Epidemiology
- Occurs in High-Altitude Dwellers
- Incidence in Andean Countries: 5-15% of the population residing >3200m (10,500 ft)
- Chronic Mountain Sickness Affects Approximately 2 Million People
Physiology
- Chronic High Altitude-Related Disease (see High Altitude, [[High Altitude]])
- Chronic Hypobaric Hypoxia
- Increased Erythropoietin Production (see Serum Erythropoietin, [[Serum Erythropoietin]])
Diagnosis
Complete Blood Count (CBC) (see Complete Blood Count, [[Complete Blood Count]])
- Polycythemia: hemoglobin >21 g/dL or hematocrit >63%
Arterial Blood Gas (ABG) (see Arterial Blood Gas, [[Arterial Blood Gas]])
- Hypoxemia (see Hypoxemia, [[Hypoxemia]])
Echocardiogram (see Echocardiogram, [[Echocardiogram]])
- Findings
- Pulmonary Hypertension (see Pulmonary Hypertension, [[Pulmonary Hypertension]])
Clinical Manifestations
Cardiovascular Manifestations
Right-Sided Congestive Heart Failure (CHF) (see Congestive Heart Failure, [[Congestive Heart Failure]])
- Epidemiology: may occur
Gastrointestinal Manifestations
- Digestive Complaints
Hematologic Manifestations
Polycythemia (see Polycythemia, [[Polycythemia]])
- Epidemiology
- Physiology
- Clinical
- Polycythemia: hemoglobin >21 g/dL or hematocrit >63%
Neurologic Manifestations
- Depression (see Depression, [[Depression]])
- Fatigue (see Fatigue, [[Fatigue]])
- Headache (see Headache, [[Headache]])
- Sleep Disturbance
- Social Exclusion/Psychological Degradation
Pulmonary Manifestations
Dyspnea (see Dyspnea, [[Dyspnea]])
- Physiology
Pulmonary Hypertension (see Pulmonary Hypertension, [[Pulmonary Hypertension]])
- Epidemiology
- Physiology
- Chronic Hypoxemia (see Hypoxemia, [[Hypoxemia]])
- Clinical
- Dyspnea (see Dyspnea, [[Dyspnea]])
- Hypoxemia (see Hypoxemia, [[Hypoxemia]])
- Right-Sided Congestive Heart Failure (CHF) (see Congestive Heart Failure, [[Congestive Heart Failure]])
Chronic Hypoventilation (see Chronic Hypoventilation, [[Chronic Hypoventilation]])
- Epidemiology
- Physiology
Other Manifestations
- xxx
Treatment
Acetazolamide (Diamox) (see Acetazolamide, [[Acetazolamide]])
- Rationale: carbonic anhydrase inhibitor induces a metabolic acidosis with a secondary increase in ventilation and decreased hypoxemia
- Clinical Efficacy
- Trial of Acetazolamide in Chronic Mountain Sickness in Peru (Am J Respir Crit Care Med. 2005) [MEDLINE]
- Acetazolamide Decreases Hypoventilation
- Acetazolamide Increased Nocturnal SaO2 (by 5%), Decreased Nocturnal Heart Rate (by 11%), and Decreased Sleep Apnea-Hypopnea Episodes (by 74%)
- Acetazolamide Decreased Erythropoietin and Decreased Hematocrit
- Acetazolamide Decreases Hypoventilation
- Peruvian Trial of Chronic Acetazolamide in Chronic Mountain Sickness (Am J Respir Crit Care Med, 2008) [MEDLINE]
- Chronic Acetazolamide (250 mg/day x 3 wks) Improved Erythrocytosis
- Chronic Acetazolamide (250 mg/day x 3 wks) Improved Hypoxemia
- Only Patients Treated for 6 mo Had a Decrease in Pulmonary Vascular Resistance (PVR)
- Treatment Had No Adverse Effects
- Trial of Acetazolamide in Chronic Mountain Sickness in Peru (Am J Respir Crit Care Med. 2005) [MEDLINE]
Phlebotomy (see Phlebotomy, [[Phlebotomy]])
- Clinical Efficacy
- Only Transiently Effective in Relieving Symptoms: however, phlebotomy undesirably decreases the oxygen content in distal tissues, worsening symptoms over time
Supplemental Oxygen (see Oxygen, [[Oxygen]])
- Clinical Efficacy
- May Acutely Improve Symptoms: however, it is expensive, may not be available in high-altitude communities, and is not the best long-term treatment
Relocation to Sea Level
- Indications
- High-Altitude Cerebral Edema (see High-Altitude Pulmonary Edema, [[High-Altitude Pulmonary Edema]]): usually associated with acute high altitude exposure (see High Altitude, [[High Altitude]])
- High-Altitude Pulmonary Edema (see High-Altitude Pulmonary Edema, [[High-Altitude Pulmonary Edema]]): usually associated with acute high altitude exposure (see High Altitude, [[High Altitude]])
- Refractory Chronic Mountain Sickness
References
- Effect of acetazolamide on acute mountain sickness. N Engl J Med. 1968;279(16):839 [MEDLINE]
- Effects of acetazolamide and hypoxia on cerebrospinal fluid bicarbonate. J Appl Physiol. 1968;24(1):17 [MEDLINE]
- Relative effectiveness of acetazolamide versus medroxyprogesterone acetate in correction of chronic carbon dioxide retention. Am Rev Respir Dis. 1983;127(4):405 [MEDLINE]
- Effects of acute and chronic acetazolamide on resting ventilation and ventilatory responses in men. J Appl Physiol (1985). 1993;74(1):230 [MEDLINE]
- Acetazolamide in the treatment of acute mountain Sickness: clinical efficacy and effect on gas exchange. Ann Intern Med. 1992;116(6):461 [MEDLINE]
- Pathophysiology and epidemiology of chronic mountain sickness. Int J Sports Med. 1992 Oct;13 Suppl 1:S79-81 [MEDLINE]
- Acetazolamide: a treatment for chronic mountain sickness. Am J Respir Crit Care Med. 2005;172(11):1427 [MEDLINE]
- Andean, Tibetan, and Ethiopian patterns of adaptation to high-altitude hypoxia. Integr Comp Biol. 2006 Feb;46(1):18-24. doi: 10.1093/icb/icj004. Epub 2006 Jan 6 [MEDLINE]
- Acetazolamide for Monge’s disease: efficiency and tolerance of 6-month treatment. Am J Respir Crit Care Med. 2008 Jun 15;177(12):1370-6. doi: 10.1164/rccm.200802-196OC. Epub 2008 Apr 3 [MEDLINE]