Purulent Pericarditis: Acute Infections and Chronic Complications

Hospital Physician January 2008 P urulent (or suppurative) pericarditis is defined as an infection of the pericardial space that produces pus that is found on gross examination of the pericardial sac or on tissue microscopy. In most cases, pericardial infection does not produce a purulent effusion. Viral infection, which together with “idiopathic” pericarditis account for 90% of pericarditis cases,1 rarely produces purulent effusions and is typically self-limited, with only a small effusion that is asymptomatic and resolves spontaneously. In contrast, bacterial infections of the pericardium are relatively uncommon but are much more likely to produce purulent effusions and to proceed to cardiac tamponade and pericardial constriction.2,3 Purulent pericarditis occurs almost exclusively as a secondary infection in patients with serious underlying disease, including patients with AIDS and those undergoing hemodialysis, thoracic surgery, and chemotherapy.4–7 Prompt diagnosis is important as purulent pericarditis requires specific therapy targeting the causative agent. However, recognizing purulent pericardial infection in a patient with multiple comorbidities can be clinically challenging. In addition, bacterial pericarditis has a high mortality rate despite appropriate therapy (30%–50%), with the majority of deaths due to cardiac tamponade.4,8 This article reviews the structure and function of the pericardium, the etiology of infectious pericarditis with a focus on causes of purulent infections, and the diagnosis and treatment modalities for pericarditis and its potential sequelae.