Part 60 (1/2)

Under this heading may be considered manipulations requiring special technical knowledge and skill: (1) Catheterization; (2) pa.s.sing of bougies; and (3) was.h.i.+ng out the tympanic cavity through the Eustachian tube.

CATHETERIZATION OF THE EUSTACHIAN TUBE.

=Indications.= (i) _As a means of diagnosis_ in order to determine (_a_) the amount and character of the obstruction within the Eustachian tube; (_b_) the condition of the mucous membrane and whether any exudation is present within the middle ear.

(ii) _For the purpose of treatment._ (_a_) In order to instil medicated drops or vapours into the Eustachian tube and tympanic cavity; (_b_) as a preliminary measure to the pa.s.sage of bougies into the Eustachian tube or to was.h.i.+ng out the tympanic cavity through the Eustachian tube.

(iii) _Catheterization is preferable to Politzer's method_ if only one ear is affected. Politzer's method, on the other hand, is preferable to catheterization (_a_) in small children; (_b_) in the case of slight middle-ear catarrh if both ears are affected; (_c_) if the pa.s.sing of the catheter is very difficult and causes pain owing to nasal obstruction; (_d_) in nervous individuals who object to the catheter; (_e_) if the sudden inflation by means of Politzer's method is more effectual than by catheterization.

_Points to notice before inflation._ 1. Care must be taken that the lumen of the catheter is not obstructed, and that the compressed air bag and auscultation tube are also in working order.

2. The nose must be cleansed of all secretion; if filled with crusts or in a septic condition, inflation must be avoided.

3. The patient should be sitting. Sometimes on inflation of the ear, especially for the first time, an attack of giddiness or faintness may occur.

4. The nose should always be examined to see that the pa.s.sage is free.

If it be obstructed catheterization may be impossible, or some special manipulation will be required in order to pa.s.s the catheter through the nose.

5. In order to prevent muscular contraction of the palatal muscles, which may grip the end of the catheter and so prevent its entrance into the orifice of the Eustachian tube, the patient should be told to breathe quietly and keep the eyes open.

A short silver or plated catheter is usually used. It is 5 inches in length and curved at its extremity. To indicate the position of the point of the catheter in the post-nasal s.p.a.ce, a ring is attached to its outer and wider extremity corresponding with the concavity of the curvature of its beak (Fig. 209). The size of the catheter varies in diameter from Nos. 1 to 4 English size, that is, the same scale as used for urethral catheters. The source of compressed air used for the inflation is usually a Politzer bag having an india-rubber tube attached. At its end is a vulcanite pointed nozzle which accurately fits into the wider extremity of the catheter.

=Technique.= The patient is seated facing the surgeon, the head being supported by a prop or by an a.s.sistant. If the patient be at all sensitive, it is wiser to spray a very small quant.i.ty of a 2 or 5% solution of cocaine or eucaine into the nose, or, better still, to pa.s.s gently a probe tipped with a small pledget of cotton-wool soaked in the cocaine solution along the inferior meatus. This will effectively anaesthetize the region of the pharyngeal orifice of the Eustachian tube, which is the most sensitive part.

[Ill.u.s.tration: FIG. 209. EUSTACHIAN CATHETER.]

The surgeon stands in front of the patient. The larger extremity of the catheter is held lightly between the thumb and first finger of the right hand, its beak being turned downwards, whilst the tip of the nose is tilted up by the thumb of the left hand (Fig. 210). In introducing the catheter into the nostril, the right hand is kept low down so that the stem of the catheter is almost in a vertical position. In this way the tip pa.s.ses over the floor of the vestibule. As the catheter is gently pushed through the nose the right hand is raised so that the instrument a.s.sumes the horizontal position and pa.s.ses backwards between the septum and the inferior turbinal, its beak being kept in close contact with the floor of the nose (Fig. 211). As the beak of the catheter enters the post-nasal s.p.a.ce, it will be felt to glide over the soft palate.

With regard to the best method of introducing the beak of the catheter into the orifice of the Eustachian tube, opinions vary. Of the many methods advised only two will be given.

The first is more suitable to those who have not had much experience in using a catheter; the second is the one naturally adopted by an expert.

_The first method._ The catheter is pushed backwards until it is felt to impinge against the posterior wall of the naso-pharynx. The beak, which at this stage is directed downwards, is next rotated a quarter of a circle inwards so that it points horizontally towards the opposite side; the position is shown by the ring at its outer extremity (Fig. 212). The catheter is now gently withdrawn until the beak is felt to catch against the posterior edge of the vomer. During these procedures the stem of the catheter should rest on the floor of the nasal cavity. The manipulations are carried out with the right hand whilst the outer extremity of the catheter is kept fixed in position by means of the thumb and finger of the left hand.

[Ill.u.s.tration: FIG. 210. Pa.s.sING THE EUSTACHIAN CATHETER. Introduction of the catheter within the nostril.]

[Ill.u.s.tration: FIG. 211. Pa.s.sING THE EUSTACHIAN CATHETER. Pa.s.sage of the catheter along the floor of the nose.]

The catheter is next pushed a short distance backwards to free it from the soft palate and rotated downwards, and finally round in an outward direction until the ring points to the outer canthus of the eye on the side to be catheterized (Fig. 213).

The point of the instrument should now engage the Eustachian tube; if, however, inflation shows this not to be the case the probability is that the catheter has been pushed too far backwards and rests on its posterior lip. This can be remedied by drawing it a little further outwards.

_The second method._ The catheter, with its beak turned downwards, is pa.s.sed gently and rapidly along the inferior meatus of the nasal cavity, and at the same time rotated slightly outwards against the inferior turbinal bone. Whilst the catheter is within the nose, this outward rotation is prevented by the narrowness of the inferior meatus, but as soon as the beak of the catheter has pa.s.sed behind the level of the inferior turbinal into the free post-nasal s.p.a.ce, it will revolve outwards and upwards and in so doing will enter the Eustachian tube, which lies just behind and above the posterior end of the inferior turbinal bone.

[Ill.u.s.tration: FIG. 212. Pa.s.sING THE EUSTACHIAN CATHETER. Beak of the catheter in the post-nasal s.p.a.ce. The catheter is turned to the opposite side so that its beak impinges against the posterior border of the septum.]

[Ill.u.s.tration: FIG. 213. Pa.s.sING THE EUSTACHIAN CATHETER. Catheter in position; act of inflation.]

Provided there be no abnormal obstruction within the nose, this method is an exceedingly simple one. With the practised hand the manipulation can be carried out so smoothly and quickly that the catheter will be in position before the patient has had time to realize the fact.