What is Air Embolism?

Air embolism is a disease caused by the clogging of cerebrovascular vessels by gas emboli originating in the lungs. It is usually caused by excessive inflation of the lungs when the surrounding pressure decreases (such as when rising from deep to shallow water). Is characterized by pain and / or neurological symptoms. Air embolism refers to the entry of air into the blood circulation to the lungs, obstructing the main pathways of the pulmonary arteries, causing severe shock. This disease is extremely rare and can occur during or after childbirth (including miscarriage) in the field of obstetrics and gynecology.

Basic Information

English name

air embolism

Visiting department

Respiratory Medicine

Multiple groups

Women during or after childbirth

Common causes

Air squeezes into blood vessels through open sinuses

Common symptoms

Irritability, extreme fear, difficulty breathing, cyanosis, etc.

Causes of air embolism

Air embolism can be seen in placenta previa, uterine rupture, stripping of the placenta by hand, inversion, fetal fragmentation, cesarean section, abortion, tubal ventilation, vaginal irrigation, knee-thorax supine position after delivery, etc. While performing the above operations, air can be brought in and accumulated in the uterine cavity. When the operation is performed again, the air in the uterine cavity can be squeezed into the blood vessels through the open sinuses to cause air embolism. If the air enters the right atrium through the vein, it can cause air obstruction between the pulmonary artery and the right ventricle, causing cyanosis and hypoxia; if the intravenous air plug is retrograde to the superior vena cava or through the paraspinal vein plexus, the air can go to Brain, causing convulsions, etc .; if patients with atrial septal or ventricular septal defect, venous air embolism can form arterial air embolism.

Clinical manifestations of air embolism

The typical symptoms are early loss of consciousness, with or without convulsions or other central nervous system symptoms. Sometimes mild symptoms and signs from behavioral changes to hemiplegia can occur. Excessive pulmonary inflation alone or with gas embolism can produce mediastinum and subcutaneous emphysema. Pneumothorax is rare but more severe. Hemoptysis or bloody foamy sputum indicates lung damage. Iatrogenic arterial gas embolism is rare. If consciousness cannot be restored after cardiac surgery, arterial gas embolism should be suspected.

Most patients have sudden onset of illness, sudden irritability, extreme fear, difficulty breathing, cyanosis, severe chest and back pain, depression in the anterior region of the heart, and quickly fall into severe shock. At the medical examination. The patient's pulse is weak or even unreachable; blood pressure drops, or even difficult to measure; dilated pupils and arrhythmia, in the anterior region of the heart you can hear a click from a typical systolic rough grinding wheel-like noise; sometimes in the jugular vein You can feel the bubbles in the blood vessels moving under your fingers.

If the patient is in a high position at the time of onset, it may cause cerebrovascular air embolism. At this point, the patient may develop tonic or paroxysmal convulsions, loss of consciousness, or headache, dizziness, and nausea, followed by dyspnea, weak breathing, cyanosis, blindness, limb paralysis or convulsions, and finally enter shock.

Air embolism diagnosis

Electrocardiogram

Electrocardiogram changes of acute pulmonary heart disease can occur, including signs of pulmonary P waves, right bundle branch block, and right heart strain.

2. Central venous pressure measurement and suction of air

The central venous pressure measured during an air embolism is elevated and air may be aspirated, the latter being diagnostic.

3. Cardiac puncture

When the right ventricle was punctured, the blood drawn from the heart was foamy. It must be pointed out that cardiac puncture must be carried out with caution, and it is generally not suitable to be used, but it can be used in the rescue of cardiac arrest.

Differential diagnosis of air embolism

Amniotic fluid embolism

Occurs most often in obstetric situations, with acute onset. The main clinical manifestations are dyspnea, cyanosis, and shock, which are similar to air embolism. However, patients with amniotic fluid embolism are often accompanied by a significant bleeding tendency, and there is no grinding wheel-like murmur in the anterior region of the heart; air embolism, on the contrary, is not accompanied by bleeding tendency, and grinding-wheel-like murmurs can be heard in the anterior region of the heart, which can be distinguished.

2. Pregnancy-induced hypertension syndrome

Sudden convulsions can easily confuse air embolism caused by air traveling to the brain. However, those with hypertension in pregnancy are often accompanied by hypertension, edema, proteinuria, etc., and those with air embolism have low or even undetectable blood pressure, which is not difficult to identify.

3. Cardiogenic shock

Urgent onset, irritability, cyanosis, chest pain, decreased blood pressure, and weak pulses are similar to air embolism, but with a history of cardiovascular disease, no grinding wheel murmurs in the precardiac area, and ECGs mostly show left ventricular disease rather than acute pulmonary heart disease.

Air embolization

The diver loses consciousness during or shortly after the ascent and must take into account the need for urgent pressurization due to gas embolism. The transfer of patients to the pressurized tank should take precedence over other secondary measures. In order to save enough time, it is best to transport by air, but the low pressure exposure at high altitude must be minimized. In the past, it has been widely advocated that the patient should be supine in the supine position when transporting gas embolism patients, but it has been rarely used.