VCP 411: Medicine Section

PERCUSSION

• Percussion a physical method of examination by means of striking a part of the body, to obtain information about the condition of the contiguous tissues and particularly the deeper lying parts. The sound reflected vary in volume, pitch or tone depending on the density of the tissues. It is done for the examination of the thorax (lung and heart) also employed in diseases of the abdominal cavity, paranasal sinuses and in subcutaneous emphysema.
• Percussion is carried out for
• Assessing the sensitivity to pain and
• To set in vibration and emit audible sounds.

Different methods of percussion and their applications

• Immediate or direct percussion: done by fingers or plexor. Particular organ is struck directly. It is done by using hand or acoustic hammer over the chest.
• Mediate or indirect percussion: by instruments (plexor and pleximeter) when the finger or a pleximeter is placed over the area being struck.
• Tactile percussion & ballotment
• An interrupted firm push or stroke is applied with object for evoking motion in the underlying organ so as to make it to rebound on to the finger tips
• eg. advanced pregnancy in cattle, free fluid in the body cavity in ascites.
• Other methods: Tracheal percussion – tracheal are is percussed and the chest is auscultated.
• Tuning fork, stethoscope method – percussion and auscultation.
• Tracheal percussion combined with auscultation – In normal lung, percussion sound is indistinctly heard since it contains air and thus resulting in poor conduction of sound.
• Consolidated lung – lung sound is distinct.
• Pneumonia – sound is heard as if it originates directly beneath the chest piece of the stethoscope.

Instruments required for percussion

• Small animals: Instruments: Plexor (acoustic), Pleximeter. Hands – finger of one hand as plexor and that of the another as pleximeter
• Large animals: Pleximeter – circular, oval or winged or spatula shaped pleximeter Hammer with two heads, and pain seeking hammer.