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.





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