Altitude sickness overview: Difference between revisions

Jump to navigation Jump to search
No edit summary
 
(46 intermediate revisions by 4 users not shown)
Line 1: Line 1:
__NOTOC__
__NOTOC__
{{Altitude sickness}}
{{Altitude sickness}}
{{CMG}}
{{CMG}} {{AE}} {{F.K}}


==Overview==
==Overview==
Every year, thousands of trekkers, skiers, climbers, security forces, rescuers, and others ascend to high altitudes with little or no time for acclimatization. The unacclimatized traveler ascending at such high rate are at risk for developing high altitude illness.  
[[Chronic mountain sickness]] (CMS) is also known as Monge's disease, after its first description in 1925 by [[Carlos Monge]]. [[High Altitude Flatus Expulsion]] was first described by Joseph Hamel in c. 1820. It was rediscovered in 1981 by Paul Auerbach and York Miller. Altitude sickness may be classified according to clinical symptoms and the [[pathological]] changes of principally encroached organs into 2 groups [[acute]] and [[chronic]]. Altitude sickness caused by an increase in [[pulmonary artery]] pressure due to the normal [[pulmonary]] [[vasoconstriction]] induced by [[hypoxia]]. [[Hypoxia]] leads to increase oxygen delivery to the tissues and increases [[ventilation]], [[cardiac output]] and [[Hemoglobin|haemoglobin]] concentrations. These changes improve [[Ventilation-perfusion mismatch|ventilation-perfusion]] matching and [[gas exchange]] and lead to high altitude pulmonary [[hypertension]]. [[Altitude sickness]] is brought on by the combination of reduced air pressure and lower oxygen concentration that occur at high altitudes. Common risk factors in the development of altitude sickness include underlying lung disease, substances or conditions that interfere with acclimatization, previous history of high altitude sickness, lack of acclimatization. There is insufficient evidence to recommend routine [[screening]] for altitude sickness which include cold pressor test, [[heart rate]] variability, [[pulmonary function test]]. The important [[complications]] of altitude sickness are high altitude [[pulmonary edema]] and [[cerebral edema]]. [[Prognosis]] is generally good, and the 5 year [[mortality rate]] of patients with altitude sickness is approximately 12%. Patients with altitude sickness may have a positive history of underlying lung disease and substances or conditions that interfere with [[acclimatization]]. Common [[symptoms]] of altitude sickness include [[headache]], [[dizziness]], [[fatigue]], [[cyanosis]]. Laboratory findings consistent with the diagnosis of altitude sickness include increased the level of [[hemoglobin]], [[hematocrit]] and [[blood urea nitrogen]] and decreased level of [[bicarbonate]], [[creatinine]] and [[PCO2]]. An [[ECG]] may be helpful in the diagnosis of altitude sickness. Findings on an [[ECG]] suggestive of altitude sickness include shortening of R-R interval, shortening of the lengthening of Q-T and in particular for the ST-T flattening and Increase of P wave. X-ray may be helpful in the diagnosis of complications of altitude sickness which include patchy [[alveolar]] infiltrates, predominantly in the right central hemithorax, asymmetric pattern of airspace [[Consolidation (medicine)|consolidation]]. CT scan may be helpful in the diagnosis of complications of altitude sickness [[pulmonary edema]] and it shows patchy [[alveolar]] infiltrates, predominantly in the right central hemithorax. [[Pharmacologic]] medical therapies for altitude sickness include [[acetazolamide]], [[dexamethasone]]. Pharmacologic therapy for [[nausea]] and [[vomiting]] of altitude sickness include [[promethazine]], [[ondansetron]]. Effective measures for the primary prevention of altitude sickness include avoiding [[alcohol]] ingestion, high [[carbohydrate]] in diet, adequate [[hydration]], vigorous [[exertion]] during the first few days at high altitude, oxygen Enrichment.
''Altitude sickness'', also known as ''acute mountain sickness'' (''AMS'') or ''altitude illness'' is a pathological condition that is caused by acute exposure to low air pressure (usually outdoors on high altitudes). It commonly occurs above 2,400 metres (approximately 8,000 feet)<ref>{{cite web | author=K Baillie and A Simpson  | title=Acute mountain sickness| url=http://www.altitude.org/calculators/altitudefacts/altitudefacts.htm | publisher=Apex (Altitude Physiology Expeditions) | accessdate=2007-08-08}} - High altitude information for laypeople</ref>. Acute mountain sickness can progress to [[high altitude pulmonary edema]] (HAPE) or [[high altitude cerebral edema]] (HACE).<ref>{{cite web | author=AAR Thompson  | title=Altitude-Sickness.org| url=http://www.altitude-sickness.org| publisher=Apex  | accessdate=2007-05-08}}</ref> Altitude sickness does not typically affect persons traveling in aircraft, as the cabins of modern airplanes are pressurized. Another rarer type of altitude sickness caused by prolonged exposure to high altitude is [[chronic mountain sickness]] (CMS), also known as Monge's disease, after its first description in 1925 by [[Carlos Monge]]<ref name="pmid1011412">{{cite journal| author=Monge CC, Whittembury J| title=Chronic mountain sickness. | journal=Johns Hopkins Med J | year= 1976 | volume= 139 SUPPL | issue=  | pages= 87-9 | pmid=1011412 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=1011412  }} </ref>. It may develop after many years of living at high altitude. In medicine, high altitude is defined as over 2500 metres, but most cases of CMS occur at over 3000 m. HAFE or High Altitude Flatus Expulsion is a [[gastrointestinal]] syndrome which involves the spontaneous passage of increased quantities of [[rectal gases]] at high altitudes.<ref>Medicine For the Outdoors by Paul S. Auerbach, M.D. © 1999 by Paul S. Auerbach, M.D.</ref> First described by Joseph Hamel in c. 1820. It was rediscovered in 1981 by Paul Auerbach and York Miller.<ref>http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1272559</ref>


