altitude sickness - university of nevada, reno … sickness colin m. fuller, md, facc, facp. ......

ALTITUDE SICKNESS

Colin M. Fuller, MD, FACC, FACP

Altitude definition

High altitude

1,500m – 3,500m

5,000’ – 11,500’

Very high altitude

3,500m – 5,500m

11,500’ – 18,000’

Extreme altitude

> 5,500m

> 18,000’

High altitude medical problems

Acute hypoxia

Acute mountain

sickness (AMS)

High altitude

pulmonary edema

(HAPE)

High altitude

cerebral edema

(HACE)

Ravenhill (1913) paper in South American

literature

1. Revealed his observation

of people transported from

sea level to 16,000’ by train

in Bolivia.

2. Most all developed mild

symptoms hours after arrival:

poor sleep, HA, anorexia,

lassitude, symptoms

increased with exercise,

decreased with rest.

Resolved over four days,

called it “normal puna.”

Rave

nhill

Ravenhill noted 2 very serious divergences from

normal puna

“Cardiac puna” – ↑ SOB, ↑ pulse, ↑ RR, cyanosis,

occasionally leads to death

“Nervous puna” –

dizziness, difficulty

with gait, delirious;

rare – often fatal

Rave

nhill

Case report of HAPE from Bates, F. Circulation,

25:929, 1962 T.B., 48 y/o physician, experienced

skier and mountaineer in good health, rode from

sea level to 8,500’ (Alta, Utah) over 12°. Skied

vigorously x 2 days between 8,500’ + 10,300’.

2nd night –

c/o SOB +

nonproductive

cough.

HAPE

Next morning, Sx worse. Also c/o N,V, dizziness

+ HA. ASA + codeine: ↓ cough + H.A., but by

noon Sx ↑. Next day, pt barely able to speak 2°

to SOB, cough now produced pink frothy

sputum. Pulse 120, R.R. 50, therefore, pt

referred to local

hospital (4,200’).

HAPE

Admission to hospital:

• apprehensive, breathless, cyanotic

• Pulse 110 BP 130/90 T° 99°F

• Heart-fixed split of S2

• Lungs – basilar

rates

hct = 51 WBC = 9,800

ECG = Sinus tach PO2 = 40

CXR = normal heart size

pulmonary edema

Rest of work-up was (-) for infection, myocardial

infarction, or intrinsic heart disease

Over next 4 days pt. returned to normal status

The following year pt. returned to high altitude +

Sx recurred

AMS – setting

Generally rapid ascent of unacclimatized persons to ≥

2,500m (8,200’) from altitudes below 1,500m (5,000’)

AMS – pathophysiology

Brain edema?

Secondary to ↓ PO2

AMS – physical exam

Not much data

Probably normal

Moderate acute mountain sickness - Rx

Low-flow oxygen, if available

Acetazolamide, 125 to 250 mg b.i.d., with of without

dexamethasone, 4 mg po, IM, or IV q6h

Hyperbaric

therapy or

immediate

descent

AMS – prevention

Slower ascent

Diamox

Past predicts

future

HAPE – mild

Symptoms

DOE

Dry cough

Signs

HR (rest) < 90

RR (rest) < 20

Few rales, if any

Symptoms Signs

Severe DOE HR 90 – 100, Cyanosis, Rales, Ataxia

Weakness

Headache

Cough

HAPE – moderate

Symptoms Signs

Dyspnea at rest HR > 110, RR > 30, Diffuse rales

Productive cough Blood-tinged sputum, Ataxis, stupor

Orthopnea

Extreme weakness

HAPE – severe

HAPE – treatment

Early recognition

O2, Pressure bag

Nifedipine?

HAPE – prevention

Slow ascent

Drugs – not known

Past predicts future

Early diagnosis is key

HAPE – sequelae

1 – 8 days for Sx to subside

• Lungs and circulation – No chronic sequele

• Re-ascent

usually leads

to HAPE again

HAPE on Mt. Everest, 1990

HAPE on Mt. Everest, 1990

HAPE on Mt. Everest, 1990

Before Echo Contrast Injection

After Echo Contrast Injection

HACE – High Altitude Cerebral Edema

Progression of global cerebral signs and symptoms in

the setting of AMS

HACE – pathophysiologyIncreased H2O in brain cells swelling of cells in rigid

box Sx

HACE – setting>11,000

Rare

May occur

with or be

sequel to

HAPE or

severe AMS

HACE – historySevere HA; Hallucinations; Considerable dizziness

Difficulty with respirations; Staggering; Double vision

Delirium; Paralysis; Proceeding to coma + death

HACE – physical exam

Not much data

Poor coordination

Mental status abnormalities

HACE – prevention

Slow ascent

Early diagnosis: clumsy skier

Drugs – none known to be of prophylactic value

HACE – treatment

Recognition

Descent

Dexamethazone

O2

Pressure bag

Other high altitude medical

problems

• Disordered sleep

• Retinopathy

• UV keratitis

• Peripheral edema

• Pharyngitis/Bronchitis

• HAFE

• Thromboembolic

problems

Retinal hemorrhage (R.H.)

Setting:

20 – 30% ascending ≥ 14,000’

Appears to be exacerbated by

strenuous exercise

R.H. – pathophysiology

Etiology not clear

No correlation with

1) Headache

2) Speed of ascent

3) Sx of AMS

R.H. – history

Usually Asymptomatic

Sudden loss or blurring

of vision in one eye

R.H. – physical

exam

Ophthalmoscope

necessary

R.H. – treatment

Descent

Drugs – none known

R.H. – prevention

None known

Periodic breathing - RxAcetazolamide, 62.5 to 125 mg at bedtime as needed

Ultraviolet keratitis (snow blindness)

One week S/P UV

keratitis

Summit of Everest

Advisability of exposure to high altitude –

no extra risk

Young/old, Fit/unfit

Low risk pregnancy

Controlled hypertension

Obesity

Controlled seizure disorder

Diabetes

Psychiatric disorder

Mild COPD, Asthma

Neoplastic diseases

Inflammatory diseases

Post-CABG (no angina)

Advisability of exposure to high altitude –

caution

Moderate COPD

Angina

Compensated CHF

High risk pregnancy

Sleep apnea

Sickle cell traits

Troublesome arrhythmia

Advisability of exposure to high altitude –

contraindicated

Sickle cell anemia with Hx of crisis

Severe COPD

Pulmonary hypertension

CHF not well controlled

Cerebrovascular disease

Questions? Comments?

Thank you!