Large pericardial effusion after cardiac surgery: role of echocardiography in diagnosis and management.

We performed M-mode and two-dimensional (2-D) echocardiograms prospectively in 140 patients an average of eight days after open heart surgery. Large pericardial effusions occurred in 13 patients; three had complete circumcardiac pericardial effusion, four had local anterior adhesions, five had extensive anterior adhesions (posterior loculated effusion), and one had a large loculated pericardial effusion contiguous to the right atrium. In five patients with tamponade, the effusion was drained, with immediate reversal of symptoms and signs of tamponade. In the other eight patients, who had no deterioration in cardiovascular status, the effusion was not drained; instead, these patients were treated medically with indomethacin and observed with serial echocardiograms, and the effusions eventually disappeared. The most consistent echocardiographic differences between the five patients with and the eight patients without tamponade were that patients with tamponade had larger posterior pericardial effusions, more severe left atrial compression, and more indentation of the right atrial wall. Echocardiography plays an essential role in diagnosis and management of large pericardial effusions after open heart surgery. Patients with large pericardial effusions who are clinically stable need only medical management, including serial echocardiograms, but drainage is indicated if the cardiovascular or respiratory status worsens. Certain echocardiographic findings indicate a high probability of tamponade.