Increased Extravascular Lung Water in Asymptomatic Open-water Swimmers

Swimming-induced pulmonary edema (SIPE) can occur during open-water swimming. The pathophysiological mechanisms are still partly unknown, but central pooling of blood volume and peripheral vasoconstriction have been suggested as important factors. SIPE is characterized by acute onset of dyspnea and cough, sometimes with excessive sputum and hemoptysis. The condition usually resolves spontaneously, but medical attention can be required in more severe cases. Previous studies suggest that SIPE is diagnosed by clinical symptoms, decreased peripheral oxygen saturation and signs of pulmonary edema on lung ultrasound. Interestingly, signs of increased extravascular lung water have been found in divers without respiratory symptoms. There are no similar studies regarding open-water swimmers. This study aims to investigate a large number of swimmers without respiratory symptoms after finishing an open-water swimming race. Prevalence and amount of increased extravascular lung water after swimming will be assessed by lung ultrasound. In addition, individual baseline factors and information about the race associated with increased extravascular lung water will be evaluated. This study will provide better understanding of the pathophysiological mechanism of SIPE.