Difference between revisions of "High altitude pulmonary edema"

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*[[High Altitude Medicine]]
 
*[[High Altitude Medicine]]
  
==Source==
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==Sources==
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*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 02:12, 5 January 2016

Background

  • Also known as HAPE
  1. Noncardiogenic pulm edema d/t increased microvascular pressure in the pulm circulation
  2. Most lethal of the altitude illnesses
  3. Occurs in <1/10,000 skiers in Colorado; 2-3% of Mt. McKinley climbers
  4. Typical pt is strong and fit; may not have symptoms of AMS before onset of HAPE
  5. 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)

Workup

Differential Diagnosis

High Altitude Illnesses

Pulmonary Edema Types

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

Treatment

  • 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 pts who had HAPE before
  • Tadalafil 10mg BID 24hr prior to ascent OR Sildenafil 50mg q8hr
  • Salmeterol 125 mcg inhaled BID
  • Acetazolamide (125mg BID for prevention of hypoxia) is not used in acute setting of HAPE

See Also

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

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