Abstract
We have previously reported the first case with primary pulmonary hypertension (Chest 74: 299) responding well to long term administration of oxygen. This case has been doing well for eight years with nocturnal oxygen administration. The following case differed from the previous one because it did not respond to oxygen in the acute stage but benefited by long term oxygen administration.
A 10 year-old boy with primary pulmonary hypertension did not respond to oxygen and administration of phentolamine resulted in abrupt rise of pulmonary arterial pressure by more than 30% during cardiac catheterization. He was subsequently treated with long term administration of oxygen with substantial improvement (NYHA calss IV to II). On physical examination pulmonary arterial thrust and right ventricular lift became faint and right atrial sound disappearred althought serial ECGs and chest X-rays showed no remarkable changes. After five months of stability, the amount of oxygen administered became far less than expected and he deteriorated rapidly after an episode of influenza. The patient died three months later due to intractable right heart failure.
Autopsy revealed typical pathological changes of primary pulmonary hypertension including plexiform pulmonary ateriopathy and severe right ventricular hypertrophy. The left side of the heart was intact without any shunt or valvular disease. Pulmonary parenchyma and airway were intact and there was no bronchiolo-alveolar lesion suggesting oxygen pneumonitis.
We are now treating four cases of primary pulmonary hypertension with home oxygen therapy all are in good physiological condition. Long term oxygen therapy has been shown to be safe and effective without any noticeable deleterious effects such as systemic hypotension or paradoxical increase of pulmonary arterial pressure which may be seen during vasodilator treatment. This is the treatment of choice for primary pulmonary hypertension.
