, elevated and extended. The first assistant, in
this case, sits on a stool to the right of the patient's head, his
left foot resting on a box about 14 inches in height, the left knee
supporting the assistant's left hand, which being placed under the
occiput of the patient maintains elevation and extension. The right
arm of the assistant passes under the neck of the patient, the bite
block being carried on the middle finger of the right hand and
inserted into the left side of the patient's mouth. The right hand
also prevents rotation of the head (Fig. 51). As the bronchoscope or
esophagoscope is further inserted, the head must be placed so that the
tube corresponds to the axis of the lumen of the passage to be
examined. If the left bronchus is being explored, the head must be
brought strongly to the right. If the right middle lobe bronchus is
being searched, the head would require some left lateral deflection
and a considerable degree of lowering, for this bronchus, as before
mentioned, extends anteriorly. During esophagoscopy when the level of
the heart is reached, the head and upper thorax must be strongly
depressed below the plane of the table in order to follow the axis of
the lumen of the ventrally turning esophagus; at the same time the
head must be brought somewhat to the right, since the esophagus in
this region deviates strongly to the left.

[FIG. 51.--Position of patient and assistant for introduction of the
bronchoscope and esophagoscope. The middle of the scapulae rest on the
edge of the table; the head and shoulders, free to move, are supported
by the assistant, whose right arm passes under the neck; the right
middle finger inserts the bite block into the left side of the mouth.
The left hand, resting on the left knee maintains the desired degree
of elevation, extension and lateral deflection required by the
operator. The patient's vertex should be 10 cm. higher than the level
of the top of the table. This is the Boyce position, which has never
been improved upon for bronchoscopy and esophagoscopy.]

[FIG. 52.--Schema of position for endoscopy.
A. Normal recumbency on the table with pillow supporting the head.
The larynx can be directly examined in this position, but a better
position is obtainable.
B. Head is raised to proper position with head flexed. Muscles of
front of neck are relaxed and exposure of larynx thus rendered easier;
but, for most endoscopic work, a certain amount of extension is
de