Physical Signs Of Bronchial Foreign Body
Categories:
FOREIGN BODIES IN THE AIR AND FOOD PASSAGES
Sources:
A Manual Of Peroral Endoscopy And Laryngeal Surgery
In most cases there will be limitation of expansion on the invaded
side, even though the foreign body is of such a shape as to cause no
bronchial obstruction. It has been noted frequently in conjunction
with the presence of such objects as a common straight pin in a small
branch bronchus. This peculiar phenomenon was first noted by Thomas
McCrae in one of the author's cases and has since been abundantly
corroborated by
McCrae and others as one of the most constant physical
signs.
To understand the peculiar physical findings in these cases it is
necessary to remember that the bronchi are not tubes of constant
caliber; there occurs a dilatation during inspiration, and a
contraction of the lumen during expiration; furthermore, the lumen may
be narrowed by swollen mucosa if the foreign body be of an irritant
nature. The signs vary with the degree of obstruction of the bronchus,
and with the consequent degree of interference with aeration and
drainage of the subjacent portion of the lung. We have three definite
types which show practically constant signs in the earlier stages of
foreign body invasion.
1. Complete bronchial occlusion.
2. Obstruction complete during expiration, but allowing the passage
of air during the bronchial dilatation incident to inspiration,
constituting an expiratory valve-like obstruction.
3. Partial bronchial obstruction, allowing to-and-fro passage of
air.
1. Complete bronchial obstruction is manifested by limitation of
expansion, markedly impaired percussion note, particularly at the
base, absence of breath-sounds, and rales on the invaded side. An
atelectasis here exists; the air imprisoned in the lung is soon
absorbed, and secretions rapidly accumulate. On the free side a
compensatory emphysema is present.
2. Expiratory Valve-like Obstruction.--The obstructed side shows
marked limitation of expansion. Percussion is of a tympanitic
character. The duration of the vibrations may be shortened giving a
muffled tympany. Various grades and degrees of tympany may be noted.
Breath sounds are markedly diminished or absent. No rales are heard on
the invaded side, although rales of all types may be present on the
free side. In some cases it is possible to hear a short inspiratory
sound. Vocal resonance and fremitus are but little altered. The heart
will be found displaced somewhat to the opposite side. These signs are
explained by the passage of some air past the foreign body during
inspiration with its trapping during expiration, so that there is air
under pressure constantly maintained in the obstructed area. This type
of obstruction is most frequently observed when the foreign body is of
an organic nature such as nut kernels, beans, corn, seed, etc. The
localized swelling about the irritating foreign body completes the
expiratory obstruction. It may also be present with any foreign body
whose size and shape are such as to occlude the lumen of the bronchus
during its contracted expiratory phase. It was present in cases of
pebbles, cylindrical metallic objects, thick tough balls of secretion
etcetera. The valvular action is here produced most often by a change
in the size of the valve seat and not by a movement of the foreign
body plug. In other cases I have found at bronchoscopy, a regular
ball-valve mechanism. Pneumothorax is the only pathologic condition
associated with signs similar to those of expiratory, valve-like
bronchial obstruction by a foreign body.
3. Partial bronchial obstruction by an object such as a nail allows
air to pass to and fro with some degree of retardation, and impairs
the drainage of the subjacent lung. Limitation of expansion will be
found on the invaded side. The area below the foreign body will give
an impaired percussion note. Breath-sounds are diminished in the area
of dullness, and vocal resonance and fremitus are impaired. Rales are
of great diagnostic import; the passage of air past the foreign body
is accompanied by blowing, harsh breathing, and snoring; snapping
rales are heard usually with greatest intensity posteriorly over the
site of the foreign body (usually about the scapular angle).
A knowledge of the topographical lung anatomy, the bronchial tree, and
of endoscopic pathology* should enable the examiner of the chest to
locate very accurately a bronchial foreign body by physical signs
alone, for all the significant signs occur distal to the foreign body
lodgment.
* Jackson, Chevalier. Pathology of Foreign Bodies in the Air and Food
Passages. Mutter Lecture, 1918. Surgery, Gynecology and Obstetrics,
March, 1919. Also, by the same author, Mechanism of the Physical Signs
of Foreign Bodies in the Lungs. Proceedings of the College of
Physicians, Philadelphia, 1922.
The asthmatoid wheeze has been found by the author a valuable
confirmatory sign of bronchial foreign body. It is a wheezing heard by
placing the observer's ear at the open mouth of the patient (not at
the chest wall) during a prolonged forced expiration. Thomas McCrae
elicits this sign by placing the stethoscope bell at the patient's
open mouth. The quality of the sound is dryer than that heard in
asthma and the wheeze is clearest after all secretion has been removed
by coughing. The mechanism of production is, probably, the passage of
air by a foreign body which narrows the lumen of a large bronchus. As
the foreign body works downward the wheeze lessens. The wheeze is
often so loud as to be heard at some distance from the patient. It is
of greatest value in the diagnosis of non-roentgenopaque foreign body
but its absence in no way negates foreign body. Its presence or
absence should be recorded in every case.
Prolonged bronchial obstruction by foreign body is followed by
bronchiectasis and lung abscess usually in a lower lobe. The symptoms
may with exactitude simulate tuberculosis, but this disease should be
readily excluded by the basal, unilateral site of the lesion, absence
of tubercle bacilli in the sputum, and roentgenographic study. Chest
examination in the foreign body cases reveals limitation of expansion,
often some retraction, flat percussion note, and greatly diminished or
absent breath-sounds over the site of the pulmonary lesion. Rales vary
with the amount of secretion present. These physical signs suggest
empyema; and rib resection had been done before admission in a number
of cases only to find the pleura normal.