6533b7d1fe1ef96bd125d5ec

RESEARCH PRODUCT

Une méthode rapide et simple pour l'estimation de la position de la courbe de dissociation de l'oxyhémoglobine

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The methods currently available for assessing the oxyhaemoglobin dissociation curve parameters are expensive, lengthy, require a large volume of blood, and the results obtained are modified by anaesthetic gases. The equipment required for the method described includes: a microtonometre, microcuvettes, 3 gas bottles containing different oxygen, carbon dioxide and nitrogen mixtures (4.5%, 5.6%, 89.9%; 3.5%, 5.6%, 90.9%; 2.5%, 5.6%, 91.9% respectively), a microxymetre, and a micropHmetre. The samples in the microcuvettes are incubated at 37 degrees C in a gas flow of 45 ml.min-1 from the bottles. SO2 is then read using the microxymetre. P50, i.e. PO2 at 50% saturation, is calculated, as well as Hill's number "n" (the angle of the oxyhaemoglobin dissociation curve). The PO2 required for Hill's formula is also calculated from the atmospheric pressure, the water vapour partial pressure, and the oxygen fraction in the gas bottle used. Normal values obtained by this method were P50: 26.5 +/- 1.5 mmHg; Hill's number: 2.65 +/- 0.35. The method presented here, requiring only 300 microliters of blood, is cheap, reliable, not affected by anaesthetic drugs, and quick.