Respiratory Investigation Unit, Department of Medicine, Queen's University, Kingston General Hospital, Kingston, Ontario, Canada.
Respir Physiol Neurobiol. 2010 Feb 28;170(2):185-97. doi: 10.1016/j.resp.2009.12.007. Epub 2009 Dec 24.
We quantified the magnitude of within- and between-day, within-subject variability of the ventilatory response to Duffin's modified rebreathing procedure in 20 healthy humans. The P(ETCO2) at which ventilation increased with progressive increases in P(ETCO2) during rebreathing was identified as the ventilatory recruitment threshold (VRT(CO2)); the ventilatory response below and above the VRT(CO2) was taken as an estimate of non-chemoreflex drives to breathe (V(EB)) and chemoreflex sensitivity (V(ES)), respectively. Within- and between-day intraclass correlation coefficients for each of these parameters were >0.60 (range: 0.62-0.93), indicating good-to-excellent test-retest reliability. Within- and between-day, within-subject coefficients of variation for hyperoxic and hypoxic V(EB) (range: 24.6-30.7%) and V(ES) (range: 18.5-32.7%) were relatively high but acceptable, while those for the VRT(CO2) were very small (range: 3.0-3.8%). In conclusion, Duffin's modified rebreathing procedure, in both its hyperoxic and hypoxic form, is a highly reliable tool for measurement of chemoreflex and non-chemoreflex ventilatory control characteristics over short and long periods of time in healthy humans.
我们在 20 名健康人中量化了 Duffin 改良重复呼吸法的呼吸反应的日内和日间、个体内变异性的幅度。在重复呼吸过程中，随着 P(ETCO2)的逐渐增加，通气增加的 P(ETCO2)点被确定为通气募集阈值 (VRT(CO2))；VRT(CO2)以下和以上的通气反应分别被视为非化学感受器驱动呼吸 (V(EB))和化学感受器敏感性 (V(ES))的估计值。这些参数的日内和日间组内相关系数均>0.60（范围：0.62-0.93），表明测试-重测可靠性良好至优秀。在日内和日间，高氧和低氧 V(EB)（范围：24.6-30.7%）和 V(ES)（范围：18.5-32.7%）的个体内变异系数相对较高，但可接受，而 VRT(CO2)的变异系数则非常小（范围：3.0-3.8%）。总之，Duffin 改良重复呼吸法，无论是高氧还是低氧形式，都是一种高度可靠的工具，可用于在健康人群中短时间和长时间内测量化学感受器和非化学感受器通气控制特性。
