RISK FACTORS
* In general, the faster the ascent and the higher, the more likely a person will experience symptoms of altitude illness
* Chronic illness
* Lack of conditioning
GENERAL MEASURES :
* Therapy must be tailored to fit severity of disease and may be constrained by the environment
* Definitive treatment is to descend to a lower altitude. Dramatic improvement accompanies even modest
reductions in altitude (as little as 1,000 feet [305 m]).
* Oxygen, given continuously at 1-2 liters per minute helps relieve symptoms. For severe symptoms, ontinuous
oxygen should be administered and descent to a lower altitude is mandatory.
* ACUTE MOUNTAIN SICKNESS :
* Stop ascent. Acclimatize at the same altitude; give acetazolamide 125 -250 mg orally two times a day, or descend 460 m (1500 ft) or more until symptoms resolved
HIGH ALTITUDE PUL EDEMA & HIGH ALTITUDE CEREBRAL EDEMA :
* Patient must be treated by immediate evacuation to a lower altitude. Occasionally, however, foul weather,
lack of transportation or long distances prevent immediate evacuation. In these cases, supportive measures, such as bedrest and oxygen, will help.
* Hyperbaric therapy is another effective and practical alternative when descent is not possible. A portable
hyperbaric chamber, the (Gamow bag,) made of fabric and weighing only 8 pounds (3.6 kg) can be
inflated to 2 pounds per square inch (13.8 kPa) using a foot pump. This is equivalent to a drop in altitude
of about 5,000 feet (1524 m). Improvement is usually immediate after being placed in the hyperbaric chamber.
* If patient is hospitalized, rule out any other pulmonary disease fi rst, provide adequate oxygen (possibly
by intubation or positive end-expiratory pressure [PEEP]), bed rest, diuresis if needed and postural drainage
DRUG(S) OF CHOICE
* Aspirin or codeine can be used to relieve the headache.
Antibiotics, if infection is present.
* Both dexamethasone and acetazolamide have been used to treat patients with severe symptoms of AMS( AC. MOUNTAIN SICKNESS).
Dosage of dexamethasone is 8 mg initially, followed by 4 mg every six hours by mouth. Doses of acetazolamide of up to 1.0 g/day may be required for effective treatment.
* Dexamethasone may be effective in mild cases of HAPE( HIGH ALTITUDE PUL. EDEMA ), but this has not been proven
* Diuretics have not been useful
* Corticosteroids should be given even though their effectiveness is questionable
PREVENTION/AVOIDANCE :
- General guidelines :
* Staged ascent: โStagingโ is the process of remaining at an intermediate altitude (6600 to 9800 feet [2012
to 2988 m]) for a few days before attempting the ultimate altitude
* Conventional prescription for avoiding altitude illness is to allow one day to ascend and acclimatize each 1,000 feet (305 m) from elevations of 10,000 to 14,000 feet (3,048 to 4,267 m). Two days per 1,000 feet (305 m) at elevations above 14,000 feet (4267 m).
* Sleeping elevation - climberโs maximum โclimb high and sleep lowโ is a prudent practice for anyone going
above 12,000 feet (3656 m)
* Adequate hydration - dehydration increases the likelihood of and worsens the symptoms of AMS
* Good physical conditioning
* Consider carrying a supply of oxygen
- DRUG PROPHYLAXIS :
* Acetazolamide (if patient has a history of problems at altitude and/or plans a rapid ascent to above 8,000
feet [2438 m] in a car or airplane). Dosage is usually 250 mg orally twice daily, starting 24 hours before ascent and continuing for two to three days while at altitude. Anyone with a known drug allergy to sulfa should avoid acetazolamide.
* Dexamethasone may signifi cantly reduce the incidence and severity of acute mountain sickness. The
dosage is 2 to 4 mg every six hours, begun the day of the ascent, continued for three days at the higher
altitude, then tapered over fi ve days. Adverse side effects are uncommon.
POSSIBLE COMPLICATIONS
* Without treatment, HACE can cause motor and sensory deficits, seizures and coma
* HAPE may progress to cyanosis and respiratory distress syndrome
* Patient may experience high altitude retinal hemorrhage
* (HARH) - can cause visual changes, but is usually asymptomatic
EXPECTED COURSE/PROGNOSIS :
* Mild to moderate AMS resolves over 1-3 days. Patients may resume ascent once symptoms subside.
* HAPE and HACE patients can expect complete recovery, if there is no underlying disease. Should not
resume ascent.
* Problems are more likely to recur in people who have had one or more attacks
AGE-RELATED FACTORS:
Pediatric: Children under 6 are more susceptible than adults
Geriatric: Elderly more likely to have chronic conditions (coronary artery disease, congestive heart failure, chronic obstructive pulmonary disease) that may be exacerbated at altitudes of 6000-8000 feet (1829-2438 m)
Others: Women in premenstrual phase are more vulnerable