Written by DAN Staff
As the number of divers of retirement age rises, dive safety researchers are increasingly interested in immersion pulmonary edema (IPE). Also called swimming-induced pulmonary edema (SIPE), the condition may occur in young and healthy swimmers and divers, but the risk increases with age and age-related health changes. While IPE can be fatal, divers who are able to recognize the symptoms early and exit the water often have good outcomes, and spontaneous resolution is common.
Here’s what you need to know about IPE:
What is it?
IPE is the accumulation of fluid in the air sacs of the lungs (alveoli) caused by immersion in water. The condition occurs when the pressure in the alveoli is less than that of the fluid pressure in the surrounding capillaries, which causes fluid to seep into the alveoli. Some fluid in the alveoli is normal, but when too much of that fluid is present it can obstruct breathing and cause chest pain, frothy pink sputum and dyspnea (difficulty breathing).
IPE symptoms typically begin to improve immediately after exiting the water, but the condition can cause serious complications, and advanced medical interventions are necessary in some cases.
What are the risk factors?
There are several risk factors that, when combined with immersion, can increase the likelihood of IPE. Exposure to cold water will exacerbate the shunting of fluids to the chest. High blood pressure, overhydration, heart conditions such as left-ventricular hypertrophy, and some genetic predispositions may increase the risk. High-intensity exercise and elevated work to breathe, which may occur with a poorly performing regulator or an inappropriate gas at a deep depth, can also increase the likelihood of IPE by disturbing the fluid balance in the lungs.
Divers can reduce risk by using appropriate thermal protection, avoiding extreme effort in the water, maintaining physical fitness and addressing any potential health-related risk factors before getting in the water.
How should you respond?
If you or your student divers experience symptoms of IPE during a dive, it’s imperative to end the dive as quickly as possible. If symptoms are mild, make a relaxed ascent. However, if symptoms are quickly worsening or are interfering with the ability to breathe, make a direct ascent, get out of the water and seek help.
A diver with symptoms of IPE should breathe 100 percent oxygen and be immediately transported to qualified medical care regardless of whether or not symptoms are improving. It’s possible that the symptoms may have been caused by an underlying cardiac issue that must be addressed by a physician. IPE is likely to reoccur if relevant risk factors are not identified and addressed.
For more information on IPE or safe diving practices, visit DAN.org/Health.