经食管监测脉搏氧饱和度在开胸手术中的应用研究

Application of trans-esophageal arterial oxygen saturation monitoring in thoracotomy

摘要:

目的  观察胸科手术中经食管监测脉搏氧饱和度（SteO2）的敏感性及准确性。方法  选择80例择期行全身麻醉下开胸手术单肺通气患者，诱导插管后于食管中下段放置带气囊氧饱和度探头并监测SteO2，将气囊充气，按不同压力作用于探测部位食管壁，分为C组（0 cmH2O）、S1组（20 cmH2O）、S2组（40 cmH2O）、S3组（60 cmH2O），每组20例患者。所有患者采用降低分钟通气量（VT=6 ml/kg、RR=10次/min）及吸入30%氧浓度方式，观察各组血氧饱和度（SpO2）及SteO2下降至95%、91%的时间，同时测动脉血氧饱和度（SaO2），记录各组SteO2信号干扰次数和并发症。结果  所有患者成功监测SteO2信号。与C组（气囊未充气）比较，气囊充气后的S1、S2和S3组信号干扰减少（P <0.05）。在发生低氧时，各组SteO2提前发生SpO2下降，C组SteO2降至95%表现最灵敏，与S2、S3组比较差异有统计学意义（P <0.05），C、S1组SteO2降至91%，与S2、S3组比较差异有统计学意义（P <0.05）。以SaO2作为标准值，当SpO2 95%时，C组SteO2偏差发生率较S2、S3组增加（P <0.05），SpO2 91%时，C、S1组SteO2偏差发生率较S2、S3组增加（P <0.05）。结论  SteO2可作为一种血氧饱和度监测途径，更早地对低氧的发生进行预警。因为不同食管壁表面压力对测得的结果有影响，为排除食管壁内静脉血流干扰，气囊压力在40 cmH2O时较合理，且测得的数值接近于SaO2。

Abstract:

Objective To observe the sensitivity and accuracy of trans-esophageal monitoring of pulse oxygen saturation (SteO2) in thoracic operation. Methods In 80 patients undergoing selective thoracic operation with general anesthesia and one lung ventilation, a self-made air-bag SteO2 probe was placed in the middle and distal segments of esophagus after induced intubation, the balloon was inflated. According to different pressure on the detection part of the esophageal wall, the patients were randomly divided into group C (pressure of balloon = 0 cm H2O), group S1 (20 cm H2O), group S2 (40 cm H2O) and group S3 (60 cm H2O) with 20 patients in each group. In all the patients minute ventilation was decreased (VT = 6 ml/kg, RR = 10 /min) and 30% oxygen was inhaled. The time of SpO2 and SteO2 decreasing to 95% and 91% was record, and SaO2 was detected at the same time. The number of SteO2 signal interference and complications were recorded. Results SteO2 signals were successfully monitored in all the patients. Compared with the group C (no air-bag inflation), signal interference significantly reduced after air-bag inflation in the groups S1, S2 and S3 (P < 0.05). In hypoxic condition, in all the groups the drop of SteO2 was ahead of SpO2 drop. When SteO2 in the group C dropped to 95%, it was most sensitive in warning de-saturation compared with the groups S2 and S3 (P < 0.05); at the time when SteO2 in the groups C and S1 dropped to 91%, it was significantly different form that of the groups S2 and S3 (P < 0.05). However, SaO2 as the reference standard, the incidence of deviation of SteO2 in the group C significantly increased compared to that in the groups S2 and S3 when SpO2 was 95% (P < 0.05); it also significantly increased in the groups C and S1 compared to that in the groups S2 and S3 when SpO2 was 91% (P < 0.05). Conclusions SteO2 monitoring could be used as an approach for oxygen saturation monitoring which can give earlier warning of hypoxia. Since different pressure on the surface of esophageal wall has influence on the measured results, for the exclusion of interference by esophageal intramural venous flow, the pressure of air-bag at 40 cm H2O is reasonable when SteO2 value is close to SaO2.