Generally, different people have different susceptibilities to altitude sickness. For some otherwise healthy people Acute mountain sickness (AMS) can begin to appear at around 2000 meters (6,500 feet) above sea level such as at many mountain ski resorts. AMS is the most frequent type of altitude sickness encountered. Symptoms often manifest themselves 6 to 10 hours after ascent and generally subside in 1 to 2 days, but they occasionally develop into the more serious conditions. Symptoms are described as headache with fatigue, stomach sickness, dizziness, and sleep disturbance as additional possible symptoms. Exertion aggravates the symptoms.
==Historical Perspective==
[[Chronic mountain sickness]] (CMS) is also known as Monge's disease, after its first description in 1925 by [[Carlos Monge]]. [[High Altitude Flatus Expulsion]] was first described by Joseph Hamel in c. 1820. It was rediscovered in 1981 by Paul Auerbach and York Miller.


[[High altitude pulmonary edema]] ([[HAPE]]) and [[High altitude cerebral edema]] ([[HACE]]) are the most ominous of these symptoms, while acute mountain sickness, retinal haemorrhages, and peripheral edema are the less severe forms of the disease. The rate of ascent, the altitude attained, the amount of physical activity at high altitude, as well as individual susceptibility, are contributing factors to the incidence and severity of high-altitude illness. HAPE is a life-threatening form of non-cardiogenic [[pulmonary edema]] that occurs in otherwise healthy mountaineers at altitudes above {{m to ft|2500}}. Some cases have however been reported also at lower altitudes (between 1500 and 2500&nbsp;m in highly vulnerable subjects), although what makes some people susceptible to HAPE is not currently known. HAPE remains the major cause of death related to high altitude exposure with a high mortality in absence of emergency treatment. HACE is the result of swelling of brain tissue from fluid leakage.
==Classification==
Altitude sickness may be classified according to clinical symptoms and the [[pathological]] changes of principally encroached organs into 2 groups [[acute]] and [[chronic]].


Altitude sickness usually occurs following a rapid ascent and can usually be prevented by ascending slowly <ref>http://www.high-altitude.org</ref>. In most of these cases, the symptoms are only temporary and usually abate with time as altitude acclimatisation occurs. However, in more extreme cases symptoms can be fatal.
==Pathophysiology==
Altitude sickness caused by an increase in [[pulmonary artery]] pressure due to the normal [[pulmonary]] [[vasoconstriction]] induced by [[hypoxia]]. [[Hypoxia]] leads to increase oxygen delivery to the tissues and increases [[ventilation]], [[cardiac output]] and [[Hemoglobin|haemoglobin]] concentrations. These changes improve [[Ventilation-perfusion mismatch|ventilation-perfusion]] matching and [[gas exchange]] and lead to high altitude pulmonary [[hypertension]].


