By Wesley Hyatt, DAN Communications, and Joel Dovenbarger, Vice President of DAN Medical Services
Q: I have had trouble clearing my ears, and recently had an eardrum (tympanic membrane) rupture. My ENT (ear, nose and throat) doctor found no problems that would lead to clearing trouble. I never had a broken nose, nor suffer from allergies or ear infections. Even though my eardrum has healed completely, he has advised caution in returning to diving.
Is this something that I should consider using an earplug for in the future? If I have another ruptured eardrum, can I dive if I use an earplug? I have heard a lot of pros and cons. What's the main issue with earplug use?
A: Once a ruptured tympanic membrane (TM) has healed, a diver usually can return to diving. Divers with this injury should exercise caution, however, because a small scar is left in the layer of tissue that makes up the TM. Forceful clearing could cause repeated problems with the membrane.
Although your doctor found no ENT problems, it is possible for you to irritate the eustachian tube (which connects the middle ear with the back of the throat and regulates air pressure on both sides of an eardrum) when you're trying to clear your ears and sinuses. You may even have small eustachian tubes, sensitive to rapid pressure changes. Descend slowly, clearing often, and you may avoid future injury.
As for the use of earplugs, opinions differ on their use in scuba diving. In general, they are not recommended. However, some divers use earplugs in special situations. Divers should also know special considerations before trying them. We asked several referral doctors for DAN to address this issue; we also discussed it with a doctor who created vented earplugs that some divers endorse.
Dr. Allen Dekelboum, an ENT and DAN consulting physician in California, reiterated the common view that earplugs create an air pocket in the ear canal, preventing equalization and resulting in differences in the pressure between the water and a diver's ear canal. This situation could lead to serious injury, he said.
"With an intact tympanic membrane, the increasing water pressure against the earplug and the decreasing volume of air between the plug and the tympanic membrane would have a tendency to drive the plug against the TM," Dekelboum said. "The increasing water pressure also could wedge the plug in the ear canal. If this occurs, there is risk of external ear barotrauma."
To address these concerns, some manufacturers promote the vented earplug, which has a small hole for venting between the water and the ear canal. The holes typically have a valve for pressurization without letting water enter the ear canal.
Dr. Robert Scott, creator of Doc's Proplugs, said his vented earplugs are safe for divers to use. It has one chief advantage, he said: "They make pressurization easier."
Most manufacturers of vented plugs emphasize the ease at which their products equalize. Doc's Proplugs website (http://www.proplugs.com) recommends that divers, to maintain proper pressurization, clear their ears frequently while wearing the earplugs. According to the website, those having trouble clearing with the plugs should check if earwax is pushing against the plug vent or blocking the canal. The website also says that if the vent is fouled by debris while a diver descends, it is best to remove the Proplug, and if it is fouled during ascent, there is no problem: the air and water under pressure can escape around the Proplug.
However, Scott acknowledged that these assertions have not been proved scientifically, that no outside medical authority has endorsed the product or tested it under laboratory conditions to prove the veracity of its alleged capabilities. Scott said the claims are backed up through the use of plugs with hundreds of divers. "I guess you'd call it anecdotal, divers saying they've been good," he said, adding that some 10,000-20,000 divers have bought his earplugs. "That would be a conservative guess," he said.
Said Dekelboum: "I know Dr. Robert Scott, who invented Doc's Proplugs, feels that his vented plugs will keep water out of the ear. I believe he feels that the surface tension of the water against the vent prevents water from getting in. He also believes that the plugs make it easier to equalize the ears. The ProEar 2000 (another plug on the market) people also believe this as well. I was unable to demonstrate that characteristic since I do not have difficulty equalizing. There is much anecdotal claim for both, but I have not seen any data for either."
Longtime DAN consulting physician Dr. Cameron Gillespie said divers could wear vented earplugs, yet he has significant reservations. "I believe earplugs can be used in diving, if vented, but I see little value in using them," he said. "Perhaps earplugs could arguably keep warmer water in the ear canal for comfort and, by reducing thermal conductivity, reduce chill to the canal walls, drum and semicircular canals." Dr. Scott echoed this belief.
However, Gillespie noted, "A wetsuit hood vented over the ear canals would accomplish the same things, and more (such as a significant conservation of the core body temperature), while not reducing surface hearing more than about 5 decibels (dBs) by eliminating the gain normally provided by the external ear."
Gillespie added that "earplugs make surface communication more difficult, because the small vents tend to retain water in the canals, causing up to a 35-dB conductive hearing loss. This could adversely affect safety."
Dr. Ernest Campbell, webmaster of Diving Medicine Online, said he had had several divers write to him, saying the Proplug allows them to dive comfortably after years of difficulty with equalizing and many episodes of middle ear barotrauma.
"I have no personal experience, and the only reason that I can see that they would be beneficial is that they might slow the rate of pressure change on the external surface of the eardrum," Campbell said. "It certainly has no ability to alter the pressure inside the middle ear or the eustachian apparatus."
Campbell said that one diver claimed that he was even able to dive with a perforated eardrum, an activity that is not recommended, since the possibility of middle ear infection is great. "The usual vertigo from water in the middle ear is not as severe - apparently due to the warming effect of the external ear canal on water between the plug and the eardrum," he said.
Dr. Shannon Hunter, an ENT physician at Duke University Medical Center, N.C., also expressed reservations. "I have reviewed the limited information on the vented plugs, and it appears that there is too much of a chance for failure - Too many 'ifs'," Hunter said. "If the plug vent is occluded by wax or debris, it should be removed - at depth? In cold water, where the temperature in the ear canal is warmed by the presence of a plug?
"An influx of cold water to the vestibular system is a setup for vertigo, nausea and even vomiting - this is duplicated every day in vestibular testing procedures used to test patients for balance disturbances. Cold water stimulation of the inner ear (cold calorics) through the ear canal is also reproducible in normal, healthy people and often renders them unable to stand or balance for a period of minutes. Nausea and vomiting are also common side effects of this testing. A similar situation at depth is possible if a fouled earplug were removed and allowed for an abrupt influx of cold water into a warm ear canal. The resultant effects of nausea, vomiting and vertigo could be deadly.
"I concur with Dr. Dekelboum in that there is just not enough data or evidence to recommend the use of plugs for divers. The risks of complications underwater from malfunction or removal of an earplug are real and can potentially place the diver at increased risk for injury."
From the January 2001 issue of Alert Diver.