"adventitious", medical usage

[Mark Mandel]

Stedman's online provides, for "adventitious":

>>>
   1. Arising from an external source or occurring in an unusual place
or manner. See Also: extrinsic
   2. Occurring accidentally or spontaneously, as opposed to natural
causes or hereditary.
   3. Syn: adventitial
<<<

My sister the MT sends two definitions for "adventitious" in the
specific context of breath sounds:

>From Stedman's (http://www.stedmans.com/section.cfm/45)

>>>
adventitious breath sounds: sounds heard by auscultation of abnormal
lungs. See Also: crackle, crepitation, crunch, rale, rhonchus, rub,
wheeze.
<<<

from http://www.rnceus.com/resp/respabn.html , a training site for
RNs. In the first bulleted list, the sub-bullet beginning "For
example" describes sounds that are adventitious in the OED's sense 3,
but these seem here to be a separate class from those described just
below it as "adventitious":

>>>>
Abnormal Breath Sounds

Abnormal breath sounds include:

    * the absence of sound and/or
    * the presence of "normal" sounds in areas where they are normally
not heard.
          o For example, bronchial (loud & tubular) breath sounds are
abnormal in peripheral areas where only vesicular (soft & rustling)
sounds should be heard. When bronchial sounds are heard in areas
distant from where they normally occur, the patient may have
consolidation (as occurs with pneumonia) or compression of the lung.
These conditions cause the lung tissue to be dense. The dense tissue
transmits sound from the lung bronchi much more efficiently than
through the air-filled alveoli of the normal lung.

The term “adventitious” breath sounds refers to extra or additional
sounds that are heard over normal breath sounds. Sources differ as to
the classification and nomenclature of these sounds, but most
examiners commonly use the following terms to describe adventitious
breath sounds.

    * crackles (or rales)
    * wheezes (or rhonchi)
    * pleural friction rubs
    * stridor

Detection of adventitious sounds is an important part of the
respiratory examination, often leading to diagnosis of cardiac and
pulmonary conditions.
<<<<

m a m

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