there is no lower extremity edema. Multiple spider
angiomata are present.
Ascites is the most common complication of
cirrhosis, occurring in 50% of patients within 10
1 Diagnosis based on history and physical
exam may be obvious when there is massive fluid
accumulation and the abdomen is tense; however,
in many cases, diagnosis can be difficult, particu-
larly in obese patients. The most useful finding is
the presence of shifting dullness, which has a
sensitivity of 77% and specificity of 72%.2 Other
signs, such as puddle sign, are less accurate for
diagnosis. When ascites is suspected, diagnostic
paracentesis is mandatory to determine the etiol-
ogy. Ascites analysis provides invaluable informa-
tion, and paracentesis has a low complication rate,
even in the presence of thrombocytopenia and
3 In developed countries, most cases
of ascites are due to cirrhosis, but other etiologies
must be considered because the differential diag-
nosis is broad (Table 1).
The initial ascites fluid evaluation should include
assessment of albumin and total protein concentrations, cell count with differential, and culture. An
algorithmic approach can be used to reliably classify the underlying etiology (Figure;1). The serum-ascites albumin gradient (SAAG), calculated as albuminserum – albuminascites, is a good initial diagnostic
4 A SAAG of 1. 1 g/dL or greater is consistent
with ascites due to portal hypertension or heart
failure. Ascites due to cirrhosis will also have a total
protein less than 2.5 g/dL, and cardiac ascites has
a total protein of 2.5 g/dL or greater. A SAAG below
1. 1 g/dL may indicate malignant ascites or infection
and should be investigated with additional tests
such as ascites cytology, acid-fast staining and culture, amylase, triglycerides, bilirubin, and abdominal
imaging to identify potential cancer.
Spontaneous bacterial peritonitis (SBP) occurs
in 25% of patients with cirrhosis and ascites, and
SBP can be asymptomatic.
5, 6 Therefore, a cell
count and culture should be performed every time a
paracentesis is done for low-protein ascites. An ascites polymorphonuclear cell count of 250 cells/µL
or greater with a positive culture is diagnostic of
SBP. An elevated cell count with a negative culture
is termed culture-negative neutrocytic ascites. Approximately 35% of these patients will have a positive culture on repeated paracentesis;
they should be considered an SBP equivalent.
Table 1. Differential Diagnosis of Ascites
Acute liver failure
Sinusoidal obstruction syndrome
Postoperative lymphatic leak
Reproduced with permission from Runyon BA. Management of adult patients with ascites due to cirrhosis: update 2012. Alexandria (VA): American
Association for the Study of Liver Diseases; 2013.