the lungs at altitude

Question 1

PIGas =

Answer 1

Patm x FiGas

Question 2

death zone

Answer 2

• defined as over 8000 metres

* altitude above which it is difficult to sustain life without added O2

Question 3

sea level

Answer 3

• Altitude = 0m
• Atmospheric pressure = 100KPa
• PiO2 = 0.20 x 100 = 20KPa

Question 4

normal blood gases

Answer 4

PaO2 10.5 - 13.5 KPa
PaCO2 4.5 - 6.0 KPa
pH 7.3 - 7.44

Question 5

lungs at altitude

Answer 5

Normal response 
Hypoxia leads too ….
•	Hyperventilation at 10000ft altitude 
•	Increases minute ventilation 
•	Lowers PaCO2 
•	Alkalosis initially 
•	Tachycardia 
Adaptive changes 
•	Multiple
•	alkalosis compensated by renal bicarbonate excretion