by Erik McLaughlin, M.D., M.P.H.

1. As a person realizes he might be drowning, there’s often a large amount of panic. This leads to rapid movements and expending a lot of energy, which consumes more oxygen.
2. At the same time, if the person remains underwater, her body begins to accumulate carbon dioxide. This gas is what stimulates you to feel that need to breathe. Eventually, the victim involuntarily draws in breath.
3. When water reaches the airway, the first response is to cough or swallow the water. This typically results in more water being ingested.
4. As water contacts the lower airways, the throat spasms, trying to seal off the path to the lungs. With nowhere else to go, water frequently finds its way into the stomach.
5. The throat relaxes after the person becomes unconscious. The relaxation allows water to flow into the lungs.

This complex reaction can cause a variety of other problems as well. That’s one of many reasons most experts are beginning to use the term “water-immersion injury” to describe these problems, rather than “drowning” and “near drowning.”

ERIK MCLAUGHLIN, M.D., M.P.H., is a family-doctor resident in Chicago and former EMT/firefighter. He runs the travel health Web site www.AdventureHealthClinic.com.

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Re: Mammalian Diving reflex/near drowning
written by Leigh Ann , February 28, 2011

That is fascinating, Senior Chief Benafel. Thank you for sharing your story.

Leigh Ann Otte
Managing Editor, MyFamilyDoctorMag.com

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Mammalian Diving reflex/near drowning
written by Senior Chief Eric Benafel , February 25, 2011

I have worked for the United States Coast Guard for over 32 years.
One case that is remarkable and stays with me:
A near drowning case that the child recovered... after being under water for more than an hour. Fresh water near drowning, South Umpqua River, Days Creek Oregon. Nine year old child.

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