Definition.
occlusion of one or more small blood vessels, especially the muscles, tendons and joints, caused by expanding gas bubbles. Gaseous emboli can break the tissues and blood vessels, producing a condition of decompression and death. The phenomenon is experienced by deep sea divers who come too quickly to the surface without adequate decompression and as a complication of surgical procedures, diagnostic and therapeutic.
Symptoms and Diagnosis
characteristic is the early loss of consciousness, with or without seizures or other manifestations. Sometimes they develop signs and symptoms ranging from mild behavioral changes to hemiparesis.
lung hyperinflation, alone or together with air embolism, subcutaneous emphysema may occur or mediastinum. The pneumothorax is less common but more serious. Hemoptysis or bloody sputum suggests a lung injury.
Rarely can cause iatrogenic arterial gas embolism. Should be suspected when a patient does not regain consciousness after an operation for heart surgery.
frequency.
Contrary to what one might think, air embolism that occurs in diving, is much less common than not related to diving. In the United States Navy, presents an average of 2 serious cases per year for a total of 70000 dives in the same period, while according Stonley and al., in approximately 100,000 patients who underwent cardiac surgery, 100 had symptoms of severe AE, of whom 35% died or remained with permanent neurological sequelae.
Pathophysiology.
A Once the gas bursts into the arterial circulation, the bubble will block the traffic, resulting in tissue ischemia, hypoxia accompanied by edema (cytotoxic), which will compromise the microcirculation more so, the gas interface will activate platelets, which will trigger disseminated intravascular coagulation, in turn, will produce an endothelial edema, which will further decrease even the capillary lumen, thereby compromising the picture further. Consequently, the result is acute tissue ischemia.
Treatment.
All divers and dive centers should be aware of centers involving hyperbaric chamber near the place where they operate and how to contact in an emergency.
In the acute stage, the patient should be given oxygen by mask, placed in supine position, administer EV solutions to increase the surface tension of the bubble, making it more unstable, manage Acetyl Salicylic Acid to reduce EV prevent platelet activation and coagulation disseminated intravascular and administer steroids, and now there have been very successful with the administration of lidocaine.
Undoubtedly, the recompression in a hyperbaric chamber and hyperbaric oxygen breathing, is the treatment of choice.
Al recompress the patient, quickly reduces the size of the bubble, according to the law of Boye and Marriott, and consequently reduces the size of the embolus. Hyperbaric oxygen to make breathing creates a positive gradient around the bubble, which causes it to shrink by diffusion of the gas contained within it, out, in turn, is achieved high partial pressure of oxygen, which will fight tissue hypoxia and edema hitotóxico decrease as a result of hypoxia, which further improves microcirculation.
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