Secondary Drowning: A Few Drops Can Be Fatal

Last spring, British diver Nigel Braybrooke swam through the breakwater at a Devon beach for his first dive of the season. He prefers to surface-swim with his regulator, but his lack of conditioning soon showed, and he became exhausted swimming against the tide. Because the surface was calm, Braybrooke took his regulator out to gulp more air. Suddenly a small wave broke over his head, causing him to cough and splutter, but he reached his mark and made his dives with no trouble. He had a slight cough the next day, flu-like symptoms on the second, then shortness of breath, hot and cold flashes, shivering and heavy coughing on the third.

Braybrooke was presenting all the signs of “secondary drowning.” It’s not a recognized diagnosis, but a slang term for development of pulmonary edema, the accumulation of water on the lungs. It’s usually associated with someone who suffered “near drowning,” having inhaled water into the lungs prior to death. But dive accident reports show that inhaling a fine mist from faulty regulators can cause the same thing. Braybrooke’s doctor told him he was drowning in his own fluid.

Secondary drowning happens when water enters the airway and causes the spasm of the glottis. Only a small amount of water needs to be inhaled to cause problems. When Braybrooke was taking huge gulps of air, small amounts of water were delivered deep into the lungs. A chemical reaction takes place, drawing fluid from the bloodstream into the alveoli, increasing fluid levels within the lungs and causing respiratory distress. Because it can take up to 72 hours for symptoms to become fully apparent, secondary drowning is often mistaken for a chest infection or pneumonia. Braybrooke got diuretics to flush out the fluid, steroids for inflammation and antibiotics. He was fully fit in 10 days.

Diving circumstances that can cause secondary drowning involve faulty demand valves that let in a fine mist of water; side-mounted demand valves which let water in if tilted at an angle; and buddy breathing. Richard Moon, MD, medical director for Divers Alert Network, says divers who’ve inhaled significant amounts of water should get medical attention even if they feel okay. And if you’re going to be facing heavy-duty surface swims, make sure you’re fit for the task and keep your regulator or snorkel in your mouth while doing so.

Parts of this story were excerpted from “Take Your Breath Away,” written by Nigel Braybrooke and published in DIVE magazine.