==Causes==
[[Altitude sickness]] is brought on by the combination of reduced air pressure and lower oxygen concentration that occur at high altitudes.
==Differentiating Altitude Sickness from Other Diseases==


<u>High Altitude Categories:</u>
==Epidemiology and Demographics==
The [[incidence]] of altitude sickness is approximately 53,000 per 100,000 individuals worldwide. The [[prevalence]] and [[mortality rate]] of altitude sickness depends on altitude. Patients of all age groups may develop altitude sickness. The [[incidence]] of altitude sickness increases with age; the [[median]] age at [[diagnosis]] is 26-45 years. There is no racial predilection to altitude sickness. The majority of altitude sickness cases are reported in Kilimanjaro, Everest region of Nepal.


{| border="1"
==Risk Factors==
|-
Common risk factors in the development of altitude sickness include underlying lung disease, substances or conditions that interfere with acclimatization, previous history of high altitude sickness, lack of acclimatization.
|Classification||Altitude(mts)||Altitude(feet)
 
|- valign="top"
==Screening==
|High altitude||1,500-3,500 mts||4,921-11,483 feet
There is insufficient evidence to recommend routine [[screening]] for altitude sickness which include cold pressor test, [[heart rate]] variability, [[pulmonary function test]].
|- valign="bottom"
 
|Very high altitude||3,500-5,500 mts||11,483-18,045 feet
==Natural History, Complications, and Prognosis==
|- valign="bottom"
The important [[complications]] of altitude sickness are high altitude [[pulmonary edema]] and [[cerebral edema]]. [[Prognosis]] is generally good, and the 5 year [[mortality rate]] of patients with altitude sickness is approximately 12%.
|Extreme altitude||5,500-8,850 mts||18,045-29,035 feet
 
|}
==Diagnosis==
===History and Symptoms===
Patients with altitude sickness may have a positive history of underlying lung disease and substances or conditions that interfere with [[acclimatization]]. Common [[symptoms]] of altitude sickness include [[headache]], [[dizziness]], [[fatigue]], [[cyanosis]].
 
===Physical Examination===
Physical examination of patients with altitude sickness is usually remarkable for [[headache]], [[nausea]], [[vomiting]] and [[lightheadedness]].
 
===Laboratory Findings===
Laboratory findings consistent with the diagnosis of altitude sickness include increased the level of [[hemoglobin]], [[hematocrit]] and [[blood urea nitrogen]] and decreased level of [[bicarbonate]], [[creatinine]] and [[PCO2]].
 
===EKG===
An [[ECG]] may be helpful in the diagnosis of altitude sickness. Findings on an [[ECG]] suggestive of altitude sickness include shortening of R-R interval, shortening of the lengthening of Q-T and in particular for the ST-T flattening and Increase of P wave.
 
===X Ray===
X-ray may be helpful in the diagnosis of complications of altitude sickness which include patchy [[alveolar]] infiltrates, predominantly in the right central hemithorax, asymmetric pattern of airspace [[Consolidation (medicine)|consolidation]].
 
===CT===
CT scan may be helpful in the diagnosis of complications of altitude sickness [[pulmonary edema]] and it shows patchy [[alveolar]] infiltrates, predominantly in the right central hemithorax.
 
===MRI===
[MRI]] may be helpful in the diagnosis of complications of high altitude [[pulmonary edema]] and it shows increased T2 signal in the [[white matter]] of the [[splenium]] of the [[corpus callosum]].
 
===Other imaging findings===
There are no other imaging findings associated with altitude sickness.
 
===Other diagnostic studies===
There are no other diagnostic studies associated with altitude sickness.
 
==Treatment==
===Medical Therapy===
[[Pharmacologic]] medical therapies for altitude sickness include [[acetazolamide]], [[dexamethasone]]. Pharmacologic therapy for [[nausea]] and [[vomiting]] of altitude sickness include [[promethazine]], [[ondansetron]].
 
===Surgery===
Surgical [[Intervention (counseling)|intervention]] is not recommended for the management of altitude sickness.
 
===Primary Prevention===
Effective measures for the primary prevention of altitude sickness include avoiding [[alcohol]] ingestion, high [[carbohydrate]] in diet, adequate [[hydration]], vigorous [[exertion]] during the first few days at high altitude, oxygen Enrichment.
 
===Secondary Prevention===
There are no established measures for the secondary prevention of altitude sickness.
 
===Future or Investigational Therapies===
In order to help understand the factors that make some individuals susceptible to high altitude pulmonary edema (HAPE), the [[International HAPE Database]] was set up in 2004.<ref>{{cite web | title=International HAPE database  | url=http://www.altitude.org/hape.htm | publisher=Apex (Altitude Physiology EXpeditions) | accessdate=2006-08-10}}</ref> Individuals who have previously suffered from HAPE can register with this confidential database in order to help researchers study the condition.


