High Altitude Pulmonary Edema.

A centrineurogenic etiology for the pulmonary changes of High Altitude Pulmonary Edema HAPE has been established. Respiratory hypoxia leads to the pathological pulmonary complex in unprotected beagles. These pulmonary changes are induced by isolated cerebral hypoxemia. The lungs do not develop this pattern during systemic, respiratory hypoxia, when the brain is perfused with autologous blood at normal oxygen saturation. Denervation of the left lung two months prior to isolated cerebral phyoxemia is protective of that lung, but not the normally innervated right lung, which develops the pathological complex. Directly monitored left atrial pressure ruled out heart failure as contributing to the pulmonary picture. Bilateral excision of the carotid bodies failed to alter the course of the lung complication. This confirms a direct effect of the cerebral hypoxia in the pathogenesis of the pulmonary sequence. The induction of HAPE by isolated cerebral hypoxemia is a universal, species independent phenomenon. This was reproduced in seven species of experimental animal, including primate rhesus monkey. Author Modified Abstract