Pathologie-biologie
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Pathologie-biologie · Apr 1997
Right shift of the oxyhemoglobin dissociation curve in acute respiratory distress syndrome.
Deep hypoxia is known to increase the intraerythrocytic 2,3 diphosphoglycerate (DPG) level and therefore to induce a right shift of the oxyhemoglobin dissociation curve (ODC), which is considered to be a protective mechanism against tissular hypoxia. Our purpose was to assess whether the ODC is shifted to the right in patients with acute respiratory distress syndrome (ARDS) and whether this shift had a beneficial effect on tissue oxygenation. We have determined the whole ODC and related indices in 29 control subjects and 29 patients suffering from ARDS for at least 5 days. ⋯ A right shift decreases therefore the captation of oxygen from the lung. On the other hand theoretical studies have shown that at low arterial PO2 values a right shift of the ODC has a detrimental effect on release of oxygen from hemoglobin if the mixed venous PO2 is decreased. In order to quantify the amount of oxygen actually transmitted to the tissues, others factors are to be investigate as the PCO2 or the temperature.