Cheriyan G, Helms P, Paky F, Marsden D, Chiu M C
Arch Dis Child. 1986 Jul;61(7):652-6. doi: 10.1136/adc.61.7.652.
Transcutaneous and arterial carbon dioxide were measured simultaneously in 57 children (age range 10 days to 14.3 years) undergoing intensive care. All were haemodynamically stable at the time of study. Mean calibration time with 5 and 10% carbon dioxide was 43 (range 38-58) minutes and mean arterialisation time was 10.5 (range 3-30) minutes. Duplicate hourly arterial samples over a four hour period showed that transcutaneous: arterial carbon dioxide correlation was independent of electrode temperatures over the range 42-44 degrees C and was independent of child age. One and a half hours after electrode placement transcutaneous carbon dioxide (kPa) = arterial carbon dioxide X 1.41 + 0.02. Use of a simple ratio (arterial carbon dioxide = transcutaneous carbon dioxide/1.40) resulted in a mean estimate of arterial carbon dioxide within 3% of the actual value with coefficients of variation of 11 and 15% at 1.5 and 4.5 hours, respectively. For prediction of arterial carbon dioxide 95% confidence limits around the regression mean rose from +/- 1.04 kPa (7.8 mm Hg) at 1.5 hours to +/- 1.56 (11.7 mm Hg) at 4.5 hours. Baseline drift was more than +/- 0.67 kPa (5 mm Hg) during 22% of the studies. For a drift of less than 0.67 kPa 95% confidence limits were 0.87 and 1.12 kPa, respectively. Arterial carbon dioxide can be estimated with clinically acceptable tolerances from surface electrodes operating at temperatures between 42-44 degrees C. Improved electrode stability and speed of calibration should make this a valuable monitoring technique.
对57名接受重症监护的儿童（年龄范围为10天至14.3岁）同时进行经皮和动脉血二氧化碳测量。研究时所有儿童血流动力学均稳定。用5%和10%二氧化碳进行平均校准时间为43（范围38 - 58）分钟，平均动脉化时间为10.5（范围3 - 30）分钟。在4小时期间每小时采集两份动脉样本，结果显示经皮血二氧化碳与动脉血二氧化碳的相关性在42 - 44摄氏度范围内与电极温度无关，且与儿童年龄无关。电极放置1.5小时后，经皮血二氧化碳（kPa）=动脉血二氧化碳×1.41 + 0.02。使用简单比值（动脉血二氧化碳 = 经皮血二氧化碳/1.40）得出的动脉血二氧化碳平均估计值在实际值的3%以内，在1.5小时和4.5小时时变异系数分别为11%和15%。对于动脉血二氧化碳的预测，回归均值周围的95%置信区间从1.5小时时的±1.04 kPa（7.8 mmHg）升至4.5小时时的±1.56（11.7 mmHg）。在22%的研究中基线漂移超过±0.67 kPa（5 mmHg）。对于小于0.67 kPa的漂移，95%置信区间分别为0.87和1.12 kPa。在42 - 44摄氏度温度下运行的表面电极可在临床可接受的公差范围内估计动脉血二氧化碳。改进电极稳定性和校准速度将使这成为一种有价值的监测技术。
