Open water swimming could pose this type of risk for older women

By Stephen Beech via SWNS

Open-water swimming could trigger potentially fatal fluid on the lungs, warns a new study.

Older women who swim long distances in cold water are particularly vulnerable, say doctors.

And the condition often occurs in people who are otherwise fit and healthy, they warned in the journal BMJ Case Reports after treating a woman.

Fluid on the lungs, also known as pulmonary oedema, is a relatively little-known hazard associated with open-water swimming.

Study author Dr. James Oldman said: "Older age, swimming long distances, cold water, and female sex are among the risk factors, as are high blood pressure and pre-existing heart disease.

"But it frequently occurs in those who are otherwise fit and healthy."

Open-water swimming has become very popular, with more than three million enthusiasts in England alone.

But mounting evidence points to a link between the activity and a condition called swimming-induced pulmonary oedema (SIPE).

First reported in 1989, SIPE leaves swimmers struggling to draw breath and depletes their blood of vital oxygen. It affects an estimated one to two percent of open-water swimmers.

But medics say cases are likely to be underreported.

Dr. Oldman, of Royal United Hospitals Bath NHS Foundation Trust, said: "The woman in question was in her 50s and a keen competitive long-distance swimmer and triathlete.

"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 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 oedema.

"Further scans revealed that fluid had infiltrated the heart muscle, a sign of strain known as myocardial oedema. But she had no structural heart disease."

He said the symptoms of the woman, who has not been named, settled within two hours of arrival at the hospital. And after careful monitoring, she was discharged the following morning.

Dr. Oldman said: "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 he says recurrence is common and has been reported in 13 percent to 22 percent of scuba divers and swimmers, suggesting a predisposition to the condition.

Doctors 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, doctors recommend stopping swimming and getting out of the water straight away, then sitting upright, and calling for medical assistance if required.

Dr. Oldman added: “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."