==References==
==References==
{{reflist|2}}
{{reflist|2}}
{{WikiDoc Help Menu}}
{{WikiDoc Sources}}


[[Category:Disease]]
[[Category:Mountaineering]]
[[Category:Emergency medicine]]
[[Category:Emergency medicine]]
[[Category:Pulmonology]]
[[Category:Pulmonology]]
[[Category:Neurology]]
[[Category:Neurology]]
{{WH}}
{{WS}}

Latest revision as of 13:52, 22 March 2018

Altitude sickness Microchapters

Home

Patient Information

Overview

Historical Perspective

Classification

Pathophysiology

Causes

Differentiating Altitude Sickness from other Diseases

Epidemiology and Demographics

Risk Factors

Screening

Natural History, Complications and Prognosis

Diagnosis

Diagnostic study of Choice

History and Symptoms

Physical Examination

Laboratory Findings

Electrocardiogram

X-ray

Echocardiography and Ultrasound

CT

MRI

Other Imaging Findings

Other Diagnostic Studies

Treatment

Medical Therapy

Surgery

Primary Prevention

Secondary Prevention

Cost-Effectiveness of Therapy

Future or Investigational Therapies

Case Studies

Case #1

Altitude sickness overview On the Web

Most recent articles

Most cited articles

Review articles

CME Programs

Powerpoint slides

Images

American Roentgen Ray Society Images of Altitude sickness overview

All Images
X-rays
Echo & Ultrasound
CT Images
MRI

Ongoing Trials at Clinical Trials.gov

US National Guidelines Clearinghouse

NICE Guidance

FDA on Altitude sickness overview

CDC on Altitude sickness overview

Altitude sickness overview in the news

Blogs on Altitude sickness overview

Directions to Hospitals Treating Altitude sickness

Risk calculators and risk factors for Altitude sickness overview

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1] Associate Editor(s)-in-Chief: Farima Kahe M.D. [2]

Overview

Chronic mountain sickness (CMS) is also known as Monge's disease, after its first description in 1925 by Carlos Monge. High Altitude Flatus Expulsion was first described by Joseph Hamel in c. 1820. It was rediscovered in 1981 by Paul Auerbach and York Miller. Altitude sickness may be classified according to clinical symptoms and the pathological changes of principally encroached organs into 2 groups acute and chronic. Altitude sickness caused by an increase in pulmonary artery pressure due to the normal pulmonary vasoconstriction induced by hypoxia. Hypoxia leads to increase oxygen delivery to the tissues and increases ventilation, cardiac output and haemoglobin concentrations. These changes improve ventilation-perfusion matching and gas exchange and lead to high altitude pulmonary hypertension. Altitude sickness is brought on by the combination of reduced air pressure and lower oxygen concentration that occur at high altitudes. Common risk factors in the development of altitude sickness include underlying lung disease, substances or conditions that interfere with acclimatization, previous history of high altitude sickness, lack of acclimatization. There is insufficient evidence to recommend routine screening for altitude sickness which include cold pressor test, heart rate variability, pulmonary function test. The important complications of altitude sickness are high altitude pulmonary edema and cerebral edema. Prognosis is generally good, and the 5 year mortality rate of patients with altitude sickness is approximately 12%. Patients with altitude sickness may have a positive history of underlying lung disease and substances or conditions that interfere with acclimatization. Common symptoms of altitude sickness include headache, dizziness, fatigue, cyanosis. Laboratory findings consistent with the diagnosis of altitude sickness include increased the level of hemoglobin, hematocrit and blood urea nitrogen and decreased level of bicarbonate, creatinine and PCO2. An ECG may be helpful in the diagnosis of altitude sickness. Findings on an ECG suggestive of altitude sickness include shortening of R-R interval, shortening of the lengthening of Q-T and in particular for the ST-T flattening and Increase of P wave. X-ray may be helpful in the diagnosis of complications of altitude sickness which include patchy alveolar infiltrates, predominantly in the right central hemithorax, asymmetric pattern of airspace consolidation. CT scan may be helpful in the diagnosis of complications of altitude sickness pulmonary edema and it shows patchy alveolar infiltrates, predominantly in the right central hemithorax. Pharmacologic medical therapies for altitude sickness include acetazolamide, dexamethasone. Pharmacologic therapy for nausea and vomiting of altitude sickness include promethazine, ondansetron. Effective measures for the primary prevention of altitude sickness include avoiding alcohol ingestion, high carbohydrate in diet, adequate hydration, vigorous exertion during the first few days at high altitude, oxygen Enrichment.

