What percentage of patients with pulmonary embolism have pulmonary infarction as a complica-tion?

a. Less than 10%
b. Approximately 25%
c. Approximately 40%
d. Approximately 65%

ANS: A
Embolism to the pulmonary circulation produces pulmonary hemorrhage in the ischemic area and infarction (or tissue death from deprivation of blood flow) in fewer than 10% of cases of pulmo-nary embolism. Infarction is less common than thromboembolism because the lung has two blood supplies: the pulmonary arterial circulation and the bronchial circulation.