Mertzlufft F O, Brandt L, Nick D
Klinik für Anästhesiologie, Johannes-Gutenberg-Universität Mainz.
Anasth Intensivther Notfallmed. 1989 Feb;24(1):27-36.
Adequate respiratory monitoring should immediately indicate deteriorations of arterial oxygen status, e.g. hypoxia (paO2-decrease [mmHg]), hypoxaemia (caO2-decrease [ml/dl]) and hypoxygenation (saO2-decrease [%]). These alterations have been detected in the early postanaesthetic period only by the classical clinical criterias cyanosis and tachycardia. Therefore, O2-application often is recommended for the first 10 min postoperatively. Nevertheless oxygen therapy as well as discharge from the recovery room both are dependent on the anaesthetist's judgement. It was the aim of this study to evaluate incidence and criterias of postanaesthetic hypoxygenation following balanced anaesthesia with isoflurane and to estimate both the actually most valid parameter (psO2) and the monitoring of choice (pulse oximetry). Postoperative hypoxygenation (psO2 less than 90%) occurred in 36% within the total of 50 patients. A correlation between hypoxygenation and sex, age, smoking habits and ASA-classification (groups I and II) could not be detected. In conclusion postanaesthetic hypoxygenation must be considered as being influenced by a widespread number of different factors. It's occurrence therefore, seems to be unpredictable. Hypoxygenation can easily be avoided by application of O2 (31/min) over at least 40 min. Cyanosis and tachycardia are not suitable for recognition of hypoxaemia caused by periodically occurring hypoxygenations. With respect to the limitations of the method (measurement of arterial O2-saturation in peripheral circulation using pulse wave as an inflow indicator of arterial blood into the capillary bed; increased Hb-derivative concentrations, e.g. COHb), pulse oximetry for estimation of partial O2-saturation (psO2) seems to be the respiratory monitoring of choice in the early postoperative period. In that sense it is superior to pO2 but inferior to saO2 and caO2.
充分的呼吸监测应能立即显示动脉氧状态的恶化，例如低氧血症（动脉血氧分压[mmHg]降低）、低氧血症（动脉血氧含量[ml/dl]降低）和氧合不足（动脉血氧饱和度[％]降低）。这些变化在麻醉后早期仅通过经典的临床标准如发绀和心动过速才能检测到。因此，通常建议在术后最初10分钟内给予氧气。然而，氧疗以及从恢复室出院均取决于麻醉医生的判断。本研究的目的是评估异氟烷平衡麻醉后麻醉后低氧血症的发生率和标准，并估计实际最有效的参数（脉搏血氧饱和度）和首选监测方法（脉搏血氧饱和度测定）。在总共50例患者中，有36％发生了术后低氧血症（脉搏血氧饱和度低于90％）。未发现低氧血症与性别、年龄、吸烟习惯和ASA分级（I组和II组）之间存在相关性。总之，麻醉后低氧血症必须被视为受多种不同因素影响。因此，其发生似乎是不可预测的。通过至少40分钟给予氧气（3L/分钟），可以很容易地避免低氧血症。发绀和心动过速不适用于识别由周期性低氧血症引起的低氧血症。考虑到该方法的局限性（使用脉搏波作为动脉血流入毛细血管床的流入指标来测量外周循环中的动脉血氧饱和度；血红蛋白衍生物浓度增加，例如碳氧血红蛋白），脉搏血氧饱和度测定法用于估计部分氧饱和度（脉搏血氧饱和度）似乎是术后早期呼吸监测的首选方法。从这个意义上说，它优于动脉血氧分压，但不如动脉血氧饱和度和动脉血氧含量。
