3. Hypoxemia or hypoxia
Third, the patient may suffer from hypoxemia or hypoxia, which is a decrease in oxygen concentration in the blood due to failure in gas exchange as a result of lung blood perfusion abnormality which is caused by the obstructing thrombus. Hypoxia usually occurs with relatively large thrombi while most of the smaller emboli do not obstruct large vessels and thus do not cause hypoxia.
Low oxygen levels are measured using a special tool called oximeter that is available in ambulance or primary health care facilities. This tool is reliable and gives accurate measures. However, sometimes doctors need a more accurate test called Arterial blood gases test, which is an arterial blood sample withdrawn mostly from your radial artery or less commonly your femoral artery. This procedure is performed in the emergency department to exclude hypoxemia and other medical conditions that may mimic the clinical state of pulmonary embolism, and it is recommended in cases of shock and other severe conditions.
