经食管监测主动脉血氧饱和度及其临床意义

Clinical significance of transesophageal arterial oxygen saturation monitoring

目的探讨经食管监测主动脉血氧饱和度(SteO2)的敏感性与精确性。方法45例择期手术患者,全麻气管插管后放置自制SteO2装置入食管下段。SteO2和脉搏血氧饱和度(SpO2)停止机械通气和稳定后供氧,SteO2从100%降到90%后立即纯氧吸入,实时动脉血气监测,观察相同时点SteO2和SpO2的变化。结果(1)SteO2与动脉血氧饱和度(SaO2)有良好的相关性(r=0.9514);SteO2与SaO2比较,相对与绝对偏差分别是1.7%和1.2%。(2)SteO2下降变化早于SpO2,提前(109.8±19.3)s(P<0.01)。结论经食管连续监测SteO2具有可行性。在预警条件下,急性缺氧时SteO2较SpO2更早报警。SteO2可以作为无创连续SaO2另一监测手段。

Objective To study the sensitivity and accuracy of transoesophageal descending aortic oximetry（SteO2） as a new monitoring site. Methods A total of 45 surgical patients undergoing general anesthesia were included in this study. A disposable oximetry probe that was designed by ourselve was placed in the lower segment of the esophagus to monitor SteO2. After the signals and readings of SteO2 and SpO2 were stable, the ventilator was disconnected and the changes of SteO2 and SpO2 were recorded until SteO2 reached to 90 %, and a few blood samples were taken for SaO2 measurements during this period of time. Then ventilator was re-connected and the recovery rates of SteO2 and SpO2 were observed. Results Correlation coefficient was 0.9514 with SteO2 to SaO2. Compared with SaO2, the relative deviation of SteO2 was 1.7 % and the absolute deviation of SteO2 was 1.2 %. When the ventilator disconnected, SteO2 dropped by（109.8±19.3） s earlier than SpO2 （P〈0. 01）. Conclusion The correlation is better between SteO2 and SaO2. Tranesophageal SteO2 monitoring is sensitive, which responds faster and closer to SaO2 than SpO2 measurements. The results indicate that SteO2 monitoring can be an alternative way of oxygen saturation monitoring.