Altitude

Question 1

Altitude injury threshold

Answer 1

Altitude injury threshold Altitude injury starts >2500m

Question 2

Barometric pressure 5500m

Answer 2

Barometric pressure 5500m At 5500m barometric pressure is halved (500 milibar) and resting O2 sats may be 80%

Question 3

Acetazolamide mechanism

Answer 3

Acetazolamide mechanism Acetazolamide works by promoting renal bicarb excretion causing acidosis causing ↑RR

Question 4

HACE incidence

Answer 4

HACE incidence High Altitude Cerebral Oedema (HACE) occurs in 2-3% of people above 5000m

Question 5

HACE mechanism

Answer 5

HACE mechanism HACE: Leaky cerebral capillaries lead to CNS/Cerebellar dysfunction and can be fatal

Question 6

HACE treatment

Answer 6

HACE treatment HACE Rx: immediate descent (500-1000m), O2, 8mg PO/IV Dexamethasone, chamber, Evac

Question 7

HAPE incidence

Answer 7

HAPE incidence High Altitude Pulmonary Oedema (HAPE): 2% above 4000m, associated with rapid ascent

Question 8

HAPE presentation

Answer 8

HAPE presentation HAPE presents with SOB, worsening bubbly cough, and crackly chest sounds.

Question 9

HAPE treatment

Answer 9

HAPE treatment HAPE Rx: immediate descent (500-1000m), O2, Nifedipine SR 20mg PO QDS, Salbut/CPAP

Question 10

Mountain drugs

Answer 10

Mountain drugs Mountain Drugs: O2, Acetazolamide (AMS), Dexamathasone (HACE), Nifedipine (HAPE)

Question 11

Altitude and contact lens

Answer 11

Altitude and contact lens Altitude also associated with contact lens microbial keratitis. Tx= Ofloxacin eye drops