Historical Perspective

Chronic mountain sickness (CMS) is also known as Monge's disease, after its first description in 1925 by Carlos Monge. High Altitude Flatus Expulsion was first described by Joseph Hamel in c. 1820. It was rediscovered in 1981 by Paul Auerbach and York Miller.

Classification

Altitude sickness may be classified according to clinical symptoms and the pathological changes of principally encroached organs into 2 groups acute and chronic.

Pathophysiology

Altitude sickness caused by an increase in pulmonary artery pressure due to the normal pulmonary vasoconstriction induced by hypoxia. Hypoxia leads to increase oxygen delivery to the tissues and increases ventilation, cardiac output and haemoglobin concentrations. These changes improve ventilation-perfusion matching and gas exchange and lead to high altitude pulmonary hypertension.

Causes

Altitude sickness is brought on by the combination of reduced air pressure and lower oxygen concentration that occur at high altitudes.

Differentiating Altitude Sickness from Other Diseases

Epidemiology and Demographics

The incidence of altitude sickness is approximately 53,000 per 100,000 individuals worldwide. The prevalence and mortality rate of altitude sickness depends on altitude. Patients of all age groups may develop altitude sickness. The incidence of altitude sickness increases with age; the median age at diagnosis is 26-45 years. There is no racial predilection to altitude sickness. The majority of altitude sickness cases are reported in Kilimanjaro, Everest region of Nepal.

Risk Factors

Common risk factors in the development of altitude sickness include underlying lung disease, substances or conditions that interfere with acclimatization, previous history of high altitude sickness, lack of acclimatization.

Screening

There is insufficient evidence to recommend routine screening for altitude sickness which include cold pressor test, heart rate variability, pulmonary function test.

Natural History, Complications, and Prognosis

The important complications of altitude sickness are high altitude pulmonary edema and cerebral edema. Prognosis is generally good, and the 5 year mortality rate of patients with altitude sickness is approximately 12%.

Diagnosis

History and Symptoms

Patients with altitude sickness may have a positive history of underlying lung disease and substances or conditions that interfere with acclimatization. Common symptoms of altitude sickness include headache, dizziness, fatigue, cyanosis.

Physical Examination

Physical examination of patients with altitude sickness is usually remarkable for headache, nausea, vomiting and lightheadedness.

Laboratory Findings

Laboratory findings consistent with the diagnosis of altitude sickness include increased the level of hemoglobin, hematocrit and blood urea nitrogen and decreased level of bicarbonate, creatinine and PCO2.

EKG

An ECG may be helpful in the diagnosis of altitude sickness. Findings on an ECG suggestive of altitude sickness include shortening of R-R interval, shortening of the lengthening of Q-T and in particular for the ST-T flattening and Increase of P wave.

X Ray

X-ray may be helpful in the diagnosis of complications of altitude sickness which include patchy alveolar infiltrates, predominantly in the right central hemithorax, asymmetric pattern of airspace consolidation.

CT

CT scan may be helpful in the diagnosis of complications of altitude sickness pulmonary edema and it shows patchy alveolar infiltrates, predominantly in the right central hemithorax.

MRI

[MRI]] may be helpful in the diagnosis of complications of high altitude pulmonary edema and it shows increased T2 signal in the white matter of the splenium of the corpus callosum.

Other imaging findings

There are no other imaging findings associated with altitude sickness.

Other diagnostic studies

There are no other diagnostic studies associated with altitude sickness.

Treatment

Medical Therapy

Pharmacologic medical therapies for altitude sickness include acetazolamide, dexamethasone. Pharmacologic therapy for nausea and vomiting of altitude sickness include promethazine, ondansetron.

Surgery

Surgical intervention is not recommended for the management of altitude sickness.

Primary Prevention

Effective measures for the primary prevention of altitude sickness include avoiding alcohol ingestion, high carbohydrate in diet, adequate hydration, vigorous exertion during the first few days at high altitude, oxygen Enrichment.

Secondary Prevention

There are no established measures for the secondary prevention of altitude sickness.

Future or Investigational Therapies

In order to help understand the factors that make some individuals susceptible to high altitude pulmonary edema (HAPE), the International HAPE Database was set up in 2004.[1] Individuals who have previously suffered from HAPE can register with this confidential database in order to help researchers study the condition.

References

  1. "International HAPE database". Apex (Altitude Physiology EXpeditions). Retrieved 2006-08-10.

Template:WH Template:WS