(See also Overview of Diving Injuries.)
Immersion pulmonary edema has become more widely recognized over the past 2 decades. Immersion pulmonary edema is not related to pulmonary barotrauma or decompression sickness. 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 at the surface 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 is often present.
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 have been reported. 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 is not indicated.
1. Peacher DF, Martina SD, Otteni CE, et al: Immersion pulmonary edema and comorbidities: case series and updated review. Med Sci Sports Exerc, 47(6):1128-34, 2015. PMID: 25222821. doi: 10.1249/MSS.0000000000000524
2. Grünig H, Nikolaidis PT, Moon RE, et al: Diagnosis of swimming induced pulmonary edema: a review. Front Physiol, 8:652, 2017. PMID: 28912730; PMCID: PMC5583207. doi: 10.3389/fphys.2017.00652
3. Hårdstedt M, Seiler C, Kristiansson L, et al: Swimming-induced pulmonary edema: diagnostic criteria validated by lung ultrasound. Chest, 158(4):1586-1595, 2020. Epub 2020 Apr 28. PMID: 32360726. doi: 10.1016/j.chest.2020.04.028
Prevention efforts aim to identify people at high risk. Individuals who have experienced immersion pulmonary edema should be screened for predisposing conditions such as hypertension, valvular heart disease, cardiomyopathy, and lung disorders. Silent coronary artery disease should be considered in individuals at risk. Immersion pulmonary edema tends to recur in susceptible individuals, thus before such individuals return to diving or competitive swimming they should be evaluated for treatable risk factors.