Ascites: Physical Methods of Examination of a Patient with Ascites
Ascites is the pathological accumulation of free fluid within the peritoneal cavity.
- It is most commonly due to portal hypertension in liver cirrhosis, but may also result from:
- Malignancy
- Tuberculosis
- Heart failure
- Pancreatic disease
- Nephrotic syndrome
I. General Inspection
Look for:
- Abdominal distension with flanks bulging out.
- Shiny, stretched skin over the abdomen.
- Everted umbilicus.
- Dilated abdominal veins (e.g., caput medusae in portal hypertension).
- Respiratory difficulty due to upward pressure on the diaphragm in tense ascites.
II. Palpation
A. Fluctuation Test
- Used for moderate to large ascites.
- Place one hand on one side of abdomen, give a sharp tap on the opposite side.
- Feel for an impulse transmitted through the fluid.
B. Fluid Thrill (Fluid Wave Test)
- Ask patient (or assistant) to place the edge of a hand on the midline (to stop skin transmission).
- Tap on one flank and feel the transmitted wave on the opposite flank.
- Positive in massive ascites.
IV. Percussion
A. Shifting Dullness
- Helps detect ≥500 mL of fluid.
- With patient supine, percuss from the midline to the flank:
- Resonant → dullness appears over fluid.
- Ask the patient to turn to the side:
- The dull area shifts → confirms free fluid.
This is the most sensitive physical test for moderate ascites.
B. Horse Saddle / Umbilical Resonance Sign
- Central abdomen remains resonant (bowel floats), while flanks are dull (fluid collects laterally).