3. AMS acute mountain sickness and its treatment.ppt

Acute mountain sickness

1. Acute mount
ain sickness
Santosh Baniya, MD
Diploma in Mountain Medicine
Mountain Medicine Society of Nepal

2. Altitude sickness
•Spectrum of illnesses that result of body’s
inability to acclimatize results in altitude
sickness
•May affect nervous or/and respiratory system
•Various forms of altitude illness:
–Acute mountain sickness (AMS)
–High altitude cerebral edema (HACE)
–High altitude pulmonary edema (HAPE)

3. Acute Mountain Sickness (AMS)
•Definition:
–Self limiting neurologic syndrome affecting
individuals going to high altitude characterized by
headache and one of the following symptoms:
•Nausea or poor appetite
•Dizziness
•Fatigue
•Sleep disturbance
•Usually occurs after 6-24 hours of ascent!

4. Incidence
•Very common condition in high altitude
•Affecting upto 60-70% of travellers
–An overall incidence of 43% in trekkers reaching the aid
post at Pheriche (4343 m) (Hackett and Rennie, 1979).
–Pilgrims to 4380 m to a sacred lake Gosainkunda incurred
a 68% incidence of AMS (Basnyat et. al. 2000)
–Increasing awareness of AMS has led to a lower
incidence of AMS (Gaillard et. al. 2004, Vardy et. Al.
2005).

5. Risk factors
•Rapid ascent to altitude
–>500m/night and lack of rest days after >1000m
•Over exertion
•Past history of acute mountain sickness
•Dehydration
•Individual susceptibility
•SEX and AGE:
–Young > Elderly but Male = Female

6. Pathophysiology
•Hypobaric hypoxia  Dilation of cerebral
vessels  Increase in blood supply to brain 
Vasogenic cerebral edema/raised ICP

7. Symptoms
•Headache (compulsory!) and one of the
following:
•Nausea or poor appetite
•Dizziness
•Fatigue
•Sleep disturbance

8. Lake Louise Scoring,1993
Symptom No symptom Mild IntensityModerate
Intensity
Severe/
Incapacitating
Headache 0 1 2 3
Nausea/
Vomiting
0
Good appetite
1
Poor appetite or
nausea
2
Moderate
nausea or
vomiting
3
Severe
incapacitating
nausea and
vomiting
Fatigue/
Weakness
0 1 2 3
Dizziness 0 1 2 3
Difficulty
sleeping
0
Slept well as
usual
1
Did not sleep
well as usual
2
Woke many
times, poor
night’s sleep
3
Could not sleep
at all

9. Nepali translation

10. •A diagnosis of AMS likely if:
–A gain in altitude > 2500 m registered during the
past 3 days
–Headache and one additional symptom present
–A total score of at least 3 is achieved
•Severity:
–Mild AMS: LLS 3-5
–Moderate-Severe AMS: LLS >5

11. Differential Diagnosis
•Altitude related:
–High altitude headache
– ?Early HACE
•Travel related:
–Dehydration
–Effects of heat and cold
–Infections – meningitis, malaria, etc
•Alcohol, drugs, etc
•Migraine headache

12. Recent Update
•Lake louise score (2018)
–Mild: 3-5
–Moderate: 6-9
–Severe: 10-12
•Excluded sleep!
•Recommended for research purposes!

13. Treatment
•Mild AMS:
–Relatively harmless condition
–Consider a rest day; No further ascent
–Rest/No unnecessary exertion
–Drink plenty of fluids
–Acetazolamide (250 mg BD)
–Analgesics: Paracetamol, Ibuprofen, Aspirin
•Differentials: Dehydration, Headache.

14. •Moderate-Severe:
–Immediate descent:
•800-1,000 meters or altitude free of symptoms
–Acetazolamide 250 mg BD
–Analgesics: Paracetamol, Ibuprofen, Aspirin
–Other symptomatic management
–Low flow oxygen if available (only in some cases!)

15. •Consider dexamethasone in severe AMS cases
–Dexamethasone: oral or IM or IV
•Descend with company (partner, guide,
porter)
•Plan for evacuation in some situations to be
considered!

16. Prevention
•Gradual Ascent:
–>500m/night and lack of rest days after >1000m
–Recommendation Grade 1B
•Acetazolamide:
–Dose:125 mg BD (Adults)
–Ped: 2.5 mg/kg BD
–Recommendation Grade 1A (travelers with
moderate-high risk for AMS)

17. •Dexamethasone:
–Dose: 2 mg 6 hourly or 4 mg 12 hourly
–Not recommended in children!
–Note: Very high dose i.e. 4 mg 6 hourly indicated
in high risk situations like
•Military and search & rescue personnel being airlifted
to >3500m with immediate performance of physical
activities but shouldn’t be used except in these limited
circumstances!
–Recommendation Grade 1A (travelers with
moderate-high risk for AMS)

18. •Ibuprofen:
–Can be used for the prophylaxis if acetazolamide
and dexamethasone contraindicated
–Dose: 600 mg TDS
–Recommendation Grade 2B
•Inhaled budesonide:
–Shouldn’t be used for prophylaxis
–Recommendation Grade 1C

19. •Paracetamol:
–Shouldn’t be used for prophylaxis
–Recommendation Grade 1C
•Hypoxic tents:
–Can be used for facilitating acclimatization and
prevention of AMS if long exposure can be
undertaken regularly
–Recommendation Grade 2B

20. THANK YOU!