Pressure leads to panic for diver Diane

Miko Maciaszek

The pressure in Diane’s ear kept increasing despite her efforts to equalize. She did everything she could to relieve the pain: She stopped and hovered; she pinched her nose and blew; she wiggled her jaw and tilted her head from side to side. Nothing helped. The more it hurt, and the more she tried to make it stop, the less she thought about the dive. Right up until she couldn’t think of anything but getting to the surface.

THE DIVER

Diane was 38, with an advanced open water certification. She had been diving for four years and logged 40 dives. Aside from one trip to the ocean, most of her dives were made at a nearby mountain lake 6,000 feet above sea level. She was used to the diving and enjoyed it, although she often talked about getting back to warm Caribbean waters. The lake was clear but cold, and she hated the extra weight and heavy wetsuit she had to wear, not to mention the short diving season. Diane had had a cold the week before the dive, but it seemed to have cleared up.

THE DIVE

Conditions were just about perfect on the mountain where Diane and her buddy, Phil, were diving. The sun was out, and there was very little wind. Water temperatures were in the mid-60s at the surface, although below the first thermocline, it was significantly colder. Underwater visibility was around 20 feet, typical for the dive site. Because of the elevation, Diane and Phil planned the dive using U.S. Navy altitude adjustment tables, diving as if they were at a deeper depth. Their dive computers were also set to account for the altitude. This was their first dive of the summer.

THE ACCIDENT

Diane and Phil walked into the water until it was deep enough to float, donned their fins, and agreed to start the dive. Diane’s problems began almost immediately, but she didn’t realize what was happening until she had been underwater for a few minutes. She was a little rusty from the winter layoff, and it took her a moment to remember her training as she began to descend. Diane equalized for the first time a few feet underwater and attempted to equalize again every so often — mostly when she felt pressure building in her ears. Diane followed Phil down a gentle slope, moving toward some rocks and submerged trees on the bottom. By the time she was 15 feet down, the pain in Diane's ears was distracting. Phil was swimming just ahead of her, and she didn't want to interrupt him. She continued to descend, and tried to fight with the building pain and pressure on her own. At 28 feet, Phil paused to check on Diane. He could tell by the look in her eyes that something was wrong. She wasn't focused on anything other than frantically trying to equalize her ears.

Phil tried to signal to her to calm down, but she didn't acknowledge him. After a moment together, Diane bolted straight for the surface. They were 15 minutes into the dive. Phil surfaced behind Diane, doing his best to ascend safely. When he caught up with her, Diane's regulator was out of her mouth, and her mask was off. She kept saying she couldn’t breathe. Phil helped her to the shore where she lost consciousness; other divers in the area called for emergency medical services. Diane was taken to a hospital and was treated using U.S. Navy Treatment Table 6, but she never regained consciousness.

ANALYSIS

While Diane didn’t have vast experience as a diver, she was relatively experienced in the environment she was in. Diving in mountain lakes comes with its own set of challenges — reduced atmospheric pressure, cold air and cold water — but none of those issues was a factor in this dive accident. Ear problems are by far the most common diving-related injury. Most of the time, they lead to some ear pain, which is caused when blood or plasma leaks into the middle ear as the body attempts to equalize the pressure. Ear injuries, including ear-drum perforations, typically resolve within a few weeks. They many require antibiotics or other care form a physician, but it is rare that they trigger a fatal accident. In most cases, it isn't the problem or trigger that causes an accident, but the diver's response to that trigger. If Diane had stopped her descent as soon as she felt pressure building in her ears, and ascended a few feet to equalize before attempting to go deeper, she would have been fine. But she didn't.

Instead, Diane continued to descend while she attempted to equalize. Just a few feet down, ambient pressure closes the Eustachian tubes that connect the throat to the middle ear, and it is impossible to force air through them — just like a kinked straw. Once the tubes are closed, there is no way to reopen them without relieving the outside pressure. The pain in Diane’s ears led to perceptual narrowing. She began to panic, and the only option she could see was reaching the surface immediately. It’s likely that she forgot to exhale continuously on her ascent, subsequently suffering an air embolism. Diane had had a head cold a few days before the dive, but she felt her symptoms had cleared. It can take up to two weeks before a person's sinus cavities and mucus membranes return to normal, even if the obvious signs and symptoms have cleared. Diane probably had some residual sinus blockages — when her ears didn’t equalize immediately, there was nothing she was going to be able to do about it underwater.

Because of her cold, Diane was unable to relieve her ear pressure, but she used a number of techniques to help with equalization. She moved her jaw from side to side and pointed her “slow” ear upward, which stretches the Eustachian tube and helps it get unkinked. Working against her: Diane and Phil swam down as they descended, following the bottom contour of the lake. Their head-down position made it harder to equalize. Lastly, it had been a while since Diane's last dive, and she could have benefited from a refresher. The amount of time that warrants a refresher course varies for everyone. Some people might be fine with a year between dives; others might need one after six months. This is especially true for those who dive in an area that requires more equipment, heavier wetsuits and more weight to get down. Diane was so focused on her equipment and getting underwater at the beginning of the dive that she failed to equalize, and that set into motion a series of events that led to disaster.

LESSONS FOR LIFE

1. Equalize early and often If you have trouble equalizing, slowly descend feet first.

2. Don't dive congested It often takes up to two weeks for cold symptoms to completely clear, so make sure you're fully recovered before diving.

3. Stay in control Perceptual narrowing and panic lead to bad choices. If you feel yourself struggling on a dive, take time to stop, rest and calm down. If you can't, abort the dive safely.

4. Tune up Take a diving refresher if you have been out of the water for any length of time. A few minutes in a pool or other controlled environment is usually all it takes.