Tidal percussion is a clinical percussion technique used to detect early splenomegaly by observing changes in percussion note during respiration.
Site
Over Traube's space. Typically along the left mid-axillary line
Boundaries of Traube’s Space
Superior: Left 6th rib
Inferior: Left costal margin
Lateral: Left anterior axillary line
This area overlies the fundus of the stomach (normally tympanic due to air). In splenomegaly, this area becomes dull → basis of tidal percussion.
Technique
Patient lies supine
Start percussion over Traube’s space (normally tympanic)
Ask patient to take a deep inspiration
Continue percussion during breathing
- Interpretation
Normal:
Remains tympanic during inspiration
Positive tidal percussion:
Tympany → dullness on inspiration
Indicates splenic enlargement (spleen descends and occupies the space)
Mechanism
During inspiration, the diaphragm descends
Enlarged spleen moves inferiorly & anteriorly
Replaces air-filled stomach → dull note
