High-altitude pulmonary edema: a collective review

Area of Science:

• Altitude sickness
• Pulmonary medicine
• Environmental health

Background:

• High-altitude pulmonary edema (HAPE) is a life-threatening condition affecting a subset of individuals ascending above 9,000 feet.
• Its exact pathophysiology remains unclear but involves pulmonary vascular changes due to hypobaric hypoxia.
• A subclinical form is common above 14,000 feet, but the incidence of symptomatic HAPE is not well-defined.

Purpose of the Study:

• To review the pathophysiology, risk factors, clinical presentation, diagnosis, and treatment of High-Altitude Pulmonary Edema (HAPE).
• To highlight the importance of prompt recognition and management of HAPE in high-altitude environments.

Main Methods:

• Review of existing literature on High-Altitude Pulmonary Edema (HAPE).
• Analysis of clinical presentations, diagnostic findings (blood gases, chest X-rays), and differential diagnoses.
• Evaluation of treatment modalities and mortality data.

Main Results:

• HAPE presents similarly to pneumonia with symptoms like tachypnea, cyanosis, and cough, often worsening at night.
• Diagnostic indicators include elevated WBC, respiratory alkalosis, low hemoglobin saturation, and bilateral infiltrates on chest X-ray.
• Risk factors include rapid ascent, exertion, previous HAPE, infections, and altitude-related illnesses like Acute Mountain Sickness (AMS).

Conclusions:

• Prompt descent, rest, oxygen, and therapies like EPAP are critical for managing HAPE.
• Mortality rates for HAPE range from 4% to 27%, heavily influenced by the speed of evacuation and treatment.
• Understanding risk factors and clinical signs is essential for preventing and treating this severe altitude illness.