Most people think that the most common diving injury is Decompression sickness, correct??
Well no it’s not, the most common injury and the EASIEST to prevent, is some form of Barotrauma to the ear. Barotrauma means injury from pressure (baro = pressure + trauma = injury). This type of injury occurs for a variety of reasons, but generally it develops when the pressure in the middle ear is not equal to the pressure of the outside environment as a diver descends in the water column. The first 14 feet / 4.2 meters of descent is were the ear is most risk of injury, the difference of 4.5psi to 10psi is enough to rupture the eardrum.
PROBLEMS WITH SINUSES AND EQUILIZATION
TOOLS FOR IMPROVEMENT
* Better understanding of the anatomy of the ear
* Most common injuries
* Typical signs and symptoms
* Suggestions for mechanically improve equalization
* Medication use
* Field management
ANATOMY OF THE EAR
The lobe helps direct sound towards the ear canal then to the eardrum, the lobe and eardrum are known as the external ear. You could say the ear is like a boat which has a mechanical, a hydraulic and a electrical system.
The ear works as sound passes down the ear canal, which in turn causes the ear drum to vibrate which pushes the small bones MALLEUS INCUS & STAPES also known as the HAMMER ANVIL & STIRRUP bones.
As the eardrum vibrate it pushes against the small bones which tap against the cochlea
(snail looking device) this is filled with fluid. The eardrum, external ear and the small bones in the ear are the mechanical system, underneath the stirrup both the round and oval window are located these separate the middle ear from the inner ear. The round and oval windows are two of the thinnest membranes in the human body.
The cochlea round and oval window are part of the inner ear everything else from your drum and the bones are the middle ear, this you could say is the hydraulic system.
The cochlea is filled with fluid and as the stirrup taps on the oval window the round window bulges out the hydraulic system is fluid moving back and fourth due to the vibration. Located at the top of the cochlea are the semi-circular canals these are the tubes which the fluid move through. Lining these canals are little hair like structures known as CELIA as the fluid moves though these canals the Celia pick up the movement and this is what helps use with our balance.
There are injuries that affect the inner ear these are a ROUND or a OVAL WINDOW RUPTURE, and INNER EAR VESTIBULAR DECOMPRESSION SICKNESS, if you suffer one of these you would have trouble walking, keeping your balance you would be very nauseated.
The electrical system is the nervous system attached to the cochlea, this is the auditory nerve which carries the signal to the brain. The brain interprets things as sound the nerves are also connected to the semi-circular canals which help us with balance.
The key structure that is problematic for divers is the Eustachian tube which connect the back of the throat to the middle ear . They keep the middle ear equalized by keeping both sides of the eardrum the same. Because they are surrounded by cartilaginous tissue they don’t allow for expansion. Therefore a diver must equalise their ears by gently opening the tubes and passing air through them into the middle ear.
Frontal sinus; Above the eyes
Maxillary sinus; Behind the cheekbone
Ethmoidal sinus; Sphendoid; Behind the eyes
What is important to know is that with all sinuses there is a phenomenon known as referred pain, this means that the area being affected can actually register pain in other places, for example the Frontal sinus can register pain to the top of the head.
If you had a problem with your Frontal sinus you would have a headache in the forehead but also at the top of the head, the Maxillary sinus can cause pain in the teeth The Ethmoidal sinus can give you stabbing pains in your eyes or the felling of pressure behind the eye. The sphenoid sinus can cause pain in the back of the head at the base of the skull.
The middle ear Eustachian tube and sinuses are lined with mucus membrane which is a soft tissue that lines all these areas this can cause problems. It is important to remember these mucus membranes are very Vascular which means they have a lot of blood vessels (capillaries). These capillaries can easily fracture or break, the eardrum also have capillaries that supply blood, so an injury to the eardrum can cause bleeding in the eardrum or to the outside. The mucus membrane being so vascular can be prone to swelling and becoming inflamed it can act like a one way valve. A thing to keep in mind is that as we equalize during descent this is an ACTIVE process, This means we have to push air through the Eustachian tube which could be blocked with mucus or congestion, The problem is that as were ascending the air we have added at depth has to be able to vent and that is a PASSIVE process, we don’t normally have to do anything for it to happen but the mucus and congestion that we were able to push past during decent now is going to act as a value and block the air trying to vent this is a REVERSE BLOCK. This is why it is important not to dive with a congestion or mucus.
We have to equalize because if the pressure on the outer ear is different than the pressure on the middle ear the pressure difference of 4.5psi to 10psi is enough to rupture the eardrum, (1 foot of freshwater =.433psi 1 foot of seawater=.455psi ).
The most common injury is a MIDDLE EAR BAROTRAUMA
* MIDDLE EAR BAROTRAUMA (MEBT)
Fluid blood drawn from soft tissue
Relative negative pressure
Eustachian tubes collapse and swell
Pain on assent commonly caused by MEBT
Pain or pressure in the sinuses in ether ascent or descent
If we cannot match the pressure it will cause an injury, It will cause fluid and blood to be drawn from the soft tissue in the middle ear and Eustachian tube causing them to collapse and begin to swell this is called a MIDDLE EAR SQUEEZE.
A REVERSE BLOCK is pain on ascent the most common cause is someone who had problem on descent causing a MEBT .
With the sinuses you can have pain on ascent or descent, the sinuses are solid cavities within the bone which have vascular mucous membranes lining them. When you feel a lot of pressure from the sinuses the key is to equalize. You can have a squeeze or barotraumas to the sinus as easily as the middle ear.
