en from the
trachea are of aid but are not infallible. In doubtful cases, the
administration of diphtheria antitoxin is a wise precaution pending
the establishment of a definite diagnosis. The pseudomembrane
sometimes present in influenzal tracheobronchitis is thinner and less
pulpy than that of the earlier stages of diphtheria. The casts of the
later stages do not occur in influenzal tracheobronchitis
(Bibliography I, p. 480).

_Edematous Tracheobronchitis_.--This is chiefly observed in children.
The most frequently encountered form is the epidemic disease to which
the name "Influenza" has been given (q.v. supra). The only noticeable
difference between the epidemic and the sporadic cases is in the more
general susceptibility to the infective agent, which gives the
influenzal form an appearance of being more virulently infective.
Possibly the sporadic form is simply the attack of children not
immunized by a previous attack during an epidemic.

There is another form of edematous tracheobronchitis often of great
severity and grave prognosis, that results from the aspiration of
irritating liquids or vapors, or of certain organic substances such as
peanut kernels, watermelon seeds, etcetera. Tracheotomy should be done
if marked dyspnea be present. Secretions can then be easily removed
and medication in the form of oily solutions be instilled at will into
the trachea. In the Bronchoscopic Clinic many children have been kept
alive for days, and their lives finally saved by aspiration of thick,
tough, sometimes clotted and crusted secretions, with the aspirating
tube (Fig. 10). It is better in these cases not to pass the
bronchoscope repeatedly. If, however, evidences of obstruction remain,
after aspiration, it is necessary to see the nature of the obstruction
and relieve it by removal, dilatation, or bronchial intubation as the
case may require. It is all a matter of "plumbing" i.e., clearing out
the "pipes," and maintaining a patulous airway.

_Tracheobronchial Diphtheria_.--Urgent dyspnea in diphtheria when no
membrane and but slight lessening of the laryngeal airway is seen,
calls for bronchoscopy. Many lives have been saved by the
bronchoscopic removal of membrane obstructing the trachea or bronchi.
In the early stages, pulpy masses looking like "mother" of vinegar are
very obstructive. Later casts of membrane may simulate foreign bodies.
The local application of diphtheria antitoxin to the trachea and
bronchi has als