Department of Anesthesiology and Translational Neuroscience Center, West China Hospital, Sichuan University, Chengdu 610041, China.
Front Med. 2012 Dec;6(4):406-10. doi: 10.1007/s11684-012-0217-3. Epub 2012 Oct 2.
The esophagus is perfused directly by prominent arteries and may provide a more consistent tissue source for pulse oximetry. The goal of this study was to evaluate the sensitivity and accuracy of an esophageal pulse oximetry probe on patients during controlled hypoxemia in comparison to measurements obtained with conventional pulse oximetry (SpulseO(2)). Forty-five ASA I-II adult patients were included in this prospective observational study. Nellcor digital oximetric probes were placed on finger tips for SpulseO(2) before anesthesia. After tracheal intubation, an esophageal probe was placed in the lower segment of the esophagus for esophageal oximetric monitoring (SoesO(2)). All patients were disconnected from the breathing circuit to establish a controlled hypoxemia, and were re-connected to the breathing circuit and ventilated with 100% oxygen immediately when SoesO(2) dropped to 90%. Matched SoesO(2) and SpulseO(2) readings were recorded when SoesO(2) measurements were at 100%, 95%, 90% and the lowest reading. The time for SoesO(2) and SpulseO(2) to drop from 100% to 95%, 90% and return to 100% was recorded. Oxygen saturation from arterial blood samples (SartO(2)) was also measured at each time point respectively. The linear correlation coefficient of the regression analysis between SartO(2) and SoesO(2) was 0.954. The mean ± 2SD of the difference was 0.3% ± 4.3% for SoesO(2) vs. SartO(2) and 6.8% ± 5.6% for SpulseO(2) vs. SartO(2) (P < 0.001). The 95% confidence interval for the absolute difference between SoesO(2) and SartO(2) was 0.3% to 0.7% and 6.2% to 7.4% between SpulseO(2) and SartO(2). The time to reach 90% saturation measured with SoesO(2) was approximately 94 seconds earlier than the SpulseO(2) (P < 0.001). In conclusion, SoesO(2) is more accurate and enables earlier detection of hypoxemia when compared to conventional pulse oximetry during hypoxemia for patients undergoing general anesthesia.
食管由明显的动脉直接灌注，可为脉搏血氧饱和度提供更一致的组织来源。本研究的目的是评估在控制低氧血症期间食管脉搏血氧饱和度探头在患者中的敏感性和准确性，并与传统脉搏血氧饱和度（SpulseO（2））的测量值进行比较。本前瞻性观察研究纳入了 45 名 ASA I-II 级成年患者。在麻醉前，Nellcor 数字血氧计探头置于指尖进行 SpulseO（2）测量。气管插管后，将食管探头置于食管下段进行食管血氧饱和度监测（SoesO（2））。所有患者均与呼吸回路断开以建立控制低氧血症，并在 SoesO（2）降至 90%时立即重新连接呼吸回路并使用 100%氧气通气。当 SoesO（2）测量值为 100%、95%、90%和最低读数时，记录匹配的 SoesO（2）和 SpulseO（2）读数。记录从 100%降至 95%、90%和恢复至 100%时 SoesO（2）和 SpulseO（2）的时间。在每个时间点还分别测量动脉血样中的氧饱和度（SartO（2））。SartO（2）和 SoesO（2）之间回归分析的线性相关系数为 0.954。SoesO（2）与 SartO（2）的差值平均值±2SD 为 0.3%±4.3%，SpulseO（2）与 SartO（2）的差值平均值±2SD 为 6.8%±5.6%（P<0.001）。SoesO（2）与 SartO（2）之间绝对差值的 95%置信区间为 0.3%至 0.7%，SpulseO（2）与 SartO（2）之间绝对差值的 95%置信区间为 6.2%至 7.4%。使用 SoesO（2）测量达到 90%饱和度的时间比 SpulseO（2）大约早 94 秒（P<0.001）。总之，与全身麻醉患者低氧血症期间的传统脉搏血氧饱和度相比，SoesO（2）更准确，并能更早地检测到低氧血症。
