Considerable variability exists in the sepsis workup of febrile infants with suspected RSV infection at our site. Concomitant UTIs are common in febrile, RSV-infected infants.

Giant intraabdominal cysts masquerading as ascites are not uncommon. We present a unique case of a giant intraabdominal pseudocyst that resulted in acute abdominal compartment syndrome, leading to anuria and acute renal failure. A 52-year-old woman with known severe cardiac dysfunction presented with generalized edema, marked abdominal distension, and decreased urine output. She was initially presumed to have congestive heart failure with refractory ascites. She became completely anuric. A diagnosis of intraabdominal compartment syndrome from a giant cyst was ultimately made after careful review of her abdominal imaging. Urgent drainage and subsequent marsupialization of the giant pseudocyst resulted in immediate diuresis and a subsequent return to her baseline renal function. As this case illustrates, differentiation of pseudoascites from true ascites may be difficult in a clinical setting or using laboratory studies. A clear differentiation can usually be made using imaging studies, mainly magnetic resonance imaging, computerized axial tomography, or ultrasound. To our knowledge, this is the first case report of a nonrenal pseudocyst or cyst leading to acute renal failure from extrinsic compression. Abdominal compartment syndrome needs to be considered in the differential diagnosis of patients with acute renal failure and presumed large-volume ascites.