A 32-year-old male janitor complains of a swollen face during the past week. A CT scan reveals an expanding hematoma in the superior mediastinum. Mediastinal tamponade is most likely to manifest as which of the following?

In mediastinal tamponade, hypotension, dyspnea, cyanosis, and a decrease in pulse pressure will be evident. During inspiration, the pulse pressure is further impeded to cause obstruction to transmitted ACV waves in the neck; in congestive cardiac failure, the ACV waves recorded in the neck are more prominent. Paresis of the arm is unlikely to occur because the lower part of the brachial plexus (T1) passes along the inner border of the first rib to reach the neck.