| High Altitude Pulmonary Edema (HAPE) occurs in young, healthy individuals after 2-3 days at high altitude and is the most common cause of death at high altitude. The only known cure for HAPE is immediate descent, and the underlying pathophysiology of the condition is not well understood. It has been shown that certain individuals are more susceptible to developing the condition. The present study was designed to determine if a difference exists between the profile of volatile compounds in expired breath condensate (EBC), hypoxic ventilatory response (HVR) and pulmonary artery systolic pressure (PASP) in both HAPE and control subjects. Sixteen healthy, male adult subjects were studied and placed into two groups (HAPE and control). HAPE subjects (n=5) had a prior episode of HAPE, whereas control subjects (n=11) had never experienced this condition. On the first day of the protocol, subjects performed pulmonary function, VO2 max, and HVR tests. On the second day of the study, the subjects completed a pre and post hypoxic exposure 20 min EBC collection, supine exercise test with Doppler Echocardiography measurement of PASP and a ninety min hypoxic exposure (12% O2) with measurement of PASP. Results of the study showed that the EBC profile of volatile compounds was significantly different between groups. In addition, this profile was strongly correlated with HVR. Thus, EBC analysis may be capable of predicting HAPE susceptibility, as well as physiological responses to hypoxia. In the future, this technique could be used in the field to determine HAPE sensitivity prior to altitude exposure.;Keywords: HAPE susceptibility, exhaled breath condensate, altitude sickness, hypoxic ventilatory response, pulmonary artery pressure. |
