Characteristics of Non-postoperative Pediatric Pericardial Effusion: A Multicenter Retrospective Cohort Study from the Pediatric Health Information System (PHIS).

Little is known about the causes and risks of non-postoperative pericardial effusion (PCE) in pediatric patients. We sought to assess the diagnoses most frequently associated with admissions for PCE, and to determine if certain conditions were associated with higher in-hospital mortality and rates of readmission. Nationally distributed data from 44 pediatric hospitals in the 2004-2015 Pediatric Health Information System database were used to identify patients with hospital admissions for International Classification of Disease, Ninth Revision (ICD-9) codes for PCE and/or cardiac tamponade. Children with congenital heart disease were excluded. ICD-9 codes for conditions associated with PCE were grouped into eight categories: neoplastic, renal, autoimmune/inflammatory, pneumonia, viral, bacterial, hypothyroidism, and idiopathic. Multivariable models were used to evaluate odds of in-hospital mortality and readmission within 30 and 90 days. There were 9902 patients who met inclusion criteria. Total in-hospital mortality was 8.2% (n = 813); of those without a neoplastic diagnosis, mortality was 6.5% (n = 493/7543). Idiopathic PCE accounted for the most admissions (36%), followed by neoplasms (24%), pneumonia (20%), and autoimmune/inflammatory disease (19%). In multivariable models, odds of death were highest for neoplasms (adjusted odds ratio 3.83, p < 0.001) and renal disease (adjusted odds ratio 2.86, p < 0.001). Children with a neoplasm, renal disease, and those undergoing pericardiocentesis had the highest rates of readmission at 30 and 90 days. Children admitted with non-postoperative PCE have multiple associated conditions. Neoplasm and renal disease in the setting of PCE are associated with the highest odds of in-hospital mortality among concomitant conditions; children with a neoplasm, renal disease, and those undergoing pericardiocentesis have the highest odds of readmission.