Technic For General Anesthesia
Categories:
ANESTHESIA FOR PERORAL ENDOSCOPY
Sources:
A Manual Of Peroral Endoscopy And Laryngeal Surgery
For esophagoscopy and gastroscopy,
if general anesthesia is desired, ether may be started by the usual
method and continued by dropping upon folded gauze laid over the mouth
after the tube is introduced. Endo-tracheal administration of ether
is, however, far safer than peroral administration, for it overcomes
the danger of respiratory arrest from pressure of the esophagoscope,
foreign body, or both, on the trachea. Chl
roform should not be used
for esophagoscopy or gastroscopy because of its depressant action on
the respiratory center.
For bronchoscopy, ether or chloroform may be started in the usual way
and continued by insufflating through the branch tube of the
bronchoscope by means of the apparatus shown in Fig. 13.
In case of paralysis of the larynx, even if only monolateral, a
general anesthetic if needed should be given by intratracheal
insufflation. If the apparatus for this is not available the patient
should be tracheotomized. Hence, every adult patient should be
examined with a throat mirror before general anesthesia for any
purpose, and the necessity becomes doubly imperative before goiter
operations. A number of fatalities have occurred from neglect of this
precaution.
Anesthetizing a tracheotomized patient is free from danger so long as
the cannula is kept free from secretion. Ether is dropped on gauze
laid over the tracheotomic cannula and the anesthesia watched in the
usual manner. If the laryngeal stenosis is not complete,
ether-saturated gauze is to be placed over the mouth as well as over
the tracheotomy tube.
Endo-tracheal anesthesia is by far the safest way for the
administration of ether for any purpose. By means of the silk-woven
catheter introduced into the trachea, ether-laden air from an
insufflation apparatus is piped down to the lungs continuously, and
the strong return-flow prevents blood and secretions from entering the
lower air-passages. The catheter should be of a size, relative to that
of the glottic chink, to permit a free return-flow. A number 24 French
is readily accommodated by the adult larynx and lies well out of the
way along the posterior wall of the larynx. Because of the little room
occupied by the insufflation catheter this method affords ideal
anesthesia for external laryngeal operations. Operations on the nose,
accessory sinuses and the pharynx, apt to be attended by considerable
bleeding, are rendered free from the danger of aspiration pneumonia by
endotracheal anesthesia. It is the safest anesthesia for goiter
operations. Endo-tracheal anesthesia has rendered needless the
intricate negative pressure chamber formerly required for thoracic
surgery, for by proper regulation of the pressure under which the
ether ladened air is delivered, a lung may be held in any desired
degree of expansion when the pleural cavity is opened. It is indicated
in operations of the head, neck, or thorax, in which there is danger
of respiratory arrest by centric inhibition or peripheral pressure; in
operations in which there is a possibility of excessive bleeding and
aspiration of blood or secretions; and in operations where it is
desired to keep the anesthetist away from the operating field. Various
forms of apparatus for the delivery of the ether-laden vapor are
supplied by instrument makers with explicit directions as to their
mechanical management.
We are concerned here mainly with the technic of the insertion of the
intratracheal tube. The larynx should be examined with the mirror,
preferably before the day of operation, for evidence of disease, and
incidentally to determine the size of the catheter to be introduced,
though the latter can be determined after the larynx is
laryngoscopically exposed. The following list of rules for the
introduction of the catheter will be of service (see Fig. 59).