An arterial gas embolism is an incident with potentially catastrophic consequences, which then occurs when air bubbles enter into the arterial vascular system or form there and clog the blood flow, thereby causing Organischämien. An arterial gas embolism can cause central nervous system damage leading to rapid loss of consciousness, other CNS symptoms or cause both; it can also affect other organs. The diagnosis is clinical and can be confirmed by imaging methods. The treatment consists of 100% O2 and immediate recompression.
A gas embolism may enter the arterial circulation on one of the following ways:
An arterial gas embolism is an incident with potentially catastrophic consequences, which then occurs when air bubbles enter into the arterial vascular system or form there and clog the blood flow, thereby causing Organischämien. An arterial gas embolism can cause central nervous system damage leading to rapid loss of consciousness, other CNS symptoms or cause both; it can also affect other organs. The diagnosis is clinical and can be confirmed by imaging methods. The treatment consists of 100% O2 and immediate recompression. A gas embolism may enter the arterial circulation on one of the following ways: through torn alveoli to pulmonary barotrauma through the arterial circulation even in a severe decompression sickness through migration from the venous circulation (venous gas embolism) either a right-left shunt (patent foramen pull ovale, atrial septal defect) or by the overwhelming filtering performance of the lung Even an otherwise asymptomatic venous gas embolism can cause serious findings (z. B. infarction) any right-left shunts by themselves. Venous gas embolism, which does not penetrate into the arterial circulation, is less dangerous. Although cerebral embolism is considered to be the worst manifestation, an arterial gas embolism severe ischemia in other organs (eg. As the spinal cord, heart, skin, kidney, spleen, gastrointestinal tract) can cause. Symptoms and signs The symptoms show up within a few minutes after surfacing, and can an altered state of consciousness, hemiparesis, focal motor or sensory deficits, seizures, loss of consciousness, respiratory failure and shock include; they may have the death. Signs of Lungenbarotraumas or decompression sickness type II may also be present. Other symptoms of an arterial gas embolism may be present in these areas: coronary arteries (. Eg arrhythmias, myocardial infarction, cardiac arrest) skin (eg, cyanotic mottling of the skin, focal paleness of the tongue.) Kidney (eg, hematuria, proteinuria, renal insufficiency. ) Tips and risks Each unconscious diver should be examined for arterial gas embolism and should be immediately subjected to hyperbaric oxygen therapy. Diagnosis Clinical evaluation Sometimes confirmed by imaging methods Diagnosis is primarily clinical. It is alarming in any case, if diver then lose consciousness during the emergence or immediately. It is difficult to confirm the diagnosis because the air in the affected artery before an investigation is often already reabsorbed. Among the imaging methods, which may assist in the diagnosis (each with limited sensitivity) include echocardiography, the air in the heart chambers dargestellen ventilation-perfusion scan: can dargestellen results that are consistent with pulmonary embolism CT of the thorax: Can local lung injury or demonstrate bleeding head CT: can represent intravascular gas and diffuse edema Sometimes decompression sickness is similar (for comparison of characteristics, see table: comparison of gas embolism with decompression sickness). Comparison of gas embolism with decompression sickness property gas embolism decompression sickness symptoms and discomfort Common: loss of consciousness, often with seizures (any unconscious diver should checked for gas embolism and are immediately subjected to hyperbaric oxygen therapy) Less common:. Light cerebral manifestations, evidence of pulmonary barotrauma (eg . mediastinal or subcutaneous emphysema, pneumothorax) Extremely variable – local joint or muscle pain (pain, usually in or near a joint), neurological manifestations almost every kind and every degree, or suffocation (a temnot by circulatory collapse, an extreme emergency) either alone or with other symptoms together start suddenly, usually during ascending or immediately thereafter gradually or suddenly at about 50% symptoms ? 1 h after surfacing; Start up to 24 hours after dives *> 10 m or hyperbaric exposure> 2 (> 33 ft) atm abs immediate cause usual: Stopping air or airway obstruction during the rise (even at only a few meters below the surface, especially if the rise is fast ); Serious decompression sickness usual: dipping or hyperbaric exposure without breaks and without a corresponding decompression occasionally: in the lung retained air expands during ascent and causes a Lungengewebsschaden Occasionally dipping or hyperbaric exposure without breaks or with appropriate decompression stops; Low-pressure exposure (e.g., flying after diving.) Mechanism usual: hyperinflation of the lungs caused by the penetration of free gas in the pulmonary vessels, followed by embolization of cerebral vessels Occasionally: coronary, renal, skin or Kreislaufbobstruktion by free gas from any source the formation of bubbles from excess dissolved gases in blood or tissue when external pressure decreases emergency treatment emergency care as needed (for. example, exposure of the respiratory tract, hemostasis, cardiopulmonary resuscitation or mechanical ventilation) Immediate transport to the nearest decompression chamber Horizontal position 100 % pure O2 anliege by closely hands mask oral fluid intake if the patient is conscious, otherwise i.v. Emergency supply according to demand (z. B. exposing the respiratory tract, hemostasis, cardiopulmonary resuscitation or mechanical ventilation) Immediate transport to the nearest decompression chamber 100% O2 by tight-fitting mask Oral liquid supply when the patient is conscious, otherwise i.v. * Often after repeated dives atm abs = absolute atmosphere therapy immediately 100% O2 Hyperbaric oxygen therapy if it is assumed that a diver has an arterial gas embolism, he should be subjected to immediate hyperbaric oxygen therapy. The transport to a pressure chamber takes precedence over non-essential activities. An air transport may be justified if the time saved is considerable, but the exposure to vacuum in height must be kept as low as possible. Is owned prior to transport 100% O2 administered with high flow, the N2 washout is increased by increasing the N2 pressure gradient between the lungs and circulatory system; This accelerates the reabsorption of Embolusbläschen. Patients should remain supine to minimize the risk of cerebral embolism. Mechanical ventilation, and volume vasopressor therapy are used as needed. It is no longer recommended to keep the patient in the left lateral decubitus position (Durant method) or in the Trendelenburg position. Key points An arterial gas embolism should be considered when patients have neurological symptoms within minutes after surfacing or manifestations of ischemia in another organ. An arterial gas embolism should not be excluded because of negative test results. It should be started immediately with 100% O2 breathing at high flow. Then the transport into a pressure chamber should be done when a gas embolism is suspected. For more information Divers Alert Network: 24-hour emergency hotline, 919-684-9111