tympany, dullness, flatness and resonance are description of percussion sounds not
"the four principles of physical examination are the following:
to achieve competence in these procedures, the student must, in the words of sir william osler, 'teach the eye to see, the finger to feel, and the ear to hear.' the ability to coordinate all this sensory input is learned with time and practice. . .
. . .percussion relates to the tactile sensation and sound produced when a sharp blow is struck to an area being examined. this provides valuable information about the structure of the underlying organ or tissue. the difference in the sensation in comparison with normal may be related to fluid in an otherwise nonfluid-containing area. collapse of a lung will change the percussion note, as will a solid mass in the abdomen. percussion that produces a dull ntoe in the midline of the lower abdomen in a man probably represents a distended urinary bladder."
(page 85-87, textbook of physical diagnosis: history and examination
, 3rd edition, by mark h. swartz, m.d.)
from page 15 of expert 10-minute physical examinations
by mosby-year book, inc., 1997. . ."percussion involves tapping or striking the patient's skin surface with your fingers or hands to elicit sounds, evaluate reflexes, uncover abnormal masses, and detect pain or tenderness. the tapping produces an audible vibration that helps to reveal the location, size, and density of the underlying structure. the three basic percussion techniques are direct, indirect, and blunt percussion.
because the body's organs, structures, and cavities differ in density, they produce sounds that differ in loudness, pitch, and duration. percussion sounds are classified as dull, flat, tympanic, resonant, or hyperresonant, and will vary depending on what part of the body or which organ you're percussing. what follows is a description of each percussion sound and where you can expect to hear it.
- tympany, a high-pitched, drum-like sound, is usually heard over the stomach
- resonance, a low-pitched, hollow sound, is usually heard over normal lung tissue.
- hyperresonance, a loud, booming sound, is usually heard over a hyperinflated lung, as in patients with emphysema.
- dullness, a soft, high-pitched, thudlike sound, can generally be heard over dense organs, such as the liver.
- flatness, a soft, high-pitched sound, is generally heard over bones, muscles, and tumors."
(from page 16)
to perform direct percussion, tap directly on the patient's skin using short, sharp strokes of the fingertip of your dominant hand. make sure the tapping movement originates from your wrist, not your elbow. after tapping, immediately lift your wrist from the skin surface so you don't muffle the sound. although you can use this technique on any part of the body, direct percussion is best for percussing the paranasal sinuses.
in this technique, used for most parts on the body, your nondominant hand serves as the striking surface. place the middle finger of your nondominant hand firmly against the patient's skin surface; keep the other fingers of that hand fanned out slightly above the skin surface. be sure to place only the pad
of your finger against the skin. then, with your dominant hand, strike the middle finger of your nondominant hand above or below the interphalangeal joint of your finger. avoid striking directly on the joint because this can affect the sounds produced.
to perform blunt percussion, either strike the ulnar surface of your fist against the patient's skin surface or place your nondominant hand over the area and use it as a striking surface for your fist. blunt percussion is useful for detecting pain or inflammation.
before using this technique on a patient for the first time, practice it until you've learned to apply just enough force to elicit tenderness without hurting the patient."
a previous thread about percussion of the abdomen and the sounds heard is posted here for you to read. i posted a reply on the difference between dull and flat tones.
"auscultation involves listening to sounds produced by internal body organs. this technique furnishes information about an organ's pathophysiology. the examiner is urged to learn as much as possible from the other techniques before using the stethoscope. this instrument should corroborate the signs that were suggested by the other techniques [inspection, palpation, and percussion]. auscultation should not be used alone to examine the heart, chest, and abdomen. this technique should be used together with inspection, percussion, and palpation." (page 87, textbook of physical diagnosis: history and examination
, 3rd edition, by mark h. swartz, m.d.)