Postoperative Hypoxemia

Abstract

When venous admixture and oxygen consumption remain constant, a decrease in cardiac output will necessarily decrease arterial oxygenation. To test this as a cause of postoperative hypoxemia, hemodynamic and respiratory gas exchange measurements were made in 14 patients before and after open repair of acquired cardiac valvular disease. Cardiac output was measured by dye-dilution. True shunt (JOURNAL/anet/04.02/00000542-197002000-00011/ENTITY_OV0422/v/2017-07-22T055310Z/r/image-pngS/JOURNAL/anet/04.02/00000542-197002000-00011/ENTITY_OV0422/v/2017-07-22T055310Z/r/image-pngT) breathing 100 per cent O2 and venous admixture (JOURNAL/anet/04.02/00000542-197002000-00011/ENTITY_OV0422/v/2017-07-22T055310Z/r/image-pngVA/JOURNAL/anet/04.02/00000542-197002000-00011/ENTITY_OV0422/v/2017-07-22T055310Z/r/image-pngT) breathing air were measured. A relationship between cardiac index (C.I.) and arterial oxygen saturation (SaO2) was established for groups with JOURNAL/anet/04.02/00000542-197002000-00011/ENTITY_OV0422/v/2017-07-22T055310Z/r/image-pngVA/JOURNAL/anet/04.02/00000542-197002000-00011/ENTITY_OV0422/v/2017-07-22T055310Z/r/image-pngT 0–10 per cent and 10–20 per cent. A decrease in C.I. produced a decrease in arterial oxygenation with JOURNAL/anet/04.02/00000542-197002000-00011/ENTITY_OV0422/v/2017-07-22T055310Z/r/image-pngVA/JOURNAL/anet/04.02/00000542-197002000-00011/ENTITY_OV0422/v/2017-07-22T055310Z/r/image-pngT constant.