Women warned of open swimming dangers

Middle-aged females at risk of developing a dangerous lung condition in extremely cold water

‘While swimming in a quarry at night I realised I couldn’t swim any further – luckily I was able to call for help’

‘I started to cough and had a metallic taste in my mouth – in the light I could see my sputum was pink and frothy’

MIDDLE-AGED women have been warned by doctors that cold water swimming can lead to a dangerous lung condition.

A healthy regular open water swimmer in her fifties who is a triathlete developed fluid in her lungs which spread to her heart during a night swim in a quarry.

The unnamed patient was rescued and admitted to hospital after hyperventilating and coughing up blood. She has now fully recovered and is back in training.

Doctors say she suffered from a condition called swimming-induced pulmonary oedema (Sipe), which often affects scuba divers.

Experts writing in the journal BMJ Case Reports said swimmers should be told more about the risks of Sipe, which leads to fluid accumulating in the lungs resulting in breathing difficulties and low levels of oxygen in the body.

Among the factors that increase the risks of the condition are being older, female, having high blood pressure and pre-existing heart disease.

It is estimated more than three million Britons go for a swim in open water every year. But doctors warn that cases of Sipe are likely to be under-reported and often occur in those who are otherwise fit and healthy.

The medics, from the Royal United Hospitals Bath NHS Foundation Trust, said the unnamed woman became unwell after taking part in a night swimming event in water temperatures of 17C (63F) while wearing a wetsuit.

Her symptoms started after swimming about 300 yards and were similar to the breathing difficulties she encountered in a race a fortnight beforehand when she said she assumed she was “a bit under the weather”.

“She had coincidentally had her Pfizer Covid-19 booster vaccination six hours before the swim,” the doctors write in the study. There is no suggestion the jab played a role in the incident.

On arrival at hospital she was found to have a racing heart and a chest X-ray revealed pulmonary oedema. Further scans showed fluid had also infiltrated her heart muscle in what is known as a myocardial oedema which caused strain but no structural damage.

The woman’s symptoms settled within two hours and she was discharged the following morning.

What causes Sipe remains “elusive” but is likely to be a combination of increases in blood pressure, an exaggerated constriction of vessels as a natural reaction to the cold and exercise putting increased strain on the organs.

Fluid in the lungs is common in divers, with one in 10 scuba diving casualties presenting signs of pulmonary oedema. Now, doctors believe swimming in cold water may present many of the same risks.

To avoid a recurrence of Sipe, people should not wear a tight-fitting wetsuit, consider swimming at a slower pace, avoid very cold temperatures, and steer clear of anti-inflammatory tablets such as ibuprofen.

“While swimming in a quarry at a night swim I started to hyperventilate and realised I couldn’t swim any further,” the patient wrote in the scientific paper.

“Luckily, I was able to call for help and got guided back to the quay by a paddleboard. When I got out, I undid my wetsuit and immediately felt the sensation of my lungs filling with fluid.

“I started to cough and had a metallic taste in my mouth. When I got into the light, I could see my sputum was pink and frothy.”

“I am now fully recovered and back to full training,” she added.