Evaluation of ascitic fluid in two steps starting with serum-to-ascites albumin gradient and white cell count can be a cost effective approach. This allows separation of cirrhosis with uncomplicated ascites from other conditions requiring more tests for identification.
serum-to-ascites albumin gradient in g/dL =
= (serum albumin in g/dL) - (ascites albumin in g/dL)
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Serum-to-Ascites Albumin Gradient
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Interpretation
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>= 1.1 g/dL
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diseases associated with portal hypertension
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< 1.1 g/dL
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diseases not causing portal hypertension
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The WBC count is >= 500 per µL:
(1) peritoneal carcinomatosis (13 of 14)
(2) cardiac ascites (4 of 5)
(3) cirrhosis with peritonitis (17 of 18)
Two step approach:
(1) If albumin gradient is >= 1.1 g/dL and the WBC count is < 500 per µL, then diagnosis cirrhosis or liver carcinoma without peritonitis or carcinomatosis. No additional testing is required.
(2) If the albumin gradient is < 1.1 g/dL and/or the WBC count >= 500 per µL, then order additional studies such as culture or cytology depending on the patient's clinical diagnoses and status.
Additional tests to consider performing in addition to culture and cytology:
(1) serum LD, ascites fluid LD,
(2) ascites fluid glucose,
(3) ascites fluid total protein
(4) arterial blood lactate, ascites fluid lactate
(5) arterial blood pH, ascites fluid pH
(6) ascites fluid cholesterol
