Shah S S, Leonard E F
Ann Biomed Eng. 1983;11(2):67-81. doi: 10.1007/BF02367492.
Evaluation of blood oxygenators using whole blood is inconvenient and expensive, although it is the ultimate preclinical test. Sodium sulfite solutions have advantages over blood for studying oxygen uptake: They are inexpensive, fewer variables need control, and deoxygenation is unnecessary. Assays and interpretation of results are easy. The kinetics of sulfite oxidation must be fast and the concentration of sulfite must be low to emulate oxygen uptake by blood. The kinetics were studied yielding a first order rate constant in sulfite, zero order in oxygen, of 740/min. Limitations of the technique were evaluated using the experimental rate constant and an adaptation of Lightfoot's approximation. While the reaction of hemoglobin is reversible and essentially instantaneous, that for sulfite is irreversible and finite. Thus if the approach to saturation is not monotonic or if the mass transfer resistance is significantly lowered, e.g., when blood film thicknesses are thinner than a few hundred microns, deviations may occur. Two TMO oxygenators and several prototypes were tested, with both sulfite and bovine blood. Uptakes of oxygen were comparable and the effect of parameter variations were similar. The use of sulfite for early evaluation of oxygenators is concluded to be very useful.
使用全血评估血液氧合器既不方便又昂贵，尽管这是最终的临床前测试。亚硫酸钠溶液在研究氧气摄取方面比血液具有优势：它们价格便宜，需要控制的变量较少，并且无需脱氧。测定和结果解释都很容易。亚硫酸盐氧化的动力学必须很快，亚硫酸盐的浓度必须很低才能模拟血液对氧气的摄取。对动力学进行了研究，得出亚硫酸盐的一级速率常数、氧气的零级速率常数为740/分钟。使用实验速率常数和对莱特富特近似法的一种改编来评估该技术的局限性。虽然血红蛋白的反应是可逆的且基本上是瞬时的，但亚硫酸盐的反应是不可逆的且是有限的。因此，如果达到饱和的方法不是单调的，或者传质阻力显著降低，例如当血膜厚度小于几百微米时，可能会出现偏差。使用亚硫酸盐和牛血对两种TMO氧合器和几个原型进行了测试。氧气摄取量相当，参数变化的影响也相似。得出结论，使用亚硫酸盐对氧合器进行早期评估非常有用。
