Swimrun athlete hospitalized with swimming-induced pulmonary edema

Swimming-induced pulmonary edema (SIPE) is an uncommon condition that can occur during or shortly after open-water swimming. This case report describes a previously healthy, 23-year-old elite-level swimmer who developed breathlessness and cough about 10 hours into a swimrun race in Stockholm. He continued for a further five hours before being assessed at a checkpoint, where his oxygen saturation was 65% on room air. He had crackles on auscultation and produced pink sputum.

The athlete received intravenous furosemide and continuous positive airway pressure during helicopter transfer. At hospital, lung ultrasound showed numerous B-lines across all lung zones. He was admitted for close monitoring and treated with bilevel positive airway pressure, followed by high-flow oxygen and then standard oxygen. His oxygenation and symptoms improved; he no longer needed oxygen that evening and was discharged to his hotel about 24 hours after emergency-department arrival. Echocardiography showed normal ventricular dimensions and preserved left-ventricular function.

The report highlights that SIPE can affect otherwise healthy athletes and may require urgent respiratory support. The authors cite a diagnostic algorithm using oxygen saturation and lung auscultation, with lung ultrasound as a further assessment. The case illustrates one presentation and course; it does not establish risk factors or treatment effectiveness. The article notes that knowledge of SIPE risk factors remains limited and is based mainly on observational studies.