Manual of Surgery Volume Second: Extremities—Head—Neck. Sixth Edition.

by Alexis Thomson; Alexander Miles

Discharge from the ear, or otorrhœa, is occasionally due to an eczematous condition of the skin lining the external meatus. It is then usually of a thin, watery character, and contains epithelial flakes and débris. An aural discharge is, however, most commonly of middle-ear origin. It may be muco-purulent and stringy, or purulent and of thicker consistence. A peculiar, offensive odour is characteristic of chronic middle-ear suppuration. The surgeon should smell the speculum in suspicious cases. He should never accept the patient's statement as regards the absence of discharge, but should satisfy himself by inspection and by the introduction of a cotton-wool wick.

The Hearing Tests.—In testing the hearing, a definite routine method should be adopted, the watch, whisper, voice, and tuning-fork tests being systematically employed. Although the patient only complains of one ear, both must be examined. Each ear should be tested separately, and the patient should be so placed that he cannot see the lips of the examiner. While one ear is being tested, the other should be closed with the finger, and each test should be commenced outside the probable normal range of hearing. All the results should be written down at once, and the date of the test recorded, as this is essential for following the progress of the case.

Tuning-fork Tests.—To differentiate between deafness due to a lesion in the sound-conducting apparatus and that due to labyrinthine causes, it is necessary to enter into a little more detail. The tone produced by a vibrating tuning-fork is conducted to the nerve terminations in the labyrinth both through the air column in the external meatus (air-conduction), and through the cranial bones (bone-conduction). When, in a deaf ear, the vibrations of a tuning-fork placed in contact with the mastoid process are heard better than when the fork is held opposite the meatus, the lesion is in the sound-conducting apparatus. When, on the other hand, the vibrations are heard better by air-conduction, the lesion is in the sound-perceiving apparatus. In addition to these facts, we find also that in obstructive deafness low tones tend to be lost first, while in nerve deafness the higher notes are the first to go. This may be investigated by tuning-forks of different pitch or with the aid of a Galton's whistle. Again, in middle-ear deafness, hearing may be better in a noisy place, and be improved by inflation of the tympanum; while in labyrinthine deafness, hearing may be better in a quiet room, and be rendered worse by inflation.

Inspection of the Ear.—This should be carried out by the aid of reflected light, the ear to be examined being turned away from the window, lamp, or other source of light that may be employed. A small ear reflector, either held in the hand or attached to a forehead band, and a set of aural specula are required. Before introducing the speculum, the outer ear and adjacent parts should be examined, and the presence of redness, swelling, sinuses or cicatrices over the mastoid, displacement of the auricle, or any inflammatory condition of the outer ear observed. To inspect the tympanic membrane, a medium-sized speculum held between the thumb and index finger is insinuated into the cartilaginous meatus, the auricle being at the same time pulled upwards and backwards by the middle and ring fingers, so as to straighten the canal. The tympanic membrane is then sought for and its appearance noted.

The normal membrane is concave as a whole on its meatal aspect; it occupies a doubly oblique plane, being so placed that its superior and posterior parts are nearer the eye of the examiner than the anterior and inferior parts. While varying to some extent in colour, polish, and transparency, it presents a bluish-grey appearance. The handle of the malleus traverses the membrane as a whitish-yellow ridge, which appears to pass from its upper and anterior parts downwards and backwards to a point a little below the centre. At the lower end of the handle of the malleus a bright triangular cone of light passes downwards and forwards to the periphery of the membrane. At the upper end of the handle is a white knob-like projection, the short process of the malleus. Passing forwards and backwards from this are the anterior and posterior folds. The portion of the membrane situated above the short process is known as the membrana flaccida or Shrapnell's membrane. Behind the malleus the long process of the incus may be visible through the membrane. The mobility of the membrana tympani should be tested by inflating the tympanum or by means of Siegle's pneumatic speculum.

