What is the normal O2 saturation in the pulmonary artery (PA)?

The normal oxygen saturation in the pulmonary artery typically ranges from 70-80%. This value reflects the levels of oxygen in the blood returning from the body before it is oxygenated in the lungs. The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs, and this blood generally exhibits lower oxygen saturation compared to the oxygen-rich blood found in the aorta after it has passed through the lungs.

In a healthy individual, oxygen saturation levels in the pulmonary artery will generally fall within the 70-80% range due to the mixture of deoxygenated blood returning from the systemic circulation. Understanding this range is crucial for clinical assessment and monitoring of patients, as deviations from this normal range can indicate various medical conditions affecting oxygen transport and pulmonary function.