What Is a Barotrauma?:
What Causes an Ear Barotrauma?:
At What Depth Is an Ear Barotrauma Likely?:
An ear barotrauma can occur at any depth, but is most common at shallow depths where the pressure change per a foot is the greatest.
If the pressure difference between the middle and outer ear is greater than about 2 psi (pounds per a square inch) a diver's ear drum will be distorted to the point that he is likely to feel pain and discomfort. This pressure difference can occur by descending as little as 4-5 feet without equalizing.
If the pressure difference between the outer and middle ear is 5 psi or greater, an eardrum rupture is likely. This pressure difference can occur by descending as little as 11 feet without equalizing.
Types of Ear Barotraumas:
Outer Ear Barotrauma
• The Outer Ear
The outer ear includes the part of the ear visible outside of the head and the ear canal (the part of the ear that some people clean with a cotton swab). The outer ear is separated from the inner ear by the eardrum (tympanic membrane).
• Causes of an Outer Ear Barotrauma
Normally, a diver's outer ear is open to the water and therefore experiences the same pressure as the surrounding water. Outer ear barotraumas occur when an object traps air in the outer ear, causing either an excess of pressure or a vacuum in the trapped air space as the diver changes depths. Ear plugs, wax blockages, extremely tight fitting hoods, and exostoses (bony growths) can all trap air in the outer ear.
• Symptoms and Signs of an Outer Ear Barotrauma
During an outer ear barotrauma, a vacuum of pressure is created in the outer ear as a diver descends. This vacuum sucks the eardrum outwards and distends the blood vessels and skin of the outer ear. Divers experiencing an outer ear barotrauma have reported pain and difficulty equalizing during descent caused by the distorted eardrum. In extreme cases, the distortion of the eardrum from an outer ear barotrauma can cause a middle ear barotrauma. Signs of an outer ear barotrauma may include small amounts of blood trickling from the ear canal after the dive (from burst blood vessels in the outer ear).
• Treatment and Prevention of an Outer Ear Barotrauma
Unless an outer ear barotrauma has caused a middle ear barotrauma, the burst blood vessels or damaged skin of an outer ear barotrauma will generally heal themselves. To prevent future outer ear barotraumas, a diver should avoid the use of tight fitting hoods and ear plugs, and make sure his outer ears are free of wax and other blockages.
Middle Ear Barotrauma:
The most common kind of ear barotrauma experienced by recreational divers is the middle ear barotrauma.
• The Middle Ear
The middle ear is an air-filled chamber separated from the outer ear by the eardrum and the inner ear by two thin, tissue-covered openings called the round and oval windows. The eustachian tube connects the inner ear with the back of the throat, allowing a diver to equalize the pressure in the middle ear with the surrounding water pressure by adding or venting air through the eustachian tube. A series of three connected bones called the "ossicles" connects the eardrum with the oval window, transferring sound to the inner ear.
• Causes of a Middle Ear Barotrauma
A middle ear barotrauma occurs when a diver cannot equalize the air pressure in his middle ear with the surrounding water pressure. A middle ear barotrauma may occur on descent, when a diver's inability to equalize causes a vacuum in the middle ear, sucking the eardrum and tissues in the middle ear and eustachian tubes inwards. On ascent, the inability to equalize the middle ear air space can cause a build-up of excessive pressure, flexing the eardrum outwards.
Middle ear barotraumas can be caused by eustachian tube blockage due to swelling or congestion (which is one of the reasons it is a bad idea to dive when you are sick). Many divers, especially child divers, may have tight or small eustachian tubes that do not allow the efficient passage of air to the middle ear and can lead to a middle ear barotrauma when proper descent techniques are not followed. New divers are particularly prone to middle ear barotraumas as they are still perfecting their equalization techniques and are likely to equalize either too forcefully or not enough, leading to over or under-pressurization of the the middle ear.
• Signs and Symptoms of a Middle Ear Barotrauma
Divers experiencing a middle ear barotrauma on descent report a build up of pressure and eventually pain, accompanied by an inability to equalize. I have also experienced soreness and pressure in my eustachian tubes as they begin to collapse from the negative pressure.
If a diver continues to descend without equalizing, the vacuum in his middle ear cavity may eventually pull on his eardrum to the point that it bursts. Divers who have thus perforated an eardrum report a build-up of pain and pressure and then a feeling of relief as the ear drum bursts. This sensation is usually followed by a rush of coolness as water flows into the middle ear.
Middle ear barotraumas can lead to inner ear barotraumas (which are much more serious) by exerting pressure on the round and oval windows.
A middle ear barotrauma on ascent feels similar to a middle ear barotrauma on descent although the process is reversed. This type of problem is called a reverse block. Instead of vacuum of pressure sucking the tissues of the middle ear in, the expansion of air in the middle ear on ascent causes over-pressurization of the middle ear, pushing out on the tissues and membranes. The consequences are much the same.
After the Dive:
Mild middle ear barotraumas may be recognized after a dive by the feeling of "fullness" or "water in the ears'' that cannot be relived. This sensation is caused by the accumulation of blood and body fluids in the eardrum and middle ear, not by water in the outer ear. Divers experiencing a persistent feeling of water in their ears after a dive would be well advised to be examined by a doctor, and to not dive until sensation subsides.
