From the Guidelines
Normal abdominal percussion findings typically include a tympanic sound over the stomach and small intestine, which are gas-filled, and a dull sound over the liver, spleen, and intestines that are filled with solid or fluid contents [ 1 ]. The normal percussion sounds can be characterized as follows:
- Tympanic sound: stomach and small intestine
- Dull sound: liver, spleen, and solid or fluid-filled intestines
- Resonant sound: over the intestines with gas, but less intense than the tympanic sound.
It's essential to note that any deviation from these normal findings, such as a uniformly dull sound or a shift in the area of tympany, may indicate an underlying abdominal pathology, such as ascites, which can be detected by percussion of the flanks and testing for shifting dullness [ 1 ]. Approximately 1500 mL of fluid must be present before flank dullness is detected [ 1, 2 ].
Normal Abdominal Percussion Sounds
The presence of a full, bulging abdomen should lead to percussion of the flanks [ 1 ]. If the amount of flank dullness is greater than usual, one should test for “shifting” [ 1 ]. The fluid wave and puddle sign are not useful in detecting ascites [ 2 ].
Abnormal Abdominal Percussion Sounds
Any deviation from the normal percussion sounds may indicate an underlying abdominal pathology. A uniformly dull sound or a shift in the area of tympany may indicate ascites or other abdominal conditions [ 1 ]. It is essential to note that the physical examination for detecting ascites in the obese patient is problematic, and an abdominal ultrasound may be required to determine with certainty if fluid is present [ 1 ].
From the Research
Normal Abdominal Percussion Findings
Normal abdominal percussion findings include:
- Tympany, which is heard with percussion over the intestines 3
- Resonance, which is heard over the normal lung, but not typically over the abdomen 3
- Dullness, which is heard over solid organs such as the liver or thigh, and can also be heard over areas of tenderness or masses in the abdomen 3, 4
Factors Influencing Percussion Sounds
The percussion sound produced can be influenced by several factors, including:
- The strength of the stroke used for percussion 3
- The condition and state of the body wall 3
- The underlying organs or disease, which can cause dullness to occur at distant sites 3
Clinical Utility of Percussion
Percussion can be a useful bedside technique for detecting certain conditions, such as: