Drive - altitude and depth

Question 1

What is the PiO2 at sea level?

Answer 1

21 KPa

Question 2

How many feet up is extremely high altitude classed as?

Answer 2

18,000 feet

Question 3

What is the fraction of inspired oxygen?

Answer 3

0.21 ALWAYS!

Question 4

What is the atmospheric pressure at sea level?

Answer 4

100KPa

Question 5

What happens to the pressure as altitude rises?

Answer 5

Pressure decreases

Question 6

Describe the normal response of the body to increased altitude:

Answer 6

Hypoxia leads to hyperventilation

Increased minute ventilation

Lowers PaCO2

Tachycardia

Initially Respiratory alkalosis (which is then compensated for by renal bicarbonate excretion)

Question 7

What is acute mountain sickness caused by?

Answer 7

A recent ascent to over 2500m

Question 8

What is the cure for high altitude sickness?

Answer 8

Can only be treated with descent

Question 9

What is the cure for high altitude pulmonary oedema?

Answer 9

Oxygen and descent

Question 10

How does pressure change as depth increases? (and at what rate)

Answer 10

It increases, every 10m water = 1atm

Question 11

What is decompression illness and why does this occur?

Answer 11

When inert bubbles form in the tissues. Occurs when you ascend at a rate that exceeds the bodies capacity to clear the excess gas (as proportionally more gas dissolves in the tissues at depth)