Introduction: Pericarditis in pediatric patients is well described, however, the epidemiology of acute, constrictive methicillin-resistant Staphylococcus aureus (MRSA) pericarditis in pediatric patients remains unclear and poses unique challenges to pediatric practitioners. This case illustrates the prompt diagnosis and surgical management of MRSA infective pericarditis in a 5-year-old patient presenting with tamponade physiology without bacteremia and rapid development of constrictive physiology in the setting of a pericardial drain. 

Case Description: A 5-year-old, healthy, male presented hypoxic, hypotensive, and tachycardic to a rural emergency department. Echocardiogram revealed large pleural and pericardial effusions with cardiac tamponade.  Following pericardiocentesis, the patient was intubated, started on antibiotics, and transferred to the tertiary pediatric hospital. He underwent pericardial drain placement. MRSA grew from the pericardial fluid and blood cultures remained negative. An echocardiogram on post-procedure day 2 was consistent with constrictive physiology. A right internal jugular central venous line measured pressures of 21-25 mmHg. Patient’s condition progressively deteriorated and he was taken to the OR for pericardiectomy and epicardial stripping of a thick exudate. 

Discussion: While early diagnoses of cardiac tamponade and constrictive pericarditis can improve morbidity and mortality, there is limited information regarding the diagnosis, management, and treatment of acute, constrictive pericarditis in pediatric patients.  

Advanced imaging is often used to aid in the diagnosis of constrictive pericarditis, however, due to rapid patient deterioration, elevated central venous pressures, and echocardiographic findings consistent with constriction, our multi-disciplinary team elected to proceed with surgical intervention and forgo advanced imaging.

Despite increasing cases of MRSA in pediatric patients, the epidemiology of acute, constrictive MRSA pericarditis remains unclear. Primary, purulent pericarditis is rare amongst the pediatric population, as most are identified to have a concurrent site of infection such as pneumonia, soft tissue or bone infection as the primary source of infection. This is in direct contrast with our patient whose blood cultures remained negative, and no overt source of infection was identified outside of the pericardial fluid.

Prompt initiation of empiric antibiotic therapy for patients with suspected infectious, constrictive pericarditis is beneficial, however, guidelines are not well defined. Throughout our literature review, empiric vancomycin and ceftriaxone were administered in order to cover for MSSA and MRSA, and antibiotic therapy was adjusted once cultures resulted. 

Conclusion: Although many cases of pediatric pericarditis are idiopathic, and infectious etiologies are often secondary to an identifiable source. Here we describe an isolated MRSA infective pericarditis presenting with constrictive physiology without bacteremia. Despite drain placement, constrictive physiology developed rapidly to a thick exudate adhered to the epicardial surface. While multiple imaging modalities are available to diagnose constrictive pericarditis, surgical management is often driven by the clinical course. Pericardiectomy can be safely performed in the pediatric population with prompt resolution of constrictive physiology. In the setting of infectious, constrictive pericarditis from MRSA there are limited data to guide antibiotic therapy; however, early initiation of empiric treatment that provides coverage for MRSA and MSSA is recommended in order to reduce morbidity and mortality from MRSA pericarditis.