Pulmonary edema is a medical condition in which the lungs fill with fluid, making it difficult to breathe. This fluid accumulates in the air spaces and the small blood vessels of the lungs, causing inflammation and reducing the ability of the lungs to exchange oxygen and carbon dioxide. It can be caused by a variety of factors, including heart failure, high altitude, lung injury, and certain medications. Symptoms of pulmonary edema include shortness of breath, chest tightness, coughing up frothy pink fluid, rapid breathing and confusion, fatigue, and bluish skin due to lack of oxygen. Pulmonary edema is a serious condition that requires prompt medical attention, as it can lead to respiratory failure and death.
Otherwise, fit and well, she was struggling to breathe and coughing up blood after taking part in an open water swimming event at night in water temperatures of around 17°C (63°F) while wearing a wetsuit. Her symptoms started after swimming 300 meters.
She had no medical history of note, but experienced breathing difficulties during an open water swim a fortnight earlier which had forced her to abandon the event and left her feeling breathless for some days afterward.
On arrival at the hospital, her heartbeat was rapid, and a chest x-ray revealed pulmonary edema. Further scans revealed that fluid had infiltrated the heart muscle, a sign of strain known as myocardial edema. But she had no structural heart disease.
Her symptoms settled within 2 hours of arrival at the hospital. And after careful monitoring, she was discharged the following morning.
It’s not clear exactly what causes SIPE. But it likely involves increases in arterial pressure in the lungs secondary to centralization of blood volume in a cold environment, combined with an exaggerated constriction of these blood vessels in response to the cold and increased blood flow during physical exertion.
But recurrence is common and has been reported in 13%-22% of scuba divers and swimmers, suggesting a predisposition to the condition, say the authors.
They advise swimming at a slower pace, accompanied, in warmer water, without a tight-fitting wetsuit, and avoidance of non-steroidal anti-inflammatories, such as ibuprofen, to minimize the risk.
For those experiencing symptoms for the first time, the authors recommend stopping swimming and getting out of the water straight away, then sitting upright, and calling for medical assistance if required.
This is just one case, emphasizes the authors, whose aim in reporting it is to raise awareness among doctors and swimmers of a relatively little-known condition.
“The UK Diving Medical Committee has published guidance for divers. However, at present, there are no formal national medical guidelines concerning the recognition and management of this complex condition,” they note.
Reference: “Myocardial oedema in the setting of immersion pulmonary oedema – Cause or effect?” by James Oldman, Sarah Morwood, James Willis and Daniel Xavier Augustine, 9 January 2023, BMJ Case Reports.
DOI: 10.1136/bcr-2022-251274
