Abstract

Total hemoglobin mass (Hb_mass) is routinely assessed in studies by the carbon monoxide (CO) rebreathing. Its clinical application is often hindered due to the consequent rise in carboxyhemoglobin (%HbCO) and the concern of CO toxicity. We tested the reproducibility of the CO rebreathing with a CO dose of 0.5 mL/kg body mass (CO_0.5) compared to 1.5 mL/kg (CO_1.5) and when shortening the CO rebreathing protocol. Therefore, CO rebreathing was performed 1×/day in eight healthy individuals on four consecutive days. On each day, either CO_0.5 (CO_0.5-1 and CO_0.5-2) or CO_1.5 (CO_1.5-1 and CO_1.5-2) was administered. Venous blood samples to determine %HbCO and quantify Hb_mass were obtained prior to, and at 6 (T₆), 8 (T₈) and 10 min (T₁₀) of CO rebreathing. This protocol was tested at sea level and at 2320 m to investigate the altitude-related measurement error. At sea level, the mean difference (95% limits of agreement) in Hb_mass between CO_0.5-1 and CO_0.5-2 was 26 g (–26; 79 g) and between CO_1.5-1 and CO_1.5-2, it was 17 g (–18; 52 g)_. The respective typical error (TE) corresponded to 2.4% (CO_0.5) and 1.5% (CO_1.5), while it was 6.5% and 3.0% at 2320 m. With CO_0.5, shortening the CO rebreathing resulted in a TE for Hb_mass of 4.4% (T₈ vs. T₁₀) and 14.1% (T₆ vs T₁₀) and with CO_1.5, TE was 1.6% and 5.8%. In conclusion, the CO dose and rebreathing time for the CO rebreathing procedure can be decreased at the cost of a measurement error ranging from 1.5-14.1%.

摘要

总血红蛋白质量 (Hb _mass ) 在研究中通过一氧化碳 (CO) 再呼吸进行常规评估。由于碳氧血红蛋白 (%HbCO) 的升高和 CO 毒性的担忧，其临床应用往往受到阻碍。我们测试了 CO 再呼吸的重现性，CO 剂量为 0.5 mL/kg 体重 (CO _0.5 ) 与 1.5 mL/kg (CO _1.5 )相比，并在缩短 CO 再呼吸协议时。因此，连续四天对八名健康个体进行 1 次/天的 CO 再呼吸。每天，CO _0.5（CO _0.5 -1 和 CO _0.5 -2）或 CO _1.5（CO _1.5 -1 和 CO _1.5-2) 进行了管理。在 CO 再呼吸之前和 6 (T ₆ )、8 (T ₈ ) 和 10 分钟 (T ₁₀ ) 时获得静脉血样本，以确定 %HbCO 和量化 Hb_质量。该协议在海平面和 2320 m 处进行了测试，以调查与高度相关的测量误差。在海平面上，CO _0.5 -1 和 CO _0.5 -2之间Hb_质量的平均差异（95% 一致限）为 26 g (–26; 79 g)，CO _1.5 -1 和 CO _1.5 -2之间的平均差异为为 17 克（–18；52 克）_。各自的典型误差 (TE) 对应于 2.4% (CO _0.5 ) 和 1.5% (CO _1.5)，而在 2320 m 处为 6.5% 和 3.0%。使用 CO _{0.5 时}，缩短 CO 再呼吸导致 Hb_质量的TE 为4.4%（T ₈与 T ₁₀）和 14.1%（T ₆与 T ₁₀），使用 CO _{1.5 时}，TE 为 1.6% 和 5.8%。总之，可以减少 CO 再呼吸程序的 CO 剂量和再呼吸时间，代价是测量误差范围为 1.5-14.1%。