Barotrauma (Decompression Sickness)
Barotrauma refers to any medical problems that arise from the pressure differences between areas of the body and the environment. This can occur as a result of flying, as you ascend the air pressure decreases or as a result of diving, where the opposite happens, as you descend the pressure increases.All involve air being trapped in an enclosed area where the pressure cannot be equalized. As air pressure decreases the volume of gases naturally in the body increase, this can happen in the middle ear which is an air filled chamber separating the outer ear from the fluid filled cochlea or inner ear.
The middle ear relies on the eustachian tube (a small canal that connects the middle ear to the back part of the nasal cavities) to equalise pressure and will do this effectively unless there is a blockage. If this cannot happen, a build up of negative pressure in the middle ear will cause the tympanic membrane (ear drum) to retract causing pain and discomfort and if not resolved the tympanic membrane (eardrum) may rupture/perforate. Even worse is that the thin membrane between the tympanic membrane (middle ear) and the cochlea (inner ear) called the round window, may also retract and if this perforates, would lead to leakage of inner ear fluid (perilymph).
Decompression sickness is often more commonly referred to as "the bends”. This disorder is due to the effects of water pressure, the body absorbs nitrogen gas faster as a diver descends than when they are ascending to the surface, therefore if a diver ascends too quickly, nitrogen gas bubbles will form in body tissue rather than being exhaled. The nitrogen bubbles cause decompression sickness and may cause severe pain.
There are several types of Decompression Sickness:
- Type I Decompression Sickness is the least serious form of Decompression Sickness. It normally involves only pain or discomfort around the body and joints, this is not immediately life threatening. It is important to note that symptoms of Type I Decompression Sickness may be warning signs of more serious problems.
- Type II Decompression Sickness is the most serious and can be immediately life-threatening. The main effect is on the nervous system.
Decompression Sickness can manifest itself in many different ways and has many different symptoms, medical attention should always be sought as soon as possible. The most common symptoms are:
- Hearing loss
- Extreme Fatigue
- Joint and Limb Pain
- Tingling / Numbness
- Respiratory Problems
- Vertigo / Dizziness
- Blurred Vision / Headaches
- Ringing of the Ears
- Nausea / Vomiting / Sickness
Immediate treatment may be necessary and may consist of recompression treatment in a recompression chamber. When treating Decompression Sickness the delay in beginning recompression treatment can be the biggest single cause of residual effects.