Barotrauma: Description, Causes and Risk Factors:
A barotrauma is a pressure related injury. Many kinds of barotraumas are possible in diving, such as lung, sinus, and ear barotraumas. An ear barotrauma occurs when a diver (someone who works underwater) cannot properly equalize the pressure in his ears with the surrounding water pressure. Common causes of an ear barotrauma are ineffective equalization techniques, congestion, exceedingly forceful equalizations, or skipped equalizations. 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
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 also 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.
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.
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). Divers experiencing a middle ear barotrauma on descent report a build up of pressure and eventually pain, accompanied by an inability to equalize. 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.
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.
During an inspection of the ear, the doctor may see a slight outward bulge or inward pull of the eardrum. If the condition is severe, there may be blood behind the eardrum. Severe barotrauma may be difficult to tell apart from an ear infection. 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.
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. 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 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.
• Don't dive when sick or congested. The eustachian tubes may be congested or swollen and will not allow for efficient equalization.
• 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.
NOTE: The above information is educational purpose. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.