- Patient lies on his back with thighs flexed
- Place the left hand of the examiner over the left lumbar region of the patient.
- Either the patient or a third person (in the case of a child patient) will put his ulnar border of right hand vertically over the midline of the abdomen and then flick or tap gently the right lumbar region with the right hand.
- A fluid thrill or a pulsation is felt by the hand placed on the opposite lumbar region.
- The purpose of keeping the assistants hand is to dampen any impulse that may be transmitted through the fat of the abdominal wall.
- Fluid thrill is present when fluid collection in the peritoneal cavity is > 2 litres.
- Absence of fluid thrill and shifting dullness or any of them, does not exclude diagnosis of ascites.
Fluid thrill is present in the presence of fluid in the peritoneal cavity whether it is encysted or free,
fluid thrill may be found in.
- Ascites
- Ovarian cyst.
- Hydramnios
- Rarefy in large hydronephrosis.
- Obesity (false positive)
- Large amount of fluid (at least 2 litres fluid is necessary to elicit fluid thrill).
- Fluid should remain under tension.
- Fluid thrill may not be present if there is small collection of fluid or the fluid is not present undertension
Fluid thrill is not a definite sign for ascites
How to elicit fluid thrill in the presence of massive splenomegaly or hepatomegaly with ascites ?
- This is often very difficult to form an opinion regarding fluid thrill in the presence of hepatosplenomegaly
- You should not place the palm over the enlarged organ, rather one should tap from that side and the palpating hand is kept on the other side (patient s hand remains vertically in the mldllne).
- If there is gross hepalosplenomcgaly. fluid thrill often remains inconclusive