Unusual dullness may be a clue to an underlying abdominal mass. A normal liver span is 6 to 12 cm in the midclavicular line. To detect an enlarged spleen, percuss the lowest interspace in the left anterior axillary line. Ask the patient to take a deep breath and repeat. A change from tympany to dullness suggests splenic enlargement.
Palpation Begin with light palpation.
At this point you are mostly looking for areas of tenderness. The most sensitive indicator of tenderness is the patient's facial expression. Voluntary or involuntary guarding may also be present. Deep Palpation Proceed to deep palpation after surveying the abdomen lightly. Try to identify abdominal masses or areas of deep tenderness.