Partial Pressures of Oxygen and Carbon Dioxide, and pH of Blood Sampled from Wedged Pulmonary Artery

1. Po₂, Pco₂ and pH were examined in twenty-seven pulmonary ‘wedge’ samples of blood obtained from seventeen patients with various heart diseases.

2. High Po₂ and pH, and low Pco₂, values were found in comparison with those in simultaneous samples of peripheral arterial blood. In the pulmonary ‘wedge’ samples of blood, the following mean values were found: Po₂, 17.65 kPa (132.2 mmHg); Pco₂, 3.10 kPa (23.2 mmHg); pH 7.47. An explanation of these findings is considered.