[In chronic cases, in which the throat has become more or less accustomed to the use of instruments, intubation can be performed with greater facility and with less discomfort to the patient by the aid of the mirror than by the usual method. JOSEPH O'DWYER, Assoc. Ed., Annual, '92.] Intubation in children by this method is impracticable. The patient must be properly held before a good light. The base of the tongue is held down with a tongue-depressor, and, as the epiglottis rises to view, the point of the tube is directed into the larynx, passing immedi ately behind the epiglottis. The tube is then pressed down into position with the forefinger of the left hand as the tube is released from its introducer. As soon as the point of the tube passes over the epi glottis, the hand holding the introducer must be quickly elevated, keeping the point of the tube stationary until the turn is made, in order that the tube may pass down at an acute angle. Otherwise the tube will invariably slide over into the oesophagus. The annexed cut shows how such a misdirection can be given the tube. This method, however, is not to be preferred; but it may be employed by those who do not possess or who can not acquire the manual dexterity to per form the operation with the assistance of the tactile sense alone: i.e., unaided by the eye.
The ideal operation should be con ducted through the sense of touch en tirely. One should handle the instru ments frequently; the sliding spring of the introducer, shown in the cut, should be moved by the thumb and not by the forefinger. The extractor should be held in the manner indicated by the second figure. By frequently introducing the tube into the closed hand of another per son, holding the introducer in the right hand, detaching the tube and pressing it down with the forefinger of the left hand in the exact manner as when introduced into the larynx, slight practical experi ence can be gained. One should become so familiar with the instruments that the various steps of the operation can be car ried out, so to say, automatically.
As the extraction of the tube is even more difficult than its introduction, it is important also to practice extracting it from the closed hand of another. Intro ducing and extracting the tube from the larynx of a small dog under an anesthetic will frequently be of great help in acquir ing dexterity.
The instruments should be held lightly. Little or no force should be used, no anaesthetic is necessary, and the operation should not require longer than from five to ten seconds. It occasionally happens that when the end of the tube reaches the larynx, and before it becomes engaged, spasm of the larynx occurs. In such a case it is best, instead of using force, to simply wait a few seconds, hold ing the tube in position. The patient will then endeavor to breathe, the spasm will relax, and the tube will drop into position.
Greatest care recommended in intro duction to avoid laceration of the tissues; the tube should be removed every three days to avoid irritation from the cal careous deposits. If a tube is introduced more than twice, it is of advantage to use a rubber tube, immersing it in a solu tion of hot gelatin, containing 5 to 10 per cent. of powdered alum; a 10-per-cent.
solution of ichthyol and gelatin is also a valuable preparation. An imperfectly ; constructed tube or one which does not and should be placed upon the table within easy reach. The patient should be held upright in the lap of the nurse supported closely against the left chest with the head resting on the shoulder. The nurse should sit :in a properly fit the larynx may tend to in jury followed by stenosis. Fischer (Med. Record, Dec. 2, '99).
In performing the operation the phy sician should first select a tube appropri ate for the age of the patient, as indi cated by a scale that accompanies every set of instruments. The tube should then be threaded with silk or linen ' straight-backed chair and the patient be held firmly and not be allowed to slide down. The forearms of the child should be crossed in front and the nurse should grasp the wrists, the left wrist with the right hand and the right wrist with her left hand. The gag is then introduced in the left angle of the mouth well thread, making a loop about fourteen inches in length. The obturator fitting the tube to be used (Fig. 7) should then be screwed upon the introducer if the O'Dwyer instruments are used, and the tube attached. It is now ready for use, back between the teeth and widely opened (Fig. 13). The operator standing in front then quickly seizes the intro ducer with tube attached, hooks the loop or bridle over the little finger of the left hand, and introduces the index finger of the same hand closely followed by the tube (Fig. 14). He raises the epiglottis forward with the index finger (Fig. 9) and guides the end of the tube gently over it when, by making an abrupt turn, he will pass the tube into the larynx if he has been careful to keep in the median line; or he may pass the index finger over the epiglottis and upon the aryte noid cartilages and guide the end of the tube into the larynx.
My method is to feel for the small opening or depression just back of the epiglottis with the finger and guide the end of the tube into it. In any case the end of the tube should pass under the tip of the finger, not over it or by the side of it, but directly under it. The moment the end of the tube engages the larynx the right hand, holding the introducer, should be quickly elevated allowing the tube to pass down at right angle. Simul taneously the tube is loosened from the introducer by pressing forward the slide with the thumb. The index finger of the left hand, which has acted as guide, is placed upon the head of the tube and gently presses it down into position -as the introducer is removed. It is impor tant to bear in mind the necessity of hugging the anterior wall with the end of the tube as it is introduced. In order to do this, it should follow a gentle curve, until it has passed over the epiglottis, and remain stationary for an instant as far as downward progress is concerned, while the handle is quickly elevated. The dark line in Fig. 15 represents the curve that should be followed by the end of the tube while it is being introduced. This sud den turn constitutes one of the salient points of the operation, for if the curve be continued as indicated by the dotted line, the tube will invariably pass into the oesophagus.