From R P, Scamman F L
Department of Anesthesia, University of Iowa College of Medicine, Iowa City 52242.
Anesth Analg. 1988 Sep;67(9):884-6.
An accurate high-frequency response is mandatory when end-tidal CO2 (PETCO2) is monitored during pediatric general anesthesia. The purpose of this study was to assess the accuracy of six infrared-based capnometers and one multiplexed mass spectrometer available at our institution at increasing frequency. Capnometers studied were the Datascope Accucap, Hewlett-Packard 47210A capnometer, Narkomed 3 Capnomed, Novametrix Capnogard model 1250, Perkin-Elmer Advantage, Puritan-Bennett Datex CO2 monitor, and Traverse Medical Monitor model 2200 capnometer. Changes in CO2 concentration were generated by a solenoid valve switching between 100% O2 and 7% CO2 in O2. Frequencies, 8-101 cycles/min were chosen to stimulate a range that might be generated by children during general endotracheal anesthesia. At every rate the displayed PETCO2 was recorded. Differences in displayed PETCO2 from known CO2 ranged from -16.4 to +6.6. At or below frequencies of 31 cycles/min, four capnometers overreported and three underreported PETCO2. At frequencies above 31 cycles/min, six capnometers underreported and one overreported PETCO2. Errors may be clinically significant if they influence ventilator settings for patients.
在小儿全身麻醉期间监测呼气末二氧化碳（PETCO2）时，准确的高频响应至关重要。本研究的目的是评估我院现有的六种基于红外线的二氧化碳监测仪和一台多路复用质谱仪在频率增加时的准确性。所研究的二氧化碳监测仪有Datascope Accucap、惠普47210A二氧化碳监测仪、Narkomed 3 Capnomed、诺瓦美克斯Capnogard 1250型、珀金埃尔默Advantage、普瑞美达-贝内特Datex二氧化碳监测仪以及Traverse Medical Monitor 2200型二氧化碳监测仪。通过电磁阀在100%氧气和含7%二氧化碳的氧气之间切换来产生二氧化碳浓度的变化。选择8 - 101次/分钟的频率来模拟小儿在全身气管内麻醉期间可能产生的频率范围。在每个频率下记录显示的PETCO2。显示的PETCO2与已知二氧化碳之间的差异范围为 - 16.4至 + 6.6。在31次/分钟及以下的频率时，四种二氧化碳监测仪高估了PETCO2，三种低估了PETCO2。在高于31次/分钟的频率时，六种二氧化碳监测仪低估了PETCO2，一种高估了PETCO2。如果这些误差影响患者的呼吸机设置，可能具有临床意义。
