High altitude pulmonary edema: Difference between revisions
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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 | |||
*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=== | ===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) | ||
==Differential Diagnosis== | ==Differential Diagnosis== | ||
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{{Pulmonary edema types}} | {{Pulmonary edema types}} | ||
== | ==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 | *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 | *Acetazolamide 125mg BID for prevention of hypoxia | ||
==See Also== | ==See Also== | ||
*[[High Altitude Medicine]] | *[[High Altitude Medicine]] | ||
==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
- Acute mountain sickness
- Chronic mountain sickness
- High altitude cerebral edema
- High altitude pulmonary edema
- High altitude peripheral edema
- High altitude retinopathy
- High altitude pharyngitis and bronchitis
- Ultraviolet keratitis
Pulmonary Edema Types
Pulmonary capillary wedge pressure <18 mmHg differentiates noncardiogenic from cardiogenic pulmonary edema[1]
- Cardiogenic pulmonary edema
- Noncardiogenic pulmonary edema
- Negative pressure pulmonary edema
- Upper airway obstruction
- Reexpansion pulmonary edema
- Strangulation
- Neurogenic causes
- Iatrogenic fluid overload
- Multiple blood transfusions
- IV fluid
- Inhalation injury
- Pulmonary contusion
- Aspiration pneumonia and pneumonitis
- Other
- High altitude pulmonary edema
- Hypertensive emergency
- ARDS
- Flash pulmonary edema
- Immersion pulmonary edema
- Hantavirus pulmonary syndrome
- Missed dialysis in kidney failure
- Naloxone reversal
- Negative pressure pulmonary edema
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
- 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
- ↑ Clark SB, Soos MP. Noncardiogenic Pulmonary Edema. In: StatPearls. Treasure Island (FL): StatPearls Publishing; October 1, 2020.