Air embolism

Introduction to air embolism Air embolism is a disease caused by a gas embolus originating from the lungs that blocks the cerebral blood vessels. It is usually caused by excessive inflation of the lungs caused by the expansion of the lungs when the surrounding pressure is reduced (such as when rising from deep water diving). For pain and / or nervous system symptoms. Air embolism refers to air entering the blood circulation to the lungs, blocking the main pathway of the pulmonary artery, causing severe shock. The disease is extremely rare and can be produced during childbirth or during childbirth (including abortion). basic knowledge The proportion of sickness: 0.03%--0.07% (the incidence rate of deep sea divers is about 0.03%--0.07%) Susceptible people: no specific population Mode of infection: non-infectious Complications: cough, coma

Cause of air embolism

Trauma (35%):

Common causes of air embolism are chest injury and iatrogenic injury caused by large and medium veins. Chest damage causes the gas in the bronchopulmonary to enter the pulmonary vein, causing left heart and systemic air embolism.

Iatrogenic factors (30%):

In the emergency room, when patients with chest injury are injured, air can enter the central vein due to improper operation, and air embolism of the right heart and pulmonary artery can also be caused. In severe cases, even if it is rescued in time, it is inevitable to die. In addition, if you input too much air during infusion therapy, it may cause air embolism, which is a medical accident.

Pathogenesis

When the chest injury causes bronchoalveolar rupture and rupture of the blood vessels, the trachea communicates with the pulmonary veins. When the tracheal pressure exceeds the venous pressure, air embolism can occur, and the gas entering the pulmonary veins flows through the left atrium and the left ventricle with the blood, and finally flows into the branches of the whole artery. Blocking the branches of the artery, causing ischemia of the corresponding organs, especially the brain and myocardium. In severe cases, it can block the blood flow to the left heart, causing severe circulatory failure. The patient can be killed immediately. The pulmonary circulation or the air embolism of the right heart is Iatrogenic, in the case of central venipuncture, such as the needle or catheter lumen failed to block in time, with the increase of negative pressure in the pleural cavity during inhalation, the atmosphere is easy to enter the central vein; through the subclavian vein or internal jugular vein puncture Do a catheterization or place a pacemaker. When the needle is removed or the catheter is replaced, air can also be drawn into the vein, into the right atrium, into the pulmonary artery through the right ventricle, causing pulmonary embolism, which can lead to pulmonary infarction due to the pulmonary system. Extensive paralysis, severe hypoxia, and rescue if not timely, usually fatal.

Air embolism prevention

1. Before infusion, be sure to check whether the connection parts of the infusion set are tightly connected and not easy to slip off. The air must be introduced during the infusion, and the infusion should be replaced in time. Intensive infusion and blood transfusion should not be taken out of the patient.

2, chest injury or hepatobiliary surgery when connecting the drainage tube, must seal the wound to avoid gas into the artery.

Air embolism complications Complications, cough, coma

When the chest injury causes bronchoalveolar rupture and rupture of the blood vessels, the trachea communicates with the pulmonary veins. When the tracheal pressure exceeds the venous pressure, air embolism can occur. The gas entering the pulmonary veins flows through the left atrium and the left ventricle with the blood, and finally flows into the branches of the whole body artery, blocking the branches of the artery, causing ischemia of the corresponding organs, especially the brain and the myocardium. In severe cases, the blood flow to the left heart can be hindered, causing serious The circulatory failure, the patient can be immediately killed. Chest discomfort, difficulty breathing, coughing, irritability, coma, sudden cardiac arrest, and even sudden death can occur.

Air embolism symptoms common symptoms air embolism irritability dyspnea coma circulatory failure wound

Typical symptoms are early loss of consciousness, with or without convulsions or other central nervous system symptoms. Mild signs and symptoms can sometimes occur from behavioral changes to hemiparesis. Excessive lung expansion, either alone or with a gas embolism, can produce mediastinal and subcutaneous emphysema. Pneumothorax is rare but more serious. Hemoptysis or bloody foam sputum suggests lung damage. Iatrogenic arterial gas embolism is rare. If cardiac sensation cannot be restored after surgery, arterial gas embolism should be suspected.

Most patients have a sudden onset of illness, sudden irritability, extreme fear, difficulty breathing, cyanosis, severe chest and back pain, depression in the anterior region, and rapid collapse into severe shock. During the medical examination. The patient's pulse is weak or even inaccessible; blood pressure drops, even difficult to measure; pupil dilated, arrhythmia, in the anterior region can be heard from drip sound to typical systolic rough grinding wheel-like murmur, sometimes in the jugular vein On the upper side, the intravascular blood bubbles can be felt to move under the fingers.

If the patient is at the head high position at the time of onset, it may cause air cerebrovascular embolism. At this point, the patient may have tonic or paroxysmal convulsions, loss of consciousness, or headache, dizziness, nausea, and then difficulty breathing, weak breathing, generalized convulsions, blindness, limb paralysis or convulsions, and finally into shock.

Air embolism check

1. Electrocardiogram: ECG changes in acute pulmonary heart disease, including signs of pulmonary P wave, right bundle branch block, right heart strain.

2. Measurement of central venous pressure and aspiration of air: The central venous pressure is increased when the air is plugged, and air may be drawn. The latter has a diagnostic significance.

3. Cardiac puncture: When the right ventricular cavity is puncture, the blood drawn by the heart is foamy. It must be pointed out that cardiac puncture must be carried out with care and should not be used under normal circumstances, but it can be used in the rescue of cardiac arrest.

4. Doppler auscultation of venous air embolism typically manifests as a mill-wheel murmur, but may be less sensitive.

Air embolization diagnosis

Usually, systemic air embolism is easy to occur after a chest penetrating injury, but it can also occur after blunt chest injury. It is generally difficult to make an accurate diagnosis in time. However, in patients with chest injury, systemicity should be suspected in any of the following cases. Air embolism:

1 no head trauma, but focal neurological abnormalities.

2 ophthalmoscopy revealed bubbles in the retinal blood vessels.

3 Circulatory failure occurs shortly after the start of positive pressure ventilation.

4 When collecting arterial blood samples for blood gas analysis, it was found that the blood contained air or foam, and it was not technically wrong to check (this level of air embolism is extremely difficult to save).

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