Shifting dullness is a clinical sign that may indicate ascites, the presence of a fluid buildup in the abdomen. It can be identified in a physical examination where a care provider taps the abdomen to listen for changes in resonance. This test is not always effective, as it can sometimes yield a false positive or may not work as well in patients with significant fat deposits or only a small amount of fluid present. The examination can still be useful, as it may provide information about the patient’s condition and specific health concerns, especially in combination with other testing.
In an examination for shifting dullness, the patient starts lying face up in a warm, comfortable room, draped to expose the abdomen. The care provider gently taps the abdomen, listening for a resonant sound. As the care provider’s hands move to the edges, the sound may start to seem dull. For reference, people can leave their hands in place at the site of the change, or draw a line with an erasable marker.
Next, the patient is asked to change position, lying on one side of the body. The care provider waits to allow any fluid in the abdomen to shift, which takes approximately one minute. Then, the percussion can be repeated. On repetition, the dull sounds should move, indicating that there is fluid in the peritoneal cavity, and it is shifting with movement. As the test is performed, the care provider may note the extent of the shifting dullness.
Once a care provider determines that shifting dullness is present, there are several options to consider. One is more diagnostic testing to find out more about the nature of the situation and rule out false positives. The examination may also be used in an assessment of response to treatment, in which case it may be an indicator that a treatment is not working. Care providers can also recommend specific treatments to start addressing the ascites, such as managing an underlying health condition more effectively to see if this resolves the fluid buildup.
Ultrasound imaging can confirm suspicions about fluid in the abdomen, and may also be used to collect a sample for examination. Other warning signs of ascites may include a swelling in the abdomen, a feeling of fullness and tension, or a ripple effect. Patients with shifting dullness may have it for a number of reasons; liver failure is a common cause.