SIPE - Be Aware of the Symptoms

Undercurrent has written about the dangerous in-water condition of swimming-induced pulmonary edema (SIPE) or immersion pulmonary edema (IPE). It was first identified in fit young triathletes who suddenly had difficulty breathing in the swimming section of a competition and was wrongly associated with the effects of cold water.

Since then, more and more otherwise mysterious scuba diving deaths, where the drowned diver still had air in his tank, have been attributed to SIPE. And now, SIPE is considered to be the cause of many unexplained snorkeler deaths in Hawaii. Snorkel-related drownings with no signs of distress have often been a mystery, and we may now know why.

SIPE occurs in all ages of adults and at all fitness levels - even Navy SEAL trainees experience SIPE. However, the frequency increases in middle-aged and older adults who subject themselves to heavy exertion while swimming or diving.

What are the symptoms of SIPE?

It begins when fluid from the arms and legs (which tend to retain water under normal gravity conditions) collects in the lungs of the immersed person rather than returning to the bladder as would be normal. The victim finds it harder and harder to breathe, culminating in asphyxiation. In effect he drowns in his own body fluids.

The only remedy is the total and timely removal of the person from the water.

Preventable?

Though there's currently no standard blood test or chest scan to screen for one's predisposition for SIPE, Richard Moon and his team at Duke University have dedicated hundreds of hours to studying this phenomenon. He has found one way to screen for the condition is a test that requires an oral fluid load exertion and 40 minutes of exercise while immersed in cold water. In this test, most SIPE-susceptible individuals will experience mild symptoms and signs of SIPE.

A fitness check with a cardiologist before engaging in strenuous activities is always advisable, but it does not eliminate the risk of SIPE. So, if you think your regulator is suddenly not performing properly during a dive, get out of the water immediately.