Yes.

The data now favor an intravascular rather than an endobrochial lesion. We had mentioned early on that the patient's findings could be explained by a blockage of lung perfusion, which would cause autoregulatory bronchoconstriction in the affected area and reduce ventilation of that area. This decrease in ventilation could yield the decreased breath sounds and constricted volume seen on the right side in this patient.

The constricted volume would show up in pulmonary function tests as a "restrictive" defect, as was seen in this patient (the comparably decreased Vital Capacity and FEV1). The residual ventilation to this non-perfused area would appear as excess dead space and, of course, the major effect of such a lesion would be to reduce markedly the effective surface area of the lung.

Be aware that pulmonary artery blockage does not necessarily lead to pulmonary infarction. The lung has a second blood supply (the bronchial arteries) which is derived from a separate source. Though smaller in volume than the pulmonary arterial tree, the bronchial arteries can supply the lungs metabolic needs.