High altitude pulmonary edema. Study of 21 cases

BACKGROUND: The effect of altitude on subjects between 8 to 22 and 23 to 51 years, that resided at sea level, or in the highlands, and developed altitude lung edema, is presented in series of 21 prospective registered patients at 4,800 to 5,000 m altitude in the Andes mountains of Ecuador. PATIENTS, MATERIAL AND METHODS: The 21 sick patients were evaluated at 2 h and at 8 h after exposition to the high altitude. They were immediately evacuated from the high altitudes. Clinical and radiological methods were used. The statistical analysis was performed with chi(2) test with Yates correction and relative risk. RESULTS: The younger patients tended to develop illness with a higher frequency (p < 0.01). The place of residence influenced the development of the illness only for the group of persons between the ages of 23 to 51 years (p < 0.03); and also in comparing all of the subjects from the coast with those from the highlands. CONCLUSIONS: A inverse relationship was found between the age and the possibility of the development of altitude pulmonary edema, possibily due to a basic incrementation of the pressure of the pulmonary artery, or because of a relative immaturity of the adaptative mechanisms. The place of residence was significantly associated with a higher frequency of pulmonary edema in persons between the ages of 23 to 51 years.