High altitude pulmonary edema: Difference between revisions
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*Early | *Early | ||
**Dry cough, decreased exercise performance, dyspnea on exertion, localized rales | **Dry cough, decreased exercise performance, dyspnea on exertion, localized rales | ||
**Resting SaO2 is low for the altitude and drops markedly with exertion (aids in the | **Resting SaO2 is low for the altitude and drops markedly with exertion (aids in the diagnosis) | ||
*Late | *Late | ||
**Dyspnea at rest, marked weakness, productive cough, cyanosis, generalized rales | **Dyspnea at rest, marked weakness, productive cough, cyanosis, generalized rales | ||
**Tachycardia and tachypnea correlate with | **Tachycardia and tachypnea correlate with severity of illness | ||
**Altered mental status and coma (from severe hypoxemia) | **Altered mental status and coma (from severe hypoxemia) | ||
==Differential Diagnosis== | ==Differential Diagnosis== |
Revision as of 21:52, 12 July 2016
Background
- Also known as HAPE
- Noncardiogenic pulm edema due to 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 patient is strong and fit; may not have symptoms of altered mental status 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 hypertension
- 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 with exertion (aids in the diagnosis)
- Late
- Dyspnea at rest, marked weakness, productive cough, cyanosis, generalized rales
- Tachycardia and tachypnea correlate with 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 patient 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.