Divers beware: 'Bends' can put a crimp in your fun

By ERIK SLAVIN | STARS AND STRIPES Published: April 22, 2005

With each passing week, Okinawa’s warming waters beckon scuba divers eager to glimpse colorful coral reefs and sea life.

Most divers are trained and certified, but some still end up suffering from what commonly is known as “the bends.”

Kadena’s 18th Wing Physiological Flight personnel — who use hyperbaric chambers and other tools to treat divers for decompression sickness and flyers for altitude sickness — treated four people last week.

“As the diving season opens up, I think we’ll start seeing more,” said Lt. Dorian Williams, a physiologist with the Flight’s hyperbaric dive team.

The Flight averages about one patient every three weeks throughout the year, said flight commander and team physiologist Lt. Col. Paul Gardetto.

The cause of injury or discomfort after diving isn’t always clear, Gardetto said.

For example, a Marine came in last week after suffering foot pain for a day. The Flight doctor and physiologist suspected he may have stepped on something but couldn’t be sure.

After the Marine breathed a concentrated, pressurized oxygen in the hyperbaric chamber, his pain — and his limp — vanished.

“We always err on the conservative side,” Gardetto said, because “we can’t see the bubble.”

“The bends” occur when a diver breathing pressurized air retains too much nitrogen. Nitrogen normally is expelled through breathing, but water pressure combined with a rapid ascent causes liquid nitrogen to form gas bubbles in the body.

Early divers who first experienced the condition complained that they could not bend their joints; hence the name “the bends.”

The bubbles produce an ache that may start as soon as the diver surfaces or may begin up to 24 hours later, Gardetto said.

While the bends may go away on their own, a central nervous system disorder or arterial bubble can be dangerous and needs prompt treatment. Symptoms may be as simple as headaches or numbness in the legs, or as serious as paralysis.

“They blow it off it first, then after they haven’t slept for two days, they go and see a doctor,” Gardetto said. “By that time, we’re treating whatever tissue damage … resulted from the bubble.”

Risk factors for decompression sickness include dehydration, age and weight. The body’s vascular system changes around age 30, making divers more susceptible, Gardetto said. Fatty tissue also retains more nitrogen, making the bends more likely, he said.

Multiple dives during the same day, especially if the second dive is deeper than the first, also can put a diver at risk, said crew chief Staff Sgt. Becky Hale.

Paying attention to depth is key to avoiding decompression problems, Gardetto said.

For example, a few months ago a diver dropped a camera at a 30-feet depth. She swam back down to a depth of 80 feet to get her camera, without stopping at intervals to acclimate to the added pressure. When she arrived at the hyperbaric chamber, she was as white as a ghost, Gardetto said.

Divers interested in learning more decompression precautions can arrange a free safety briefing the dive team offers by calling Hale at DSN 634-1967.

Staff Sgt. Michael Mazza "drives" the hyperbaric chamber at the 18th Wing Physiological Flight during a readiness exercise Wednesday. Mazza and the hyperbaric dive team crew treated four divers and flyers for decompression-related sickness last week.

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