Altitude Flashcards
Define altitude
the height of an object or point in relation to the sea or ground level (3000m)
True or false: High altitude has decreased temperature and pressure, but increased radiation.
True
What is defined as high altitude? (2 possible answers)
3000-6000m
or
1250-3500m
What is defined as low altitude?
Below 1250m
A peak of a mountain is 6000m above sea level. What altitude classification does this fit
Severe or Extreme
What are the dalton’s law values?
- O2 20.93%
- CO2 0.03%
- N2 79.04%
- Pressure= 760mmHg (sea level)
What is Dalton’s law
The partial pressures of oxygen = fractional concentration x total gas pressure
Define hypoxia
The inadequate supply of oxygen to respiring tissue
WHat are the two types of hypoxia, affected by pressure
normobaric or hypobaric.
Define the O2 Cascade
A reduction in PO2 causes a decrease in pressure for gas exchange. O2 sats fall as altitude increases, due to a decrease in this oxygen cascade of pressure.
Describe Acute Mountain Sickness
Headache, nausea, fatigue
Caused by ascending faster than 500/m a day/vigorous exercise
Describe High Altitude Pulmonary Oedema
Accumulation of fluid in the lungs, breathlessness, fever and coughing frothy spit
After 2-3 days at altitude >2500m. Fatal in hours.
Describe High Altitude Cerebral Oedema
Severe headache, vomiting, confusion, coma
Increase in blow flow to brain is normal. But, if vessels are damaged, fluid may leak out.
Describe the impact of altitude on long and short distance events
Short distances perform better at altitude, due to less air resistance, whereas longer distances perform worse at altitude, due to less O2 pressure, and decreased efficient utilisation of O2.
Describe the effect of altitude on the body- minute ventilation path
As altitude increases: ppo2 decreases –> increased Ve increasing co2 removal. However, hypocapnia, decreases Ve again.
Describe the effect of altitude on the body- ph path
The increased minute ventilation, causes an increase in ph as the co2 is removed. This increases bicarb excretion, causing a fluid shift. This decreases stroke volume and increases Q
Describe the effect of altitude on the body- Arterial Oxygen Saturation
This decreases causing both: an increase in hypoxic pulmonary vasoconstriction (increasing BP),and increase in EPO, HB and HtC and decreases Hb affinity and unloading
What is the immediate respiratory effect of high altitude
Hyperventilation
What are the 4 main long term effects of altitude
- Increased O2 carrying capacity
- Decreased plasma volume
- Increased RBC concentration
- Increased Hb synthesis
How long does it take to adapt to altitude
It takes 2 weeks to adapt to 2300m altitude, and 1 week for every further 610m increase.
Which long term effect variable affects the other 3 the most
EPO increase causes the increase in Hb, HtC and CaO2
