The Bottom Line: Three guidelines are most useful when determining if a patient has ascites (Williams and Simel, 1992, p.2648):
- The most useful findings for ruling out ascites are negative histories of ankle swelling or increased abdominal girth, and the inability to demonstrate bulging flanks, flank dullness, or shifting dullness.
- The most powerful findings for making the diagnosis of ascites are a positive fluid wave, shifting dullness, or peripheral edema.
- The puddle sign is difficult to perform and uncomfortable for patients and is not sensitive to small amounts of ascites. It should not be performed.
Reference: Williams JW Jr, Simel DL. The rational clinical examination. Does this patient have ascites? How to divine fluid in the abdomen. JAMA. 1992 May 20;267(19):2645-2648.
Summary: Free fluid in the abdominal cavity is ascites. When clinically detectable, ascites may indicate underlying heart failure, liver disease, nephrotic syndrome, or malignancy. Williams and Simel (1992) use three clinical examples to illustrate how to diagnose ascites in the clinical exam and why it’s important:
- Eliciting the symptoms and signs of acites.
- Patient history: Examiner should ask about recent ankle edema, weight gain, or change in abdmoinal girth, as well as a history of liver disease or congestive heart failure.
- Physical exam: Inspection for bulging flanks, percussion for flank dullness, a test for shifting dullness, and a test for a fluid wave.
- Accuracy of history and symptoms for ascites.
- The clinical history distinguishes patients with high and low probabilities for ascites. Ascites is unlikely when patients report no increase in abdominal girth, and it’s very unlikely in male patients who report no history of recent ankle swelling.
- Accuracy of signs for ascites.
- The finding of a fluid wave, shifting dullness, or peripheral edema increased the likelihood of ascites the most.
- The absence of bulging flanks, flank dullness, shifting dullness, or peripheral edema decreased the likelihood of ascites the most.