Swimmer discovers dangers of water blackout

Author: 
by Laura Elder, The Daily News

GALVESTON — When Ball High swim team member Stephanie Scofelia was floating face down in the school’s pool during practice, her teammates thought it was a joke.

Scofelia, 15, was just finishing a 50-meter swim under water the evening of Nov. 12, when her teammates saw her floating near the wall of the pool, her arms and legs hanging limply. “I swam to her and flipped her over,” said teammate and friend Anna Hyatt “That’s when I knew there was a problem.”

Hyatt, 15, and teammate Marissa Streck, 16, pulled a blue and unconscious Scofelia out of the water and called for swim coach Hope Trevino. Trevino, according to the girls, called for Scofelia’s brother Steven, 17, a trained lifeguard and swim team member, who revived his sister using CPR.

“The last thing I remember is almost being to the wall,” Stephanie Scofelia said. “I had no idea why I was laying there.”

What had happened to Scofelia was a little-known but deadly phenomenon known as shallow water blackout. The teenager’s near-death experience underscores the need for more awareness about the problem that is mostly associated with free diving.

Shallow water blackout, according to the Norfolk, Va.-based U.S. Naval Safety Center, which trains Marines and sailors on safety issues, happens when a swimmer such as Scofelia hyperventilates or takes a series of short breaths before going underwater.

Scofelia, ever competitive, wanted to match Streck, who had successfully completed her 50-meter swim underwater. On the evening she blacked out, Scofelia said she hyperventilated in an effort to hold her breath longer under water.

Shallow water blackout, according to the Naval Safety Center, is caused by oxygen starvation. By hyperventilating before going under water, Scofelia had inadvertently manipulated her brain’s automatic breathing-control device. Hyperventilation, according to the center, washes carbon dioxide out of the lungs. Carbon dioxide signals the brain to breathe. Without the signal, Scofelia never got that bursting feeling in the lungs that sends underwater swimmers to the surface gasping for air.

As Scofelia was swimming underwater, she was burning up oxygen through exertion and blacked out from hypoxia, or a lack of oxygen to the brain.

Scofelia was unconscious nearly three minutes say witnesses. The Naval Safety Center says that swimmers in a state of unconsciousness often will fool observers because they don’t appear to be in danger and sometimes appear to be making coordinated movements. Brain damage from a lack of oxygen is only minutes away and often irreversible.

Scofelia’s near-death experience got brief attention when swim coach Trevino, who could not be reached for comment, resigned two days later. After an investigation of the incident, which included interviews with parents and students, the district said there had been adequate supervision at the pool, but paramedics should have been called.

Stephanie and Steven Scofelia went home together after the incident, and she didn’t seek medical treatment. Scofelia’s parents, Greg and Glenda, were shocked by what happened. Stephanie Scofelia has played in swimming pools she was an infant, they said.

“She’s been in the water all her life and she’s never blacked out,” said Glenda Scofelia, 40. “We started looking for answers.”

Few statistics exist on shallow water blackout. But stories on the Internet, along with anecdotes from the Naval Safety Center, show even the most skilled swimmers succumb to it.

In 1988, a chief petty officer, said to be a skilled swimmer, died while alone in a base pool. He was known to practice holding his breath to extend the amount of time he could stay submerged, according to Naval Safety Center.

In 2001, according to the Naval Safety Center, a sophomore at the U.S. Naval Academy fell victim to shallow water blackout while doing breath-controlled laps in a yacht club’s pool. According to reports, the man was trying to go 75 meters underwater when he passed out and went to the pool bottom. Doctors were unable to save him.

The Navy is concerned enough about shallow water blackout that it has directed its commanders to inform personnel about the dangers and to post warnings in swimming areas.

But not enough swim coaches and parents are aware of the dangers of hyperventilating and underwater swimming, said Keith Ozenberger, a training specialist for University of Texas Medical Branch’s education lab. Ozenberger teaches CPR and all advanced American Heart Association classes.

Ozenberger has seen victims of shallow water blackout and said he believes swim coaches and parents should know the risks of hyperventilating and underwater swimming.

“I would caution swimmers not to hyperventilate over two to three breaths and I would definitely caution against any extensive hyperventilation,” Ozenberger said.

What happened to Scofelia is changing some policies. Greg Scofelia has spoken with Maj. Vic Maceo, director of the Galveston County Beach Patrol, who said information about shallow water blackout would be taught in rookie training school.

“Most of our swimmers are competitive and we’re going to go ahead and add that to their training,” Maceo said.

Greg and Glenda Scofelia say they want other families who are going to the beach or spending the day at the pool to also be aware of it.

Stephanie and her teammates have changed the way they practice swimming. The teenagers say they are careful about hyperventilating.

“Because it seemed like I was dreaming and I woke up and there was no pain, I don’t really worry about what could have been,” Stephanie Scofelia said.

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Tips for parents, coaches and swimmers

• Don’t hyperventilate.

• Know that any strenuous exercise while underwater will
drastically limit the time a swimmer can stay submerged.

• Include shallow water blackout as a topic prior to all training for water activities.

• Explain in simple terms to children at a young age what shallow water blackout is and why they should never practice breath-holding diving.

— Source: U.S. Naval Safety Center