AvMed

Question 1

what is the composition of the atmosphere

Answer 1

atmosphere 0-300,000 ft

21% Oxygen, 79% nitrogen and trace of CO2 and other gases (Argon and Ozone)

Atmosphere pressure is approx 1000mb at sea level and the partial pressure of Oxygen is 160mm HG (Mercury)

Question 2

what is the pressure of oxygen at sea level, 8000 and 16000ft

Answer 2

sea level 160 mm Hg
8000ft 118.7 mm Hg
18000ft 79.8 mm Hg

In other words the atmosphere becomes less dense as we climb and the result is the partial pressure of oxygen at 18000 ft is 1/2 of that at sea level.

Question 3

What causes the onset of hypoxia

Answer 3

altitude
duration
rate of ascent
physical exertion
cold

‘the rate of its affect depends on how it is induced’

Question 4

hypoxia general

Answer 4

body sensitive to deprivation of oxygen (either in quality or partial pressure)

25% reduction in oxygen pressure (equivalent to 8,000ft cabin alt) produces detectable impaired mental performance

Question 5

what are the symptoms of hypoxia

Answer 5

flushed
cyanosis
increase rate of breathing
gas expansion
tingling sensations (pins and needles)
light headedness
ear discomfort
impaired judgement vision and motor skills

Question 6

what is the time of useful consciousness

Answer 6

Rapid decompression at the maximum altitude for the A400M is around 15-30 seconds

the higher you go the lower the time gets

Question 7

how long would you stay conscious without any oxygen to the brain

Answer 7

6-8 seconds

4 mins irreversible damage

Question 8

how can you treat somebody with hypoxia

Answer 8

put on 100% Oxygen as soon as possible at a low cabin altitude

Question 9

what is respiration

Answer 9

the exchange of oxygen through the lungs in to the blood

Question 10

precautions to be taken during pressure changes

Answer 10

keep trying to clear your ears
otherwise you could end up with what is known as ‘ear block’ or ‘ottic barotrauma’

don’t eat too much gas forming foods

don’t fly for 24 hours after dental work

Question 11

cavities in the body that contain gas

Answer 11

sinuses (expand and contraction of Eustachian Tube)
Middle ear cavities (as above)
teeth fillings
guts
joints

Question 12

what are the dangers with flying with a head cold

Answer 12

can’t clear ears and equalise pressure in the eustachian tube

Question 13

Noxious substances- routes of entry into the body

Answer 13

Inhalation
ingestion
Skin absorption
inoculation
injection

Question 14

actions in the event the cockpit contamination

Answer 14

immediately run the smoke and fumes drill and don FFQDM 100% oxygen

fit FFQDM to portable bottle

Question 15

what are the causes of hyperventilation

Answer 15

excessive ventilation causing an imbalance of CO2

caused by:

anxiety (fear of flying)
normal response to hypoxia
rise in temperature
pressure breathing

Question 16

what are the symptoms of hyperventilation

Answer 16

tingling
unreality
dizziness
muscle spasms

Question 17

how to treat somebody who is hyperventilating

Answer 17

put on 100% Oxygen as soon as possible at a low cabin altitude

Breathe through pursed lips, as if you are whistling, or pinch one nostril and breathe through your nose. It is harder to hyperventilate when you breathe through your nose or pursed lips, because you can’t move as much air.

Question 18

what is the bends (decompression sickness)?

Answer 18

too many nitrogen bubbles in the body expanding due to exposure of lowered atmospheric pressure.

Can be affect those that have recently dived using aqualung or have conducted ground pressurisation tests (GE)

Question 19

how to treat the bends (decompression sickness)

Answer 19

100% Oxygen at as low a cabin alt as possible

lay flat of possible

Question 20

what are the symptoms of the bends

Answer 20

aching muscles or joints
tingling of skin
muscle weakness
poor coordination
loss of sensation
confusion
pain
collapse

Question 21

rapid decompression

Answer 21

passengers masks auto deploy at 14000 ft in normal mode

or 16000 ft in high mode

masks can be manually deployed from the load master workstation or the flight deck

Question 22

causes of rapid decompression

Answer 22

failure of the airframe

failure of the pressurisation system

Question 23

Why do oxygen bottles last longer at altitude?

Answer 23

When you’re in a high-altitude environment, the barometric pressure causes air molecules to expand, so each breath you take contains fewer oxygen molecules. Oxygen Plus products directly solves this “large air molecule” problem by instantly delivering pure enriched oxygen to your cells

Question 24

medical flying restrictions

Answer 24

inoculations, and vaccinations- normally 12 hour restriction

general, spinal or epidural- 48 hours

acupuncture- SMO authority 12 hours

hypnotherapy- SMO authority plus nil flying while under treatment

donating blood- 36 hours

eye dialated- 24 hours

pressurisation- 12 hours after aqualung
24 hours of more than 10 metres
12 hours after ground pressurisation