Department of Integrative Physiology, University of Colorado, Boulder, Colorado 80309-0354, USA.
Scand J Clin Lab Invest. 2011 Oct;71(6):523-8. doi: 10.3109/00365513.2011.589008. Epub 2011 Jul 6.
Total haemoglobin mass (Hb(mass)) can be assessed with low measurement error using carbon monoxide (CO) rebreathing. However, variability in measurement error of Hb(mass) has been reported across laboratories and it has previously been suggested that CO leaks contribute to this variability. As a result of employing a standardized leak monitoring procedure using two CO detectors, we were able to retrospectively examine the impact of CO leaks on Hb(mass) values from past test-retest studies in our laboratory using the optimized CO rebreathing method. Test-retest data were collected to determine measurement error, with subjects tested twice within 5 days. Test-retest data were placed into separate categories based on magnitude and duration of CO leak observed during one of the two tests. The No Leak category contained test-retest data in which no leak occurred during either test. The Minor Leak category contained test-retest data in which one of the tests had a CO leak of magnitude less than 30 ppm and less than 5 seconds duration, whereas the Major Leak category included test-retest data in which a leak greater than this magnitude or duration occurred. Measurement error was lowest in the No Leak category (1.9%; 95%CI: 1.6-2.3%; n = 56), approximately doubled in the Minor Leaks category (3.6%; 95%CI: 2.6-6.1%; n = 13), and dramatically increased in the Major Leaks category (9.3%; 95%CI: 6.3-17.6%; n = 10). We recommend careful monitoring of potential CO leaks using multiple detectors. To minimize measurement error, tests in which any CO leak is detected should be excluded.
总血红蛋白质量 (Hb(mass)) 可以使用一氧化碳 (CO) 再呼吸法以低测量误差进行评估。然而，不同实验室报告的 Hb(mass) 测量误差存在差异，并且之前有人提出 CO 泄漏会导致这种差异。由于采用了使用两个 CO 探测器的标准化泄漏监测程序，我们能够使用优化的 CO 再呼吸法回顾性地检查 CO 泄漏对我们实验室过去的测试-重测研究中 Hb(mass) 值的影响。收集测试-重测数据以确定测量误差，让受试者在 5 天内测试两次。根据在两次测试中的一次中观察到的 CO 泄漏的幅度和持续时间，将测试-重测数据分为单独的类别。无泄漏类别包含在两次测试中均未发生泄漏的测试-重测数据。轻微泄漏类别包含在其中一次测试中 CO 泄漏幅度小于 30 ppm 且持续时间小于 5 秒的测试-重测数据，而主要泄漏类别则包括泄漏幅度大于此或持续时间大于此的测试-重测数据。在无泄漏类别中，测量误差最低（1.9%；95%CI：1.6-2.3%；n = 56），在轻微泄漏类别中大约增加一倍（3.6%；95%CI：2.6-6.1%；n = 13），在主要泄漏类别中急剧增加（9.3%；95%CI：6.3-17.6%；n = 10）。我们建议使用多个探测器仔细监测潜在的 CO 泄漏。为了最小化测量误差，应排除检测到任何 CO 泄漏的测试。
