Knichwitz G, Mertes N, Kuhmann M
Klinik und Poliklinik für Anaesthesiologie und operative Intensivmedizin, Westf. Wilhelms-Universität Münster, Germany.
Anaesthesia. 1995 Jun;50(6):532-4. doi: 10.1111/j.1365-2044.1995.tb06047.x.
The measurement of gastric intramucosal pH serves as a non-invasive technique for early detection of gastrointestinal ischaemia in critically ill patients. The method is based on the determination of the partial pressure of carbon dioxide in a 0.9% saline solution using a standard blood gas analyser. However, the use of standard blood gas analysers leads to an underestimation of carbon dioxide partial pressure in saline. Instrumental biases of six blood gas analysers were investigated using either a saline or a phosphate-buffered solution. Both test solutions were equilibrated with five defined carbon dioxide concentrations. Each blood gas analyser underestimated this defined partial pressure of carbon dioxide with a bias between -3.7% and -57.5% if saline was used. The phosphate-buffered solution considerably improved instrumental precision, resulting in biases between +2.7% and -17.6% Thus, a phosphate-buffered solution increases the accuracy of gastric intramucosal pH measurement.
测量胃黏膜内pH值是一种用于早期检测危重症患者胃肠道缺血的非侵入性技术。该方法基于使用标准血气分析仪测定0.9%盐溶液中的二氧化碳分压。然而，使用标准血气分析仪会导致盐水中二氧化碳分压的低估。使用盐水或磷酸盐缓冲溶液研究了六种血气分析仪的仪器偏差。两种测试溶液均与五种定义的二氧化碳浓度平衡。如果使用盐水，每种血气分析仪对这种定义的二氧化碳分压的低估偏差在-3.7%至-57.5%之间。磷酸盐缓冲溶液显著提高了仪器精度，偏差在+2.7%至-17.6%之间。因此，磷酸盐缓冲溶液提高了胃黏膜内pH值测量的准确性。
