Altitude Related Disorders

Question 1

3 main types of high altitude disorders

Answer 1

1. acute mountain sickness (AMS)
2. high altitude pulmonary oedema (HAPE)
3. high altitude cerebral oedema (HACE)

Question 2

Cause for all 3 altitude related disorders

Answer 2

chronic hypobaric hypoxia

Question 3

Acute mountain sickness is generally a self-limiting condition. TRUE/FALSE?

Answer 3

TRUE

Question 4

Above what altitude do symptoms of acute mountain sickness begin to develop?

Answer 4

2,500 - 3,000m

Question 5

Over how long do symptoms of acute mountain sickness develop, and how long do they take to subside?

Answer 5

• develop gradually over 6-12 hours
• last a number of days

Question 6

Symptoms of Acute mountain sickness

Answer 6

headache
nausea
fatigue

Question 7

Prevention of acute mountain sickness

Answer 7

• gain altitude at no more than 500 m per day
• acetazolamide causes a metabolic acidosis and compensatory respiratory alkalosis
  => increases RR and improves oxygenation

Question 8

Treatment for acute mountain sickness

Answer 8

descent

Question 9

Above what altitude can HAPE or HACE develop?

Answer 9

> 4000m

Question 10

Mechanism of HAPE developing

Answer 10

hypobaric hypoxia
→ uneven pulmonary vasoconstriction
→ uneven blood flow in the lungs
→ areas of the lung receiving more blood experience an increase in capillary pressure
→ more fluid leakage.

Question 11

How does HAPE present?

Answer 11

With pulmonary oedema-type symptoms

Question 12

Mechanism of development of HACE

Answer 12

Hypoxia
→ cerebral vasodilation
→ elevated cerebral blood volume
→ increased permeability of blood-brain barrier
→ capillaries in the brain more leaky
→ fluid accumulation in the extracellular spaces
→ cerebral oedema

Question 13

How does HACE present?

Answer 13

headache
ataxia
papilloedema

Question 14

Management of HACE

Answer 14

descent
dexamethasone

Question 15

Management of HAPE

Answer 15

descent
nifedipine, dexamethasone, acetazolamide
oxygen if available