The Ryanair flight from Dublin to Croatia that had to make an emergency landing in Frankfurt recently led to some dramatic headlines. Following a sudden loss in cabin pressure, 33 passengers were treated in hospital, with some bleeding from their ears. Tweeted pictures from inside the plane also showed blood in used oxygen masks.
A sudden descent from an altitude above 30,000ft caused barotrauma; the dramatic change in pressure is too much for the eardrum, causing it and some surrounding small blood vessels to rupture.
For comfort and safety, aircraft cabins are pressurised to an altitude of somewhere between 5,000 to 8,000 feet which is lower than pressure at sea level. As a plane climbs, the air in the inner ear rises to a greater pressure than the cabin because it is still the same pressure as when the aircraft left the ground, so the eardrum bulges out. Talking or swallowing allows the pressure in the inner ear to slowly equal that of the cabin pressure at cruise level.
When the plane descends, the air pressure in the cabin begins to increase towards that at sea level, while the inner ear remains at the lower cruise-level pressure, and so the eardrum pushes inwards. Yawning or drinking helps open the Eustachian tube – which runs from your middle ear to the back of the nose – to allow the pressure in the inner ear to equalise with that outside the ear.
Intense pain
So, for most of us, this gradual change in middle-ear pressure causes nothing more than transient discomfort. But when the aircraft pressurisation system fails suddenly, it forces the pilots to initiate a rapid descent to a level (about 10,000 feet) where passengers can breathe without oxygen from masks. The reason for the rapidity is the limited supply of oxygen in individual masks. However the rapid descent puts extreme pressure on the ear, causing intense pain. Passengers whose eardrums perforate under the intense pressure are rewarded with pain relief, but are left with a torn eardrum.
The good news is that most eardrums heal and close over slowly without any medical intervention. However a perforation can affect hearing. The extent of hearing loss can vary greatly. Tiny perforations may only cause minimal loss of hearing. Larger perforations may affect hearing more severely. Also, if the tiny ear bones (ossicles) are damaged in addition to the eardrum then the hearing loss will be much greater.
With a perforation, you are at greater risk of developing an ear infection. This is because the eardrum normally acts as a barrier to bacteria that may otherwise get into the middle ear.
Torn eardrum
A torn eardrum will usually heal by itself within 6-8 weeks. It is a skin-like structure and, like skin that is cut, it will usually heal. It’s best not to swim until the eardrum has healed.
If a perforated drum does not heal by itself, then surgery is an option, especially if hearing-loss persists. However many people have a small permanent perforation with no symptoms or significant hearing loss.
Pressure changes in flight means the capacity of the blood to carry oxygen falls by up to 10 per cent
Teeth can also become sore during flights as air in the fillings and around the nerves expands and contracts. And the gas in our bowels isn’t immune to rising and falling pressure. As the aircraft climbs this gas expands, then on descent it becomes compressed again, leading to discomfort and possible social embarrassment.
Pressure changes in flight means the capacity of the blood to carry oxygen falls by up to 10 per cent. This could be a problem if you have a narrowing of the coronary arteries, heart failure or a low blood count. And people with obstructive airways disease may develop dangerously low levels of oxygen in the blood stream when flying.
Barotrauma while flying affects about 5 per cent of people; passengers on the Ryanair flight were unfortunate to experience a higher rate than this.