Difference between revisions of "High altitude pulmonary edema"

(Updated to standard format - will need further cleanup and citing)
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== Background ==
+
==Background==
 
*Also known as HAPE
 
*Also known as HAPE
#Noncardiogenic pulm edema d/t increased microvascular pressure in the pulm circulation  
+
*Noncardiogenic pulm edema d/t increased microvascular pressure in the pulm circulation  
#Most lethal of the altitude illnesses  
+
*Most lethal of the altitude illnesses  
#Occurs in <1/10,000 skiers in Colorado; 2-3% of Mt. McKinley climbers  
+
*Occurs in <1/10,000 skiers in Colorado; 2-3% of Mt. McKinley climbers  
#Typical pt is strong and fit; may not have symptoms of AMS before onset of HAPE  
+
*Typical pt is strong and fit; may not have symptoms of AMS before onset of HAPE  
#Most commonly noticed on the second night at a new altitude  
+
*Most commonly noticed on the second night at a new altitude  
  
 
===Risk Factors===
 
===Risk Factors===
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*Previous history of HAPE
 
*Previous history of HAPE
  
== Clinical Features ==
+
==Clinical Features==
 
*Early  
 
*Early  
 
**Dry cough, decreased exercise performance, dyspnea on exertion, localized rales  
 
**Dry cough, decreased exercise performance, dyspnea on exertion, localized rales  
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**Tachycardia and tachypnea correlate with the severity of illness  
 
**Tachycardia and tachypnea correlate with the severity of illness  
 
**Altered mental status and coma (from severe hypoxemia)  
 
**Altered mental status and coma (from severe hypoxemia)  
 
===Workup===
 
*[[ECG]]
 
**Right strain pattern
 
*[[CXR]]
 
**Progresses from interstitial to localized-alveolar to generalized-alveolar infiltrates
 
*[[ABG]]
 
**[[Hypoxemia]] with [[respiratory alkalosis]]
 
  
 
==Differential Diagnosis==
 
==Differential Diagnosis==
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{{Pulmonary edema types}}
 
{{Pulmonary edema types}}
  
== Treatment ==
+
==Diagnosis==
 +
===Workup===
 +
*[[ECG]] - right strain pattern
 +
*[[CXR]] - Progresses from interstitial → localized-alveolar → generalized-alveolar infiltrates
 +
*[[ABG]] - [[Hypoxemia]] with [[respiratory alkalosis]]
 +
 
 +
===Evaluation===
 +
*Clinical diagnosis
 +
 
 +
==Management==
 
*Immediate descent is treatment of choice - minimize exertion  
 
*Immediate descent is treatment of choice - minimize exertion  
 
*If cannot descend use combination of:  
 
*If cannot descend use combination of:  
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**Consider the medications listed below that are usually used for prevention
 
**Consider the medications listed below that are usually used for prevention
  
== Disposition ==
+
==Disposition==
 
*Admission  
 
*Admission  
 
**Warranted for severe illness that does not respond immediately to descent  
 
**Warranted for severe illness that does not respond immediately to descent  
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*May re-ascend in 2-3 days if mild-moderate symptoms resolved that only required descent as the intervention
 
*May re-ascend in 2-3 days if mild-moderate symptoms resolved that only required descent as the intervention
  
== Prevention ==
+
==Prevention==
*Nifedipine 20mg q8hr or 30mg q12hr while ascending is effective prophylaxis in pts who had HAPE before
+
*Nifedipine 20mg q8hr or 30mg q12hr while ascending is effective prophylaxis in patients with prior episodes of HAPE  
*Tadalafil 10mg BID 24hr prior to ascent OR Sildenafil 50mg q8hr
+
*Tadalafil 10mg BID 24hr prior to ascent '''OR''' Sildenafil 50mg q8hr
 
*Salmeterol 125 mcg inhaled BID
 
*Salmeterol 125 mcg inhaled BID
*Acetazolamide (125mg BID for prevention of hypoxia) is not used in acute setting of HAPE
+
*Acetazolamide 125mg BID for prevention of hypoxia
  
 
==See Also==
 
==See Also==
 
*[[High Altitude Medicine]]
 
*[[High Altitude Medicine]]
 
==Sources==
 
*Yaron M, Honigman B: High-Altitude Medicine, in Marx JA, Hockberger RS, Walls RM, et al (eds): Rosen’s Emergency Medicine: Concepts and Clinical Practice, ed 7. St. Louis, Mosby, Inc., 2010, (Ch) 142: p 1917-1928.
 
  
 
==References==
 
==References==

Revision as of 07:16, 6 March 2016

Background

  • Also known as HAPE
  • Noncardiogenic pulm edema d/t increased microvascular pressure in the pulm circulation
  • Most lethal of the altitude illnesses
  • Occurs in <1/10,000 skiers in Colorado; 2-3% of Mt. McKinley climbers
  • Typical pt is strong and fit; may not have symptoms of AMS before onset of HAPE
  • Most commonly noticed on the second night at a new altitude

Risk Factors

  • Heavy exertion
  • Rapid ascent
  • Cold
  • Excessive salt ingestion
  • Use of a sleeping medication
  • Preexisting pulmonary HTN
  • Preexisting respiratory infection (children)
  • Previous history of HAPE

Clinical Features

  • Early
    • Dry cough, decreased exercise performance, dyspnea on exertion, localized rales
    • Resting SaO2 is low for the altitude and drops markedly w/ exertion (aids in the dx)
  • Late
    • Dyspnea at rest, marked weakness, productive cough, cyanosis, generalized rales
    • Tachycardia and tachypnea correlate with the severity of illness
    • Altered mental status and coma (from severe hypoxemia)

Differential Diagnosis

High Altitude Illnesses

Pulmonary Edema Types

  • Pulmonary capillary wedge pressure <18 mmHg differentiates noncardiogenic from cardiogenic pulmonary edema[1]

Cardiogenic pulmonary edema

Noncardiogenic pulmonary edema

Diagnosis

Workup

Evaluation

  • Clinical diagnosis

Management

  • Immediate descent is treatment of choice - minimize exertion
  • If cannot descend use combination of:
    • Supplemental O2 - Can completely resolve the pulmonary edema within 36-72hr
    • Hyperbaric bag - Gamow Bag
    • Keep pt warm (cold stress elevates pulm artery pressure)
    • Use expiratory positive airway pressure mask
    • Consider the medications listed below that are usually used for prevention

Disposition

  • Admission
    • Warranted for severe illness that does not respond immediately to descent
  • Discharge
    • Progressive clinical and X-ray improvement and a PaO2 of 60mmHg or SaO2>90%
  • May re-ascend in 2-3 days if mild-moderate symptoms resolved that only required descent as the intervention

Prevention

  • Nifedipine 20mg q8hr or 30mg q12hr while ascending is effective prophylaxis in patients with prior episodes of HAPE
  • Tadalafil 10mg BID 24hr prior to ascent OR Sildenafil 50mg q8hr
  • Salmeterol 125 mcg inhaled BID
  • Acetazolamide 125mg BID for prevention of hypoxia

See Also

References

  1. Clark SB, Soos MP. Noncardiogenic Pulmonary Edema. In: StatPearls. Treasure Island (FL): StatPearls Publishing; October 1, 2020.