Abdominal Percussion ?

  1. Can anyone explain to me what the difference is between a "dull" and "flat" sound when percussing an abdomen? To me those two terms are interchangable. Thanks!
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    About abbythetabby

    Joined: Nov '05; Posts: 110; Likes: 5
    ED RN


  3. by   EricJRN
    I've always seen them used interchangeably. The opposite would be tympanic or hyperresonant.
  4. by   Daytonite
    i've been checking some physical assessment resources that i have to see if any of them describe dullness. what i am finding is that tympany is the most common noting in the abdomen because of the presence of gas in the stomach, small bowel and colon. it has a drum-like sound. now, to me that means it kind of has an echo quality to it. here is what mark h. swartz has to say about percussion, dullness and flatness in his textbook of physical diagnosis: history and physical examination, page 264: "percussion over a solid organ, such as the liver, produces a dull, low-amplitude, short-duration note without resonance. percussion over a structure containing air within a tissue, such as the lung, produces a resonant, higher-amplitude, lower-pitched note. percussion over a hallow air-containing structure, such as the stomach, produces a typanic, high-pitched, hollow-quality note. percussion over a large muscle mass, such as the thigh, produces a flat, high-pitched note." based on that, i would be practicing these four percussions on either myself or willing volunteers and listening closely to distinguish between the differences in the sounds each produces. he goes on to say, "normally, in the chest, dullness over the heart and resonance over the lung fields are heard and felt. as the lungs are filled with fluid and become more dense, as in pneumonia, resonance is replaced by dullness. the term hyperresonance has been applied to the percussioin note obtained from a lung of decreased density, as is found in emphysema. hyperresonance is a low-pitched, hollow-quality, sustained resonant note bordering on tympany."

    since i thought that it was important to look at percussion of the abdomen of someone with ascites, this is what i found on page 373. "while the patient is on his back [an] area of tympany is present above the area of dullness. this is due to gas in the bowel that is floating on top of the ascites [fluid]. the patient is then asked to turn on the side, and the examiner again determines the borders of the percussion notes. if ascites is present, dullness will 'shift' to the more dependent position; the area around the umbilicus that was initially tympanic will become dull." i added the color and bold-facing.

    you gotta feel like you're in music class after reading that! anyway, i'd be on the lookout for patients with ascites to examine and percuss.

    now, after all that :stone , this is what it says on page 15 of expert 10-minute physical examinations by mosby published in 1997
    • typany, a high-pitched, drum-like 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.
    if you read that all over about 5 times it starts to make some rational sense and tie together. you will still need to practice to teach your ear to distinguish between these different sounds that right now only have names that may not mean much to you. hope this has been a little helpful for you. happy percussing! :1luvu:
  5. by   EricJRN
    I knew I should not have weighed in on this question. Don't do much percussing on our premies, and every time I percuss on the ambulance, it sounds pretty much like the hum of a diesel engine.
  6. by   abbythetabby
    Wowza, Daytonite! Thanks so much for the info. I missed a question on an exam, and if I can find a resource that backs up my choice, I get the points. The question had to do with bowel obstruction and whether the "flat" sound was caused by fluid trapped in the intestine or the presence of a mass in the bowel. According to your info, it would be the mass. Correct?
  7. by   Daytonite
    Oh, so that is what prompted your question. Sounds like you might be right. Here's the complete citations for the references I used with regard to the flat and dull sounds:

    Textbook of Physical Diagnosis: History and Examination, Third Edition. Mark H. Swartz, M.D. W.B. Saunders Company: Philadelphia. 1998. The ISBN # is 0-7216-7514-X

    Expert 10-Minute Physical Examinations. Edited by Catherine E. Harold and John Harvey. Mosby-Year Book, Inc.: st. Louis. 1997. The ISBN # is 0-8151-2039-7

    If you have to show the actual source and you can't find these books in a library, I'll guess you'll have to give me an address (in a PM, not on a forum post) so I can xerox and mail copies of the pages from these books to you.
  8. by   abbythetabby
    A very belated thanks, Daytonite. My instructor was willing to give me the points for the question, but I didn't need them. However, I was able to share them with a classmate, who passed the class by a half a point thanks to your help. She had a lot of personal problems this semester, but she is going to be a great nurse. Thanks so much for helping us!
  9. by   RN BSN 2009
    wow this really saved the day