Percussion of the abdomen

Definition: The purpose of abdominal percussion is to assess whether the abdominal contents are solid, hollow, air or fluid-filled. With percussion you can also delineate the size of individual organs.

Test procedure: To achieve good percussion sounds place your middle finger firmly flat against the abdomen and strike it with a hammer-like motion with the index or middle finder of the other hand.

Percuss all 9 regions of the abdomen.
Hollow areas should be tympanic sounding whereas areas containing masses or organs will be dull e.g. liver.
Changes in sound such as dullness may indicate masses and these can be percussed and assessed for size.
For instance you can map out the size of the liver by percussing from the middle of the right thorax towards the right costal margin until you hear the dullness of the underlying liver mass and mark the spot.
You also percuss from down-up by starting from the umbilical level until again you reach dullness and note that area.

Test findings: In ascites when the patient is supine there is usually flank dullness evident while the tympanic sounds over the umbilicus region is apparent. Confirm any suspected ascites by asking the patient to lie on their side and after a few moments percuss again. The fluid would have shifted to the side they are lying on and the air travelled to the top side.

Considerations: Monitor the patients face for any signs of discomfort throughout the exam. Enquire if bowel movements are regular. In the case of female patients be aware that you may need to enquire about any possibility of potential pregnancy or any issues relating to the menstrual cycle such as polycystic ovarian syndrome (PCOS)