A paired ascitic-fluid calculation
A fictional adult with abdominal distension has paired serum and ascitic-fluid samples collected during the same assessment. Serum albumin is 28 grams per liter and ascitic albumin is 10 grams per liter. The team has not yet established the full cause of the ascites, and imaging, cardiac history, infection assessment and liver-disease evaluation remain incomplete. A learner subtracts the values but labels the result as proof that cirrhosis is the only possible diagnosis. Another learner mixes grams per liter with grams per deciliter and reports a tenfold different number. The supervising physician asks for a calculation with consistent units and a statement about what the result can and cannot establish.
1. Calculate the gradient.
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The paired serum-minus-ascites albumin gradient is 28 - 10 = 18 g/L, equivalent to 1.8 g/dL.
2. What mechanism does it support?
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It supports a portal-hypertension mechanism in the appropriate clinical assessment, but does not alone identify cirrhosis as the only possible cause.