ISSUE 20 ARCHIVE - EARS AND DIVING

Dr Mike Gonevski

"Doc, I was wondering if you could give me some advice. I've recently taken up scuba diving and I've just finished my pool sessions and am ready to embark on open water lessons this weekend! However, I've been having lots of problems with my right ear when equalising. Each lesson I've had in the deep end of the pool (4m) I've not been able to equalise on the right side. I can hear squealing and popping and it's quite painful, but as I've only had to endure the pain for a couple of minutes at a time I've just put up with it. Unfortunately, after my last session I was in pain for days with ringing in my ear and a feeling of pressure in there. It has since subsided but I'm concerned about diving this weekend and whether I'll be able to complete the course. Could you possibly advise on the best course of action, as I obviously don't want to cause any permanent damage to my ears."

If this sounds familiar, something that either you or a fellow dive buddy has suffered from, you are not alone, and as we get into the diving season this becomes more common.

Let me ask you a question first. What is the most common diving related injury? You'd think Decompression Illness, right? Wrong.

Ear problems come first, bar none. They far outnumber the cases of decompression Illness or any other diving related injury.

So, what is this fine tuned instrument that on occasion prevents you from getting a taste of the same planet/ different world?

The external ear is the part that we most often refer to as the "ear". It is mainly cartilage, shaped like a funnel and covered with skin. It channels air and in our case water to the Holy Grail of diving – the Eardrum (tympanic membrane). The ear canal is located directly behind the cartilaginous prominence at the front of the ear. It curves forward and is approximately 2 and a half cm. The external ear contains the glands which produce earwax. Too much of it and despite our best efforts the eardrum can remain invisible, even to the most inquisitive eye.

The end of the ear canal, starting with the eardrum (the tympanic membrane) is where the Middle Ear is located. It is an air-filled space that contains three tiny bones that conduct sound; they are most commonly known as the hammer, anvil and stirrup. In medical terms they are known as the malleus, incus and stapes. Regardless of the terminology, what they do is conduct vibration to the inner ear, eventually transferring the signal into nerve impulses which the brain registers as sound. The Eustachian tubes, one in each ear, connects the middle ear to the back of the throat. They are responsible for equalising the middle ear on both sides of the ear drum. They are surrounded by cartilage that prevents expansion. In some people they are naturally very narrow and this makes it very difficult to equalise despite their best efforts.

Separating the middle ear from the inner ear are two very thin membranes, the round and oval windows. They are so thin in fact that a very vigorous equalisation can lead to a perforation and leakage of fluid from the inner

to the middle ear. This can be accompanied by ringing in the ear, in severe cases even hearing loss. Window rapture can also lead to vertigo and vomiting.

Basic diving physiology helps to better understand what you can do to avoid these problems. When you fail to increase the pressure in the middle ears to match the surrounding pressure around you, the result is pain and potential damage to the delicate ear mechanisms. The key to successfully equalising is opening the normally closed Eustachian tubes, allowing higher pressure from your throat to enter the middle ears. Most divers are taught to equalise by pinching their nose and blowing gently. Called the Valsalva manoeuvre, it essentially forces the tubes open with air pressure.

A better way is to use the throat muscles to pull your Eustachian tubes open. You already do this hundreds of times a day while swallowing – just listen for that faint "pop" you hear about every other gulp. The rapid pressure changes of scuba diving however are more challenging. So, which technique to use in order to equalise?

THE VALSALVA MANOEUVRE

is by far the most common one as it is usually the technique taught in dive certification classes. Just close your mouth, pinch your nose and blow gently. The emphasis should be on the word "gently". There are two problems with the Valsalva manoeuvre. First, it may not work if the tubes are already blocked and second, it is too easy to blow hard enough to damage something. And this "something" is either the oval or the round window of the inner ear. Or both.

This can occur if you are overly excited or are having difficulty equalising during descent – especially if you wait too long before attempting to equalise and the only thing that you see are the air bubbles of your dive buddies several metres below you.

THE FRENZEL MANOEUVRE.

Start by closing your mouth and pinching your nose. Then close the back of your throat as if straining to lift weight. This forces the back of your tongue upwards, compressing air against the openings of the Eustachian tubes and this allows air into the middle ear.

