Courtesy Divers Alert Network
As the number of divers in their retirement years increases, immersion pulmonary edema (IPE) has begun to move into the focus of dive safety researchers. Also called swimming induced pulmonary edema (SIPE), the condition may occur in young and health swimmers, but the risk increases with age and age-related health changes. While IPE may be fatal, divers who are able to recognize symptoms early and exit the water often have good outcomes, and spontaneous improvements are common. Here’s what you need to know about IPE.
What is it?
IPE is the accumulation of fluid in the lung sacks (alveoli) caused by immersion in water. The condition occurs because of a disequilibrium between the fluid pressure in the alveoli and 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 typically presents with chest pain, frothy pink sputum, and dyspnea. IPE symptoms typically begin to improve immediately after removal from the water, but the condition can cause serious complications and advanced medical interventions may be necessary in some cases.
What are the risk factors?
There are several risk factors that, when combined with immersion, can increase your likelihood of experiencing IPE. Exposure to cold water will exacerbate the shunting of fluids to the chest, and high blood pressure, overhydration, heart conditions like left-ventricular hypertrophy, or some genetic predispositions may increase your risk. High-intensity exercise and difficult work of breathing, like you would experience with a poorly performing regulator or an inappropriate gas at great depth, can also increase the likelihood of by disturbing the fluid balance in the lungs. You can minimize your risk by using appropriate thermal protection, avoiding extreme effort in the water, maintaining your physical fitness, and addressing any potential health-related risk factors before you get in the water.
How should you respond?
Should you experience symptoms of IPE during a dive, it is imperative that you end the dive as rapidly as reasonably possible. If symptoms are mild, this does not necessitate a rapid ascent, but if symptoms are quickly worsening or may interrupt your ability to breathe, your safety depends on getting out of the water and reaching help. Once on the surface a diver with symptoms of IPE should breathe 100% oxygen and be immediately transported to qualified medical care regardless whether or not symptoms are improving. Additionally, it is 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.