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

Define the concept of time of useful consciousness.

This describes the amount of time that once a person becomes hypoxic they can remain conscious enough to recognise what is happening and do something about it

Describe how hypoxia can be treated.

To treat hypoxia; 

Administer Oxygen from an oxygen supply source
Descend the aircraft to 10,000 ft AMSL or below

State the factors that affect the likelihood of suffering from hypoxia.

• Carbon Monoxide
• Cough / cold or chest infection
• Hangover
• Alcohol and drug
• Excessive movement about the aircraft
• Subjection to cold temperatures
• Subjected to G force
• Anemia
• Fatigue
• Smoker 

Describe how hypoxia can be prevented.

• Avoid flying when unwell / chesty
• Avoid G loading
• Avoid hangovers, alcohol, drug use
• Check for anemia
• Avoid fatigue
• Reduce smoking
• Watch for early warning signs
• Avoid excessive movement about the cabin

Explain the relationship between hypoxic onset and both vision and cognitive performance. 

The most complex parts of the brain use the most amount of oxygen, and so will be affected earlier by hypoxia;

resulting in vision loss and reduced cognitive performance 

Explain the reasons hypoxia symptoms are difficult to detect.

The onset can be very subtle and gradual so is not noticed straight away