Lichtman M A, Cohen J, Young J A, Whitbeck A A, Murphy M
J Clin Invest. 1974 Sep;54(3):501-13. doi: 10.1172/JCI107786.
The interrelationships of arterial oxygen flow rate index, oxygen binding by hemoglobin, and oxygen consumption have been examined in patients with acute myocardial infarction. Proportional extraction of oxygen increased in close association with decreasing oxygen flow rate, and hence, whole body oxygen consumption was constant over nearly a three-fold variation in arterial oxygen flow rate. A reduction in hemoglobin-oxygen affinity at in vivo conditions of pH. Pco(2) and temperature also occurred in proportion to the reduction in arterial oxygen flow rate. Therefore, the increased proportional removal of oxygen from arterial blood at low oxygen flow rates, required to maintain oxygen consumption, may have been facilitated by the reduced affinity of hemoglobin for oxygen at in vivo conditions. However, the decrease in affinity did not appear to explain more than 30-40% of the increased extraction. Respiratory alkalosis was a frequent occurrence in these patients and 2,3-diphosphoglycerate was positively associated with blood pH as well as with the time-averaged proportion of deoxyhemoglobin in arterial and venous blood.Hemoglobin-oxygen affinity measured at standard conditions and the mixed venous oxygen saturation were equally good indicators of reduced arterial oxygen flow rate in patients without shock. However, Svo(2) is more easily measured and is a more useful indicator of reduced oxygen flow rate, since its relationship to oxygen flow appears to be independent of affinity changes and time.
对急性心肌梗死患者的动脉氧流量指数、血红蛋白的氧结合以及氧消耗之间的相互关系进行了研究。随着氧流量降低，氧的比例摄取增加，因此，在动脉氧流量近三倍的变化范围内，全身氧消耗保持恒定。在体内pH值、二氧化碳分压和温度条件下，血红蛋白与氧的亲和力也随动脉氧流量的降低而降低。因此，在低氧流量时为维持氧消耗而增加的从动脉血中按比例摄取的氧量，可能是由于体内条件下血红蛋白与氧的亲和力降低而促成的。然而，亲和力的降低似乎只能解释增加摄取量的30%-40%。呼吸性碱中毒在这些患者中很常见，2,3-二磷酸甘油酸与血液pH值以及动脉血和静脉血中脱氧血红蛋白的时间平均比例呈正相关。在无休克的患者中，在标准条件下测得的血红蛋白与氧的亲和力和混合静脉血氧饱和度，同样都是动脉氧流量降低的良好指标。然而，混合静脉血氧饱和度更容易测量，并且是氧流量降低的更有用指标，因为它与氧流量的关系似乎独立于亲和力变化和时间。
