Immersion Pulmonary Edema

(See also Overview of Diving Injuries Overview of Diving Injuries More than 1000 diving-related injuries occur annually in the United States; > 10% are fatal. Similar injuries can befall workers in tunnels or caissons (watertight retaining structures used... read more .)

Immersion pulmonary edema has become more widely recognized over the past 2 decades. Immersion pulmonary edema is not related to pulmonary barotrauma Pulmonary Barotrauma Barotrauma is tissue injury caused by a pressure-related change in body compartment gas volume. Factors increasing risk of pulmonary barotrauma include certain behaviors (eg, rapid ascent, breath-holding... read more or decompression sickness Decompression Sickness Decompression sickness occurs when rapid pressure reduction (eg, during ascent from a dive, exit from a caisson or hyperbaric chamber, or ascent to altitude) causes gas previously dissolved... read more . Instead, in susceptible individuals it involves development of hemodynamic pulmonary edema due to excessively high pulmonary vascular pressures due to blood redistribution from the periphery into the pulmonary vessels. Risk factors include exposure to cold water, a history of hypertension, lung disorders, and other cardiac disorders that involve abnormal left ventricular systolic or diastolic function (including valvular disorders and cardiomyopathy). This syndrome occurs in divers and, when occurring at the surface, most commonly in competitive open water swimmers.

Severe dyspnea develops, usually while the diver is at depth. Divers usually ascend rapidly and have cough, frothy sputum, scattered crackles throughout both lung fields, and sometimes cyanosis. Hypoxia Oxygen Desaturation Patients without respiratory disorders who are in the intensive care unit (ICU)—and other patients—may develop hypoxia (oxygen saturation < 90%) during a hospital stay. Hypoxia in patients... read more is often present and may result in death.

Chest x-ray shows typical pulmonary edema. Cardiac evaluation usually shows normal right and left ventricular function and normal coronary arteries, but wall motion abnormalities, valvular dysfunction, and cardiomyopathies (including Takotsubo cardiomyopathy) have been reported as causes. Diastolic dysfunction can be documented by echocardiography.

Oxygen administration to treat hypoxemia, and sometimes inhaled beta-2 agonists are usually sufficient to allow immersion pulmonary edema to resolve. Diuretics are rarely required. Mechanical ventilation may be necessary for severe cases. Recompression therapy Recompression Therapy Recompression therapy is administration of 100% oxygen for up to several hours in a sealed chamber pressurized to at least 1.9 (usually 1.9 to 3.0) atmospheres, gradually lowered to atmospheric... read more is not indicated.