Oxygen transport in acute pulmonary oedema and in acute exacerbations of chronic bronchitis.

When breathing air, the average arterial oxygen tension in eight patients with acute pulmonary oedema was significantly higher than in eight other patients suffering from an acute exacerbation of chronic bronchitis, but the mixed venous oxygen tension was very similar in both groups. This largely arose from the smaller arteriovenous difference of oxygen content in the bronchitic cases, presumably due to their higher cardiac output, associated with raised arterial CO(2) tensions. Oxygen therapy (60-90% for pulmonary oedema, 30% for the bronchitics) raised the mixed venous oxygen tensions to a similar level in both groups.

Acid-base balance in acute gastrointestinal bleeding.

Acid-base balance has been studied in 21 patients with acute upper gastrointestinal bleeding. A low plasma bicarbonate concentration was found in nine patients, accompanied in each case by a base deficit of more than 3 mEq/litre, indicating a metabolic acidosis. Three patients had a low blood pH.

Mixed venous oxygen saturation in relation to cardiac output in myocardial infarction.

Mixed venous oxygen saturations derived from measurement of mixed venous oxygen tension were compared with dye dilution cardiac output determinations in 26 patients with acute myocardial infarction. Mixed venous oxygen saturation was greatly reduced in patients with shock or failure complicating myocardial infarction. The level of oxygen saturation correlated with cardiac output determinations.