory to end-tidal oxygen concentration difference end-tidal carbon dioxide 在麻醉和危重病医学中，呼吸功能监测是一项重要的内容。我们以往的研究明，吸入气与呼气末氧浓度差(inspiratory to end-tidal oxygen concentration difference，I-EO 2 )是监测通气功能的一种良好指标，在监测通气功能降低时其敏感性远远大于呼气末二氧化碳(ETCO 2 )和脉搏血氧饱和度(SpO 2 ) 的研究指出，N 2 O-O 2 麻醉时，I-EO 2 受N 2 O摄取的影响。我们过去的研究表明，机械通气潮气量降低时，I-EO 2 对通气改变的敏感性受FiO 2 的影响，FiO 2 越低，低通气时I-EO 2 改变的敏感性越大 ,2, 。故本研究以相同 的N 2 O-O 2 浓度为前提，并在N 2 O的吸、呼浓度基本达平衡时才进入研究。在此条件下，当调节正常通气量至潮气量为4ml/kg的急性低通气状态并维持15min时，ETCO 2 上升58.9%，I-EO 2 上升124.9%，这与我们以前的部分研究结果 ,2, 极为相似。说明本研究结果重复。