The most common injury which occurs and what’s happening in the ears.
At 4ffw the pressure has increased to 1.73psi, The oval and round window bulge inwards and fluid mucus fills the Eustachian tube, capillaries and nerves stretch in the ear drum and membranes. At 8ffw the pressure has increased to 3.46psi, blood and mucus is filling the middle ear the Eustachian tube is forcibly shut and the sinuses are filling with blood with lessoning discomfort.
At 8ffw it’s very difficult if not impossible to equalise at this depth the sinuses are starting to fill up with blood a diver can report that if they stay at depth the sinus pain starts to resolve the reason being the blood has started filling up the sinuses and airspaces
TYPICAL SIGNS AND SYMPTOMS
MIDDLE EAR SYMPTOM - MILD
Fullness (Muffled hearing or water in ear)
Dizziness light headedness or tinnitus
Varying levels of discomfort
Popping and cracking in the ear
SINUS SYMPTOMS - MILD
Pressure in affected sinus
Light headedness or dizziness
MIDDLE EAR SYMPTOMS ACUTE
Sense of hearing lose
Feeling off balance
Blood in sputum
Acute pain (Forehead cheeks teeth)
Numbness in cheek, teeth or gums
COMMON DIFFICULTIES TO EQUALIZE
* Diving with cold or flu
* Otitis externa
* Medical issues
* Chronic allergy symptoms
* Structural anomalies (deviated septum or polyps)
* Improper techniques
* Buoyancy control
* Waiting too long to equalize
* Impacted cerumen (ear wax)
* Wearing a hood
The number 1 problem with equalizing and diving with a cold or flu followed by allergies they cause inflammation and mucous production, this causes the mucous membrane to become swollen and inflamed this not only makes clearing difficult, but it may prevent it altogether.
Otitis externa (swimmers ear) is inflammation of the external ear caused by infection. Some people are prone to developing this kind of infection. If the ear remains moist after immersion in water, the moisture coupled with the warmth from the body, create a area for micro organisms to grow (bacteria). Prevention is the key swimmers ear drops prevent the infection.
A history of childhood ear infections may leave the Eustachian tube scarred and partially occluded. Hayfever can produce swelling of the mucous membranes or cause nasal polyps that can partially or completely occlude a sinus cavity or airway.
A structural anomaly such as a deviated septum (cartilage in the bone that runs up the centre of the nose) which should be straight but when bent it can make it difficult to equalize on one side of the other. Polyps are little growths that show up in mucous membranes and as it doesn’t take much to interfere with air movement in and out of the sinuses or middle ear these can cause a problem.
The problem could be as simple as ear wax (impacted cerumen) forming a plug in the ear, This can then stop the air passing preventing you from equalising. If you suffer from ear wax do not use cotton buds, This can push the wax further into the ear and you can damage the eardrum. Simply flush the ear with warm water using a syringe.
Wearing a hood can make it difficult to equalize because the hood is tight against the ear canal restricting the water column from moving, simply putting a finger into the hood were the ears are and pull the hood away allowing the water column to move.
OVER THE COUNTER MEDICATION USE IS CONTROVERSIAL
* Intended for short term use
* Effectiveness is limited by time
* Primarily treat symptoms not underlying condition
PRESCRIPTION MEDICATION IS LESS PROBLEMATIC
* Can be used long term
* Some take longer to reach optimum effect
*Addresses the underlying condition
* None known to be problematic to diving
Most of the over counter Decongestants are designed to be used as short term, if you read the boxes they tell you no more than 3 to 5 days so keep that in mind if you intend to use them. If you use them often they begin to lose there effectiveness and they also stop working as they should. Most last for 4 to 6 hours therefore the concern is that they wear off while diving, consider one with a 12 hour formula these are less likely to wear off.
Decongestants and vasoconstrictors constrict the blood vessels in the mucous membrane and they also reduce mucus production.
Antihistamines stop histamine production, The body releases histamine when it is experiencing a allergen, they help prevent swelling and inflammation they also prevent mucous production. The main side affect with antihistamines is drowsiness (most over the counter treatment for sea sickness also contain antihistamines) use as directed and do not over use.
Prescribed medications are less problematic and you can use them over a longer period of time, some of them have to be started a week before you dive to make sure they have reached maximum effectiveness.
Some recent research shows that some of the over the counter decongestants that were reputedly a problem were found not to be anywhere near the problem they were believed to be..
Ear injuries are the most commonly encountered injuries to divers, but is one of the easiest to prevent by equalising early and often. Permanent hearing loss may result from barotraumas to the ears. The likelihood of injuries are reduced by preventive measures such as;
* Never diving with a cold or other congestion
* Always equalize properly
* Abstaining from diving if you cannot equalise properly
Several types of ear injuries can occur. All of these should be examined by a qualified practitioner. If in doubt regarding the practitioner’s knowledge of diving medicine encourage them to call DAN MEDICAL DEPARTMENT and ask for a consultant.
Otoscopic examination of the ear by a qualified medical practitioner, Knowledgeable in diving injuries may be useful in determining what type of injury has occurred.
PLEASE NOTE NO ARTICLE CAN GIVE YOU THE SAME DEGREE OF INFORMATION AS A EXPERIENCED MEDICAL PRACTITIONER.
DAN SUGGESTS ALL PERSONS WITH ANY EAR DISCOMFORT SHOULD BE EXAMINED BY A QUALIFIED MEDICAL PRACTITIONER AS SOON AS POSSIBLE AFTER A THE COMLPAINT DEVELOPS.
DAN EMERGENCY HOT LINE