Aerating the Ear

AERATING THE EAR. The ear, or the introduction of air into the tympanic cavity through the Eustachian tube, has been used in medicine since ancient times. The oldest and simplest method of aerating the ear is the so-called Valsalva experiment (see). The penetration of air into the ear (into both or into one) is accompanied by a special sensation of cracking or noise, and with a perforated tympanic membrane a whistle can be heard objectively. In modern otology, this method has only historical significance and is almost completely abandoned, since it succeeds only in cases of good patency of the Eustachian tube, and with frequent application it causes hyperemia of the mucous membranes and can worsen the course of the inflammatory process in the middle ear, in the nose, and in the pharynx. A more reliable result is given by the Politzer method (Politzer, 1863). Increased air pressure in the nasopharynx is produced by means of a rubber balloon with an olive-shaped tip; the latter is inserted into one nostril with the other closed. The method is based on the fact that during the act of swallowing and during the pronunciation of certain consonants (K) the soft palate tightly closes the nasopharynx, where, in this way, favorable conditions are created for increasing air pressure when the balloon is strongly compressed. The simultaneous opening of the mouth of the Eustachian tube during swallowing facilitates the passage of air into the middle ear. The method is easily performed, requires no special skill, and can be applied even to small children without difficulty. Disadvantages of the method include: 1) inevitable entry of air into both ears when it is necessary to aerate only one, in which case the healthy ear is aerated more easily than the diseased ear, 2) difficulty in dosing the air pressure, and 3) the brevity of the process, as a result of which the assessment of the noise occurring in the ear is little accessible. In addition, such aerating can cause headache, dizziness, noise in the ears, rupture of the tympanic membrane, entry of air into the ventricles, etc. The third, more perfect method is catheterization or the blowing of air into the ear with an ear catheter. The latter is a metal tube 15–16 cm long, bent at one end in the form of a beak and with a funnel-shaped flared end at the other for inserting the balloon tip; near this expansion a ring is fixed, indicating the direction of the beak. The catheter is introduced through the nasal cavity into the opening of the Eustachian tube. The idea of catheterization belongs to the postmaster from Versailles Guyot (Guyot, 1724), who himself introduced a tin tube into the Eustachian tube through the mouth; only Cleland in 1741 reported the introduction of a silver tube through the nose. The technique of catheterization requires experience: the catheter is held by the thumb and index finger of the right hand, introduced into the nasal opening beak down and carefully advanced along the floor of the nose until it meets the posterior wall of the pharynx; at this moment, guided by the ring, the catheter is turned inside in the direction opposite to the ear being aerated and pulled back until the curvature of the beak rests against the posterior edge of the vomer. As soon as this obstacle is felt, the catheter is turned around its axis by 180° and the beak enters the opening of the Eustachian tube; at this time the ring points toward the outer corner of the eye. With the catheter in this position, 5–10 inflations are made into the ear with a rubber balloon. The entry of air into the ear is judged by the characteristic noise heard through the otoscope, i.e., through a rubber tube about 70 cm long, one end of which is pre-inserted into the patient's ear and the other into the doctor's ear. The advantage of catheterization over other methods lies in the fact that each ear is aerated separately and the force of the inflation is precisely regulated. Difficulties in introducing the catheter occur: 1) with the closure of the lower nasal passage due to a deviated septum or spicules in it, 2) with strong irritation of the pharyngeal mucosa due to reflex elevation of the soft palate and coughing, 3) with abnormal narrowing of the Eustachian tube, 4) with tumors and scars of the nasopharynx and atresia of the choanae, 5) in children due to restlessness and resistance. Unpleasant accidents: bleeding from injury to the mucous membrane, emphysema if air is forced into the loose connective tissue of the pharynx, dizziness, fainting, rupture of the tympanic membrane. Aerating is applied both for diagnosis and for treatment. The diagnostic value is mainly reduced to determining the character of the noise heard through the otoscope, which makes it possible to judge about the narrowing or dilation of the Eustachian tube or to confirm effusion in the tympanic cavity, by the crackling noise. The therapeutic effect is always better from catheterization than from other methods, and is based on the mechanical action of the air blown into the tube and into the middle ear. From this action follow the indications and contraindications for aerating the ear. Aerating the ear is indicated in all disorders of the patency and ventilation of the Eustachian tube, in exudative inflammations of the middle ear after the acute phenomena have subsided, in disorders of the mobility of the ossicular chain for various reasons, and in adhesive processes in the middle ear. It is contraindicated in acute inflammations of the mucosa of the nose, pharynx, and ear, in all diseases of the labyrinth and the auditory nerve, in otosclerosis, and in acute infectious diseases.