To the Editor:
Langer et al. demonstrated that a regional pulmonary vascular occlusion is associated with a diversion of ventilation from nonperfused to perfused lung areas.1 This compensation, due to hypocapnic bronchoconstriction, in combination with pneumo-constriction, limits the increase in dead-space ventilation, improves ventilation-perfusion matching, and thus may decrease the work of breathing during spontaneous ventilation. Wheezing occurs with acute pulmonary embolism in patients both with and without previous cardiopulmonary disease.2 Wheezing due to bronchoconstriction thus may be just be a marker or consequence and not the cause of respiratory dysfunction. Since the bronchoconstriction may have beneficial effects, do the authors recommend not treating the wheezing associated with pulmonary embolus, particularly in patients with no previous cardiopulmonary disease, where the wheezing is likely to be caused solely by the hypocapnic bronchoconstriction reflex?
The author declares no competing interests.