THE TOYNBEE MANOEUVRE.

With your nostrils pinched, swallow. Swallowing pulls open the Eustachian tubes while the movement of the tongue, with the nose closed, compresses air against them.

VOLUNTARY TUBAL OPENING.

This is my personal favourite but

it requires a lot of practice. Tense the muscles of the soft palate and the throat while pushing the jaw forward and down as if starting to yawn. These muscles pull the Eustachian tubes open. Mastering this technique allows you to descend with impressive speed and ease.

THE LOWRY TECHNIQUE.

A combination of Valsalva and Toynbee. While closing your nostrils, blow and swallow at the same time.

THE EDMONDS TECHNIQUE.

Another combination technique. While tensing the soft palate and the throat muscles try pushing the jaw down and forward and do a Valsalva manoeuvre at the same time.

Hoping that you still have underwater dreams and not nightmares, here is how you can approach equalisation.

Like most things in life, practice makes perfect.

Start to practice equalising a few days before diving, for example 20 times daily, so the eardrum is flexible and limbered up. People that have difficulty equalising most often have Eustachian tubes that are slightly narrower than most and hence there is less leeway to play with. The Eustachian tube is only approximately 3 mm wide, so it only takes a tiny amount of congestion to block it entirely. The key is therefore to try to widen the passage as much as possible. This is often a question of hoping that the cumulative effect will resolve the problem. Simple things you should try avoid are alcohol, tobacco and dairy products before the dives, as they all increase mucus production. Never try to dive with a cold or sinus blockage.

When you start the dive itself, start equalising early while still on the surface, descend feet first, slowly clearing the ears with each breath.

The first few metres are crucial, as this is where the biggest pressure changes take place.

It is best to start equalising before discomfort occurs, preferably as soon as you start descending. Continue equalising every metre during the descent so the pressure does not have time to build up. Swallow if that works. If you get stuck, ascend, wait and try again – trying to push through it and descending further will only cause more pain and lead to barotrauma. This should generally be sufficient to relieve the symptoms. If you still can't clear, calling the dive off may be the only option because continuing your descent without equalising can lead to barotrauma which is another name for a pressure – related injury.

As the surrounding pressure increases during a descent, air spaces in the sinuses and the middle ears must be able to equalise to the surrounding air pressure, or you'll feel pressure or pain from one of these areas. And it can happen on the way up too. During ascent, if the surrounding air can't escape, the pressure increases leading to discomfort. This type of injury can range in severity from mild, which usually manifests itself as minor discomfort to extreme, which leads to intense pain, possibly causing damage to the inner ear.

Other symptoms of barotrauma involve decreased or muffled hearing, roaring or ringing in the ear (tinnitus), nausea, vomiting, dizziness and a sensation of spinning (vertigo). These types of injuries require urgent medical treatment. Blood coming from the nose at the end of the dive may also indicate barotrauma and doesn't have to be associated with other symptoms.

If you find yourself in any of the above unfortunate situations, you should end the day's diving activities and possibly even for the week. Continuing diving with a barotrauma may result in a serious injury leading to permanent hearing loss, long term or permanent balance control problems, vertigo, infections or perforated eardrums. Difficult equalisation can also be the result of a pre-existing condition, such as a history of ear infections that left the Eustachian tube scarred or partially blocked. A deviated septum whether natural or the result of a broken nose can be responsible for preventing one or both ears from equalizing and simple infections can also cause trouble. The middle ears have the same mucous membranes as those lining the nose and sinuses, and they are subject to any inflammation that occurs in these areas. If part of your middle ear swells as a result of nasal or sinus infections, or from an allergic reaction, you are more than likely to experience problems. Don't dive until these symptoms have resolved. It is not acceptable to dive while taking decongestants to facilitate the dive.

NOTE. This article was not tested on small, furry, cuddly animals. With the exception of a few Canadian seals. But they signed the waivers. No, they could read only French and not English. But whose fault is that?

WARNING. To protect the innocent, the names, dates and places in this article have all remained real. Only the facts have been changed.

CAUTION. Do not disregard the advice in this article under any circumstances. That just might be the difference between taking the plunge or hopelessly observing from the surface. Do not let that be you!

Happy diving.