Air embolism is a disease caused by the obstruction of cerebral blood vessels by gas emboli originating from the lungs. It is extremely rare and can occur during childbirth or after delivery (including miscarriage) in the field of obstetrics and gynecology. So, what causes air embolism? Causes of air embolism: Trauma (35%): The common causes of air embolism are chest injury and medical injury to the large middle vein. Medical origin factor (30%): In emergency room, air can enter the central vein due to improper operation of chest injury, which can also cause air embolism in the right heart and pulmonary artery, and in serious cases, death is inevitable even if the patient is rescued in time. In addition, in the process of infusion treatment, if too much air is input, it may also lead to air embolism, which is a medical accident. Air embolism pathogenesis: When chest injury causes bronchoalveolar rupture and vascular rupture, so that the trachea communicates with the pulmonary vein, air embolism can occur when the tracheal pressure exceeds the venous pressure, and the gas entering the pulmonary vein passes through the left atrium and left ventricle with the blood flow, and finally flows into the systemic arterial branches, blocking the arterial branches, causing ischemia of the corresponding organs, especially the brain and myocardium, and in serious cases, the blood flow back to the left heart can be obstructed, resulting in severe circulatory failure and the patient’s death. The air embolism in pulmonary circulation or right side of the heart is medical in nature. When doing central venipuncture, if the needle or catheter cavity is not blocked in time, with the increase of negative pressure in the pleural cavity during inspiration, the air can easily enter the central vein; when doing catheterization or placing pacemaker through subclavian vein or internal jugular vein, when pulling out the needle or replacing the catheter, the air can also be sucked into the When the needle is removed or the catheter is replaced, air can also be sucked into the vein, flowing into the right atrium and entering the pulmonary artery through the right ventricle, causing pulmonary artery air embolism, which can lead to pulmonary infarction and severe hypoxia due to extensive spasm of the combined pulmonary artery system, and resuscitation is usually fatal if not timely.