High-Altitude Pulmonary Edema Workup

Updated: Dec 31, 2015
  • Author: Rohit Goyal, MD; Chief Editor: Zab Mosenifar, MD, FACP, FCCP  more...
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Laboratory Studies

Findings on laboratory studies from high-altitude pulmonary edema (HAPE) patients are nonspecific.

Arterial blood gas measurement may show acute respiratory alkalosis. A mild leukocytosis also may be present.

Some studies have demonstrated increase in interleukin-6 (IL-6), interleukin-1 receptor antagonist (IL-1ra), and cross-reacting protein (CRP) in response to high altitude. The systemic increase of these inflammatory markers may reflect considerable local inflammation. [8]


Imaging Studies

Chest radiography in high-altitude pulmonary edema (HAPE) patients reveals bilateral patchy infiltrates.

In one study, stress echocardiography was used to quantitate pulmonary artery systolic pressure responses to prolonged hypoxia and normoxic exercise. [9] The data from the study indicate that individuals who are susceptible to HAPE have abnormal vascular responses not only to hypoxia but also to supine bicycle exercise under normoxic conditions. Thus, this modality may be a useful noninvasive screening method to identify subjects susceptible to HAPE.

Chest ultrasonography was evaluated in one study and showed that the comet-tail technique, which has been shown in cardiogenic pulmonary edema, effectively recognizes and evaluates the degree of pulmonary edema in HAPE patients. [10]


Other Tests

ECG in high-altitude pulmonary edema (HAPE) patients may reveal a right-sided heart strain pattern suggestive of pulmonary hypertension.



Portable hyperbaric chambers (Gamow, CERTEC) are in wide use by trekkers. A physiologic (simulated) descent of approximately 2000 m may be achieved in a few minutes. Patients are typically treated in 1-hour increments. Patients should be closely observed for rebound symptoms after hyperbaric treatments.