In Vivo Demonstration of Small-Airway Bronchoconstriction Following Pulmonary Embolism!

Small-airway bronchoconstriction following massive autologous pulmonary embolism was documented with simultaneous microradiographic and bronchial-pressure measurements. Three groups of dogs were employed, using aged, fresh, and inert (agarose) clots as emboli. Bronchoconstriction of airways 0.3–3.0 mm in diameter was demonstrated in all three groups, indicating that mechanical vascular obstruction is a prominent factor in initiating airway dimensional change. Bronchoconstriction was usually rapid in onset, with early resolution. Differences in response among the three study groups suggest that there are variations in the mechanical as well as the humoral properties of emboli.