Various departures from the normal may be observed. Atrophy of the membrane is characterised by extreme transparency of the whole disc. Circumscribed atrophic patches appear as dark transparent areas, which show considerable mobility and bulge prominently on inflation. A cicatrix in the membrane is evidence of a healed perforation, and is also transparent, but differs from an atrophic patch in being more sharply defined from the surrounding membrane. A thickened membrane presents an opaque white appearance. Calcareous or chalky patches are markedly white, and when probed are hard to the touch; they are often evidence of past suppuration. An indrawn or retracted membrane, resulting from Eustachian obstruction, is characterised by increased concavity, undue prominence of the lateral short process of the malleus and of the anterior and posterior folds, and by the handle of the malleus assuming a more horizontal position. An inflamed membrane, showing congestion of the vessels about the malleus or a general diffuse redness, is evidence of middle-ear inflammation. A yellow appearance of the lower part of the membrane, limited above by a dark line stretching across the drum-head, is indicative of sero-purulent exudation into the tympanum. The membrane may be bulged outwards into the meatus by the fluid, and thus lie nearer the observer's eye than normally. A perforation is usually single, and varies in size from a small pinhead to complete destruction of the membrane. The labyrinthine (inner) wall of the tympanum may be visible through the perforation, and is recognised by being on a deeper plane than the membrane, and by its hard bony consistence when touched with the probe. The diagnosis of a perforation associated with middle-ear discharge may be further assisted by inspection during inflation, when bubbles of air and secretion are visible. When the perforation is invisible, its existence may be inferred if a small pulsating spot of light can be recognised through the speculum. Granulations in the tympanum appear as red fleshy masses of different sizes. When large they constitute aural polypi, which are recognised by their proximity to the outer end of the meatus, their soft consistence and mobility, and the fact that the probe may be passed round them. Granulations and polypi usually indicate the presence of middle-ear suppuration.

Inflation of the Middle Ear.—Before proceeding to inflate the middle ear, the examiner should inspect the nose, naso-pharynx, and pharynx. This should be made a routine part of the examination in all cases of ear disease. As inflation is not only an aid in diagnosis, but is also of great assistance in prognosis, it is necessary that the hearing should be tested and noted before the ear is inflated. There are three methods of inflating the tympanum: Valsalva's method, Politzer's method, and by means of the Eustachian catheter.

In Valsalva's inflation the patient himself forces air into his Eustachian tubes, by holding his nose, closing his mouth, and forcibly expiring. This method of inflation has only a limited application and is of little therapeutic value.

Politzer's Method.—For this a Politzer's air-bag and an auscultating tube, one end of which is inserted into the patient's ear and the other into the ear of the examiner, are required. The nasal end of the bag should be protected with a piece of rubber tubing or be provided with a nozzle. The patient retains a small quantity of water in his mouth until directed to swallow. The nozzle of the bag is inserted into one nostril, and the other is occluded by the fingers of the surgeon. The signal to swallow is then given, and, simultaneously with the movement of the larynx during this act, the bag is sharply and forcibly compressed. Holt's modification of this method consists in directing the patient to puff out his cheeks while the lips are kept firmly closed.

Inflation through the Eustachian Catheter.—For this method, in addition to the Politzer's bag and the auscultating tube, a silver or vulcanite Eustachian catheter is required. The silver instrument has the advantage that it can be sterilised by boiling. The patient is seated facing the light, while the surgeon stands in front of him, and, having placed the auscultating tube in position, with his left thumb he tilts up the tip of the patient's nose. The beak of the catheter is now inserted into the inferior meatus, point downwards, and carried horizontally backwards along the floor of the nose until the convexity of the curve touches the posterior wall of the naso-pharynx. When the posterior pharyngeal wall is felt, the point of the instrument is rotated inwards through a quarter of a circle; the position of the point is indicated by the metal ring upon the outer end of the catheter. The finger and thumb of the left hand should now grasp the stem of the catheter just beyond the tip of the nose so as to steady it. It is now gently withdrawn until the concavity of the beak is brought against the posterior edge of the septum nasi. With the right hand the point of the instrument is then rotated downwards and outwards through a little more than half a circle, so that the point slips into the Eustachian orifice and the metal ring looks outwards and upwards towards the external canthus of the eye of the same side. While the instrument is maintained in this position by the left hand, the nozzle of the Politzer's bag is inserted into the funnel-shaped outer extremity of the catheter, and inflation is gently carried out with the least possible jerking. Before withdrawing the catheter its point must be disengaged from the Eustachian opening by turning it slightly downwards. Difficulties in introducing the catheter may arise from the presence of spines and ridges upon, and deviations of, the septum, and it may be necessary to pass the instrument under the guidance of the mirror and speculum.