Pulmonary Edema Fluid Protein in High-Altitude Pulmonary Edema

To the Editor.—  The ratio of edema fluid protein to serum protein is a measurement used to differentiate hydrostatic from permeability edema. Since it was demonstrated that highaltitude pulmonary edema (HAPE) is noncardiogenic,^1,2 HAPE has been classified as a type of permeability edema. The only previous protein ratio reported in HAPE, however, was 0.6,³ which is between that expected for hydrostatic (<0.5) and permeability (>0.7) edemas.⁴ This measurement may have been flawed, since a tracheal specimen was used, which was probably diluted with other airway secretions. Recently, Schoene et al^5,6 lavaged the lungs of persons with HAPE as well as controls and demonstrated a 60-fold higher total protein level in the HAPE lavage fluid. Because of the lavage technique, the dilution with normal saline precluded determination of the total protein ratio. We wish to report protein measurements of undiluted edema fluid from a patient with HAPE.