Describe the symptoms of barotrauma.

Pain in the areas of trapped gasses:

• Abdominal pain
• Sinus / facial pain and
• Dental pain / toothache
• Ear pain 

Explain the causes of barotrauma.

When the pressure changes due to climbing or descending, the gases expands and contracts, this takes places when:

• Flying
• Diving
• Pressure from explosion

Define barotrauma.

Barotrauma is caused by the expansion of trapped gases in the body cavities due to changes in the pressure between ambient and semi-closed or closed cavities in the body. 

The applicable physical law is Boyle’s law. The law states that the volume (V) of gas is inversely proportional to its pressure (P), with temperature (T) remaining constant, i.e. P α 1/V

Areas affected by entrapped gasses include ears, sinuses, teeth, gut, and lungs

Describe the differences between hyperventilation and hypoxia

The early symptoms of hyperventilation can be the same as those of hypoxia – always treat as if it is hypoxia as this is a life threatening condition 

Describe how hyperventilation can be treated.

Place a paper bag over the mouth and try to get the person to regulate their breathing

Use polystyrene coffee cup or cupped hands if no paper bag available

This can help to build up CO2 in the blood again

Describe the symptoms of hyperventilation

• Rapid shallow breathing
• Light headedness
• Numbness and tingling of hands and feet and around the mouth
• Hand muscles can spasm
• Pain
• Fainting
• Flushed face 

Explain the causes of hyperventilation.

• Hypoxia
• Excessive worry, anxiety, fear,
• Pain
• Loud noise
• Vibration
• Excessive heat
• Airsickness
• Straining against G forces 

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Define hyperventilation.

Hyperventilation is also sometimes referred to as overbreathing

It can be a symptom of hypoxia or a separate condition

A higher than normal level of carbon dioxide is breathed out with each breath – reducing the acidity level of the blood and subsequent physiological changes

Explain oxygen paradox.

This describes the effects of giving oxygen to someone who is moderately hypoxic

They get a temporary worsening of symptoms
This will pass quickly, it is not a good idea to take the oxygen away 

State the approximate time of useful consciousness at the following altitudes..

10,000ft

In an ideal situation pilot hypoxia should not occur at 10,000ft

14,000ft

30 mins 

 

18,000ft

15- 30 minutes

FL150 (15,000 ft; 4,550 m)	30 minutes or more
FL180 (18,000 ft; 5,500 m)	20 to 30 minutes
FL220 (22,000 ft; 6,700 m)	5-10 minutes
FL250 (25,000 ft; 7,600 m)	3 to 6 minutes
FL280 (28,000 ft; 8,550 m)	2.5 to 3 minutes
FL300 (30,000 ft; 9,150 m)	1 to 3 minutes
FL350 (35,000 ft; 10,650 m)	30 secs to 1 minute
FL400 (40,000 ft; 12,200 m)	15 to 20 seconds
FL430 (43,000 ft; 13,100 m)	9 to 15 seconds
FL500 (50,000 ft; 15,250 m)	6 to 9 seconds