Key Points
- Use the highest‑yield diagnostic test early; do not let testing delay time‑critical therapy.
- Set objective targets and reassess frequently.
- Plan definitive source control or disease‑specific therapy when indicated; document follow‑up and patient education.
Algorithm
- Suspect HAPE at altitude with dyspnea at rest and hypoxemia; minimize exertion/cold exposure.
- Give oxygen and begin descent; consider portable hyperbaric bag if descent delayed.
- Start nifedipine; monitor and continue descent until symptoms resolve; counsel on prevention for future ascents.
Clinical Synopsis & Reasoning
Noncardiogenic pulmonary edema occurring 2–5 days after rapid ascent above ~2500–3000 m with dyspnea at rest, cough, and hypoxemia. Immediate descent and supplemental oxygen are primary; add nifedipine and consider portable hyperbaric therapy when descent is delayed; avoid exertion and cold exposure.
Treatment Strategy & Disposition
Stabilize ABCs. Initiate guideline‑concordant first‑line therapy with precise dosing and continuous monitoring. Escalate to advanced/procedural interventions based on explicit failure criteria. Define ICU, step‑down, and ward disposition triggers; involve specialty teams early.
Epidemiology / Risk Factors
- Risk varies by comorbidity and precipitants; see citations for condition‑specific data.
Investigations
| Test | Role / Rationale | Typical Findings | Notes |
|---|
| Pulse oximetry and exam | Diagnosis | Resting hypoxemia with crackles | Improves with oxygen/descent |
| CXR (if available) | Support | Patchy alveolar edema without cardiomegaly | — |
| Rule out pneumonia/PE/CHF | Differential | Fever absent; no cardiomegaly | Clinical context |
High-Risk & Disposition Triggers
| Trigger | Why it matters | Action |
|---|
| Worsening hypoxemia/cyanosis at altitude | Life-threatening | Immediate descent; oxygen; nifedipine |
| Neurologic symptoms suggesting HACE | Coexistent severe illness | Dexamethasone; urgent descent |
| No improvement with rest/oxygen at altitude | Progression risk | Portable hyperbaric bag or evacuation |
| Underlying cardiopulmonary disease | Severe course | Lower threshold for evacuation |
| Remote location/limited resources | Delayed care | Plan rapid transport |
Pharmacology
| Medication/Intervention | Mechanism | Onset | Role in Therapy | Limitations |
|---|
| Immediate descent and oxygen (or hyperbaric bag) | Definitive | Minutes | Reverses hypoxemia | — |
| Nifedipine SR 30 mg PO q12h (or 60 mg daily) | Pulmonary vasodilator | Hours | Adjunct for HAPE | Monitor BP |
| PDE‑5 inhibitors (tadalafil) or beta-agonists (inhaled) (selected) | Adjuncts | Hours | Prevention/adjunct in recurrent HAPE | Evidence limited |
Prognosis / Complications
- Outcome depends on timeliness of diagnosis and definitive therapy; monitor for complications.
Patient Education / Counseling
- Provide red‑flag education, adherence guidance, and explicit return precautions; arrange timely specialty follow‑up.
References
- WMS/CDC guidance on high-altitude illness (HAPE) — Link