Cirrhosis, cancer, heart failure, tuberculosis, and dialysis account for 97% of cases of ascites, the accumulation of fluid within the peritoneal cavity. Paracentesis is performed when the ascites is new or the cause of the ascites is unclear (diagnostic tap) or when the patient becomes symptomatic (abdominal pain, shortness of breath, fever) (therapeutic tap). Gross appearance of peritoneal fluid provides a clue to the cause of the ascites. Uncomplicated ascitic fluid in cirrhosis is transparent and yellow. Ascitic fluid can be completely clear if the bilirubin is normal. Turbid or cloudy fluid suggests infection (peritonitis) (see Figs. 25.60 and 25.61). Milky fluid has a high triglyceride level and is considered chylous ascites. Pink or bloody fluid is due to a “traumatic tap,” which clears over time, or malignancy, which is heterogeneous.
Bacterial Peritonitis. Cloudy ascetic fluid in a patient with a new diagnosis of cirrhosis. Cell count of 375 polymorphonuclear lymphocytes (PMNs)/mL suggests bacterial peritonitis. (Photo contributor: Lawrence B. Stack, MD.)
Bacterial Peritonitis. Slightly cloudy peritoneal dialysis fluid in a pediatric patient with 150 PMNs/mL suggests bacterial peritonitis in a peritoneal dialysis patient. (Photo contributor: Lawrence B. Stack, MD.)
Management and Disposition
Spontaneous bacterial peritonitis (SBP) requires intravenous antibiotics and hospital admission. Patients undergoing paracentesis of greater than 5 L should consider albumin replacement of 6 to 8 g per liter of fluid removed.
Cirrhosis is the cause of 80% of ascites.
A neutrophil count of greater than 250/mm3 suggests SBP, and antibiotics should be started.
A neutrophil count of greater than 100/mm3 suggests SBP in continuous ambulatory peritoneal dialysis patients.
Albumin infusion should be considered for paracentesis of greater than 5 L.
Albumin dose is 6 to 8 g per liter of fluid removed
Most SBP is caused by Escherichia coli and Klebsiella.