摘要：The purpose of the study was to evaluate the behavior of the venous-to-arterial CO
2 tension difference (ΔPCO
2) over the arterial-to-venous oxygen content difference (ΔO
2) ratio (ΔPCO
2/ΔO
2) and the difference between venous-to-arterial CO
2 content calculated with the Douglas’ equation (ΔCCO
2D) over ΔO
2 ratio (ΔCCO
2D/ΔO
2) and their abilities to reflect the occurrence of anaerobic metabolism in two experimental models of tissue hypoxia: ischemic hypoxia (IH) and hypoxic hypoxia (HH). We also aimed to assess the influence of metabolic acidosis and Haldane effects on the PCO
2/CO
2 content relationship. In a vascularly isolated, innervated dog hindlimb perfused with a pump-membrane oxygenator system, the oxygen delivery (DO
2) was lowered in a stepwise manner to decrease it beyond critical DO
2 (DO
2crit) by lowering either arterial PO
2 (HH-model) or flow (IH-model). Twelve anesthetized and mechanically ventilated dogs were studied, 6 in each model. Limb DO
2, oxygen consumption (
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