The optimal treatment of large pericardial effusions remains controversial. Some physicians advocate routine pericardial drainage in all patients, while others argue that these procedures offer no benefit unless cardiac tamponade is present. Mercé and associates analyzed patient records to identify any diagnostic or therapeutic benefit to draining a large pericardial effusion as part of routine initial treatment in patients with pericardial effusion without cardiac tamponade.

Records of all patients who were treated at a hospital in Spain for large pericardial effusion without cardiac tamponade over a six-year period were reviewed. A large effusion was defined as an echo-free space during diastole of at least 20 mm, as recorded on echocardiogram. Patients with chronic effusions and those who were suspected of having a purulent effusion were excluded from the study.

The diagnostic yield of pericardiocentesis or pericardial biopsy was evaluated. Hospital protocol was followed for the management of patients with acute pericardial disease; pericardiocentesis was performed on patients who had a cardiac tamponade, a suspected purulent pericarditis or a chronic large effusion that persisted for at least three months. Surgical drainage and pericardial biopsy were performed in patients whose tamponade had relapsed after initial pericardiocentesis and in those whose clinical illness persisted three weeks after hospital admission.

Seventy-one patients with large pericardial effusions were included in the analysis. Of the 13 patients who met the study protocol criteria for pericardial drainage, only one was diagnosed following the procedure. In the 58 patients who did not meet the protocol criteria, 13 underwent a pericardial procedure anyway. Ten patients underwent one of the procedures for medical reasons; three underwent a procedure for diagnostic reasons. However, no other specific diagnoses were obtained.

A total of 24 patients underwent pericardiocentesis and in only one was a specific diagnosis obtained. Of the two pericardiotomies performed, only one yielded new information, bringing the total diagnostic yield of pericardiocentesis and surgical biopsy to 7 percent. Follow-up data were obtained in 68 of the 71 patients (95 percent) for a median of 10 months. During follow-up, five patients underwent pericardial procedures, but none of these led to new diagnoses. The effusions resolved within weeks without any intervention in 38 of the 40 patients in whom pericardial drainage was not performed and who were evaluated during follow-up.

The authors conclude that the use of pericardial procedures does not effectively increase diagnostic yield or improve resolution of large pleural effusions. Routine drainage is not warranted in the initial management of patients with large pericardial effusions, unless cardiac tamponade is present or purulent effusion is suspected.