The respiratory effects of progesterone in severe pulmonary emphysema

Abstract

1.1. Daily administration of intramuscular progesterone in oil produced an increase in both the total ventilation and alveolar ventilation in seven patients with severe pulmonary emphysema and in two normal subjects. 2.2. This hyperventilatory effect of progesterone was accompanied by a significant fall in carbon dioxide tension in only three of the seven emphysematous patients studied. 3.3. It seems that the alveolar ventilation must show a greater percentage increase than the total ventilation in order for the carbon dioxide tension to be reduced. 4.4. In three of the seven emphysematous patients studied, the increased ventilation was associated with an increased oxygen consumption. It is believed this increased oxygen consumption was due to increased work of breathing as a result of hyperventilation. 5.5. There was no evidence of a bronchodilator effect of progesterone. 6.6. Although the ventilatory response to carbon dioxide inhalation demonstrated a lower threshold to carbon dioxide during progesterone therapy, the evidence was inconclusive as to whether progesterone actually increased the sensitivity of the respiratory center. 7.7. The one emphysematous patient studied showed less of a response to carbon dioxide inhalation than the normal subjects. This diminished response was not felt to indicate necessarily a decreased sensitivity of the respiratory center, as it may have been due to both the fact that his oxygen consumption doubled and that his total ventilation approached his maximum breathing capacity.