New parameters for evaluation of oxygen transport on the dissociation curve of human blood.

Three new parameters were applied to evaluate oxygen transport using the dissociation curve of human blood. They are derived from the following equation: [formula: see text] The first parameter, beta 1,0, reflects the oxygen capacity of the curve within the range of 1.0 kPa at its "arterial section". The second parameter, beta 2,3, reflects the oxygen transport from the "arterial" point to the point of extraction of 2.3 mmol/l-1 of oxygen which is assumed as normal. The third parameter, beta 5-4 kPa, characterises the oxygen transport at the "venous" section of the curve. The parameters were studied on a cohort of 12 healthy people and 141 patients with chronic obstructive pulmonary disease at different stages of respiratory failure. A significant correlation was found between the oxygen capacity parameters, beta 1,0 and beta 2,3, and pO2(a), sO2 and the calculated transpulmonary shunt. They were not influenced by ctHb and ctO2(a). beta 5-4 showed marked correlation with the hemoglobin and total O2 concentration and the parameters that indicate a risk of tissue hypoxia-px and Qx. Standardisation of the new parameters with ctO2(a) correlates it functionally with the parameters of oxygen affinity.