Muffled hearing, dizziness, popping or crackling sounds while moving the jaw (caused by air entering accumulated fluid in the middle ear), soreness of the eustachian tubes and ears, squeaking noises during equalization on subsequent dives (caused by inflamed eustachian tubes), and fluid leaking into the throat from the eustachian tubes are all signs of a middle ear barotrauma.
• Classifications of Middle Ear Barotraumas
Diving doctors occasionally use the TEED system to classify middle ear barotraumas.
Type I: Portions of the eardrum are red, possible distortion of the eardrum (in or out)
Type II: Completely red eardrum, possible distortion of the eardrum (in or out)
Type III: Type II, but with blood and fluid in the middle ear
Type IV: Perforated eardrum with any other accompanying symptoms
• Treatment of Middle Ear Barotrauma
A diver experiencing the signs and symptoms of a middle ear barotrauma should go to a diving doctor or ENT specialist immediately for a diagnosis. The severity and treatment of a middle ear barotrauma varies in a case-by case basis.
In very mild cases, many doctors will prescribe a simple decongestant to help clear the eustachian tubes and fluids from the middle ear. Antibiotics may be prescribed if an infection is suspected. Topical drops are inadvisable; they are designed to alleviate outer ear problems only.
Equalization, changes in altitude, and diving should be avoided until the middle ear barotrauma is healed. This can take from a few days to a few weeks for mild barotraumas, and up to a few months for a ruptured eardrum. Divers who have ruptured their ear drum should be examined by a doctor before returning to diving.
Inner Ear Barotrauma:
• The Inner Ear
The inner ear is responsible for both hearing and balance. Separating the inner ear from the middle ear are the round and oval windows. These openings are covered by some of the thinnest, most delicate tissues in the human body.
The oval window is connected directly to the eardrum by a chain of bones called the ossicles. As the eardrum flexes inwards and outwards, the ossicles transfer this motion to the thin oval window tissue which is pulled outwards and inwards in conjunction with the eardrum.
The round window of the inner ear flexes in response to the movement of the oval window. If the oval window flexes into the inner ear, the round window will bulge out to compensate. The Round window is also effected by changes in endolymph (or inner ear) fluid pressure.
• Causes of Inner Ear Barotrauma
Damage to either the round window or the oval window is classified as an inner ear barotrauma.
Improper equalization techniques or the inability to equalize the ears are the most common causes of an inner ear barotrauma. Forceful valsalva maneuvers (blocking the nose and blowing) can cause a round window rupture if executed when the eustachian tubes are congested or blocked. Blowing hard with a blocked eustachian tube increases the pressure of the inner ear fluid (endolymph) which can blow out the round window.
Continuing a descent while unable to equalize can lead to an inner ear barotrauma. As the eardrum flexes inwards, the pressure is transferred directly to the oval window via the ossicles, causing the oval window to flex inward in conjunction with the eardrum. At this point, the ossicles either press through the oval window (perforating it) or the increased pressure in the inner ear from the oval window pressing in causes the round window to bulge out and burst.
• Signs and Symptoms of Inner Ear Barotrauma
Divers with an inner ear barotrauma experience the tearing or perforation of the round or oval window as a distinct event. Most divers report an immediate feeling of vertigo, possibly accompanied by nausea or vomiting. Vertigo and vomiting can be disorienting, even life-threatening, underwater. Hearing loss and tinnitus (buzzing or ringing ears) are also common signs of inner ear barotrauma.
• Treatment of Inner Ear Barotrauma
Inner ear barotraumas are among the most serious ear injuries a diver can experience. They require immediate medical attention both for treatment and diagnosis, and may often be confused with inner ear decompression sickness. While inner ear barotraumas sometimes heal themselves with bed rest, they frequently require surgery and may be a contraindication for diving in the future.
How Can a Diver Avoid an Ear Barotrauma?:
• Learn to equalize properly.
• Never equalize forcefully.
• Equalize once on the surface before descending. This provides a cushion of air in the middle ears, pre-opens the eustachian tubes and gives you a margin of error in case you neglect an equalization in the first few feet.
• If you commonly have ear problems, descend feet first and head up.
• If you commonly have equalization problems, some doctors recommend practicing equalization on land daily. With practice, equalization becomes easier as you train your body to equalize properly.
• If you are prone to equalization problems, confirm that you can equalize your ears on land before departing on the diving trip. If you can't equalize on land, you will not be able to equalize under water.
• Don't use ear plugs, tight hoods, or anything else that can trap air in the outer ear.
• Don't continue to dive with even a mild barotrauma. Further diving will only exacerbate the injury.
• Learn more about equalization techniques and tips.
• Learn more about how pressure effects scuba divers.
Campbell, Ernest, M.D. “Middle Ear Barotrauma”. 2006-2009. http://scuba-doc.com/Midearbt.html
Delphi, Bruce. “Common Ear Injuries While Diving”. http://www.diversalertnetwork.org/medical/articles/article.asp?articleid=45
Edmonds, Carl; Mckenzie, Bart; Pennefather, John; and Thomas, Bob. “Edmond's Diving Medicine.” Chapter 9: ear Barotrauma. http://www.divingmedicine.info/divingmedicine/Welcome_files/Ch%2009%2009.pdf
Kay, Edmond, M.D. “Prevention of Middle Ear Barotrauma”. 1997-2000. http://faculty.washington.edu/ekay/MEbaro.html