The fluid wave test is a relatively simple test that is used to aid in the diagnosis of ascites. It is often used in conjunction with the test for shifting dullness.
Performing the Test
- Have the patient lie in the supine position.
- Have the patient use the ulnar surface of one of their hands to push along the midline of the abdomen.
- Place your hand flat against the patients flank on one side, use your other hand to tap the contralateral flank sharply.
- The test is positive if the tap generated on flank of the abdomen can be felt clearly on the other side.
- The fluid wave test has been criticized as being insensitive and unfortunately only moderately specific. One group, for example, has reported a sensitivity of only 0.50 and a specificity of 0.82.
- Bickley LS, Szilagyi PG. Bates’ Guide to Physical Examination and History Taking. 10th ed. Philadelphia, PA: Wolter Kluwer Health; 2009.
- Catau EL, Benjamin SB, Knuff TE, Castell DO. The Accuracy of the Physical Examination in the Diagnosis of Suspected Ascites. JAMA. 1982; 247: 1164-1166.