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The Effect Of Short-term Oxygen Supplementation On Oxygen Hemoglobin Affinity In Patients With Chronic Obstructive Pulmonary Disease.
Published 1985 · Medicine
In 12 hypoxemic patients with chronic obstructive pulmonary disease, the partial pressure of oxygen at which hemoglobin is 50% saturated (P50) and levels of 2,3-diphosphoglycerate (2,3-DPG) were determined under 3 study conditions: (1) while breathing room air, (2) during oxygen supplementation for 72 h sufficient to increase PaO2 above 70 mmHg, and (3) at 72 h after the period of oxygen supplementation. The data showed that in the control period in hypoxemic (PaO2, 52 +/- 6 mmHg), mildly hypercapnic (PaCO2, 47 +/- 6 mmHg) patients with a borderline elevation of pH (7.42 +/- 0.03), there was an increase in P50 (28.6 +/- 1.6 versus a normal value of 26.5 +/- 1; p less than 0.005), and a concomitant increase in 2,3-DPG (19.02 +/- 1.77 mg/g Hb versus a normal value of 13.52 +/- 1.27; p less than 0.005). Nine patients received oxygen for 24 h, and 5 received oxygen for 72 h. In these 5 patients, oxygen supplementation resulted in a shift in P50 to a normal value of 26.7 +/- 1.8 (this value was different from the patients' level while breathing room air and not different from that of the normoxemic control subjects) and a decrease in 2,3-DPG toward but not to a normal value (16.34 +/- 1.92; p less than 0.01). This shift in P50 to the left could be related to the decrease in 2,3-DPG. Accordingly, in patients with COPD who are treated with supplemental oxygen, the net effect on oxygen transport would be a function of the changes produced in PaO2 versus those in hemoglobin-oxygen affinity.(ABSTRACT TRUNCATED AT 250 WORDS)