Initial Treatment of High-Altitude Pulmonary Edema: Comparison of Oxygen and Auto-PEEP

Background: Improvement of oxygenation is the aim in the therapy of high-altitude pulmonary edema (HAPE). However, descent is often difficult and hyperbaric chambers, as well as bottled oxygen, are often not available. We compare Auto-PEEP (AP-Pat), a special kind of pursed lips breathing, against the application of bottled oxygen (O(2)-Pat) in two patients suffering from HAPE. Methods: We compare the effect of these two different therapies on oxygen saturation measured by pulse oximetry (SpO(2)) over time. Result: In both patients SpO(2) increased significantly from 65–70% to 95%. Above 80% this increase was slower in AP-Pat compared with O(2)-Pat. Therapy started immediately in AP-Pat but was delayed in O(2)-Pat because of organizational and logistic reasons. Conclusions: The well-established therapies of HAPE are always the option of choice, if available, and should be started as soon as possible. The advantage of Auto-PEEP is its all-time availability. It improves SpO(2) nearly as well as 3 L/min oxygen and furthermore has a positive effect on oxygenation lasting for approximately 120 min after stopping. Auto-PEEP treatment does not appear inferior to oxygen treatment, at least in this cross-case comparison. Its immediate application after diagnosis probably plays an important role here.