Poor Eustachian tube function is particularly common in small children (aged
1-3
years) who do not yet have Eustachian tubes long enough orClinical Manual of Otolaryngology
oriented at the correct angle to protect their middle ears. Antimicrobial therapy commonly will sterilize the middle ear but leave a persistent serous exudate called serous otitis media. This may consolidate into a thick substance filling the middle ear, giving the term 'glue ear'. This condition can also occur in children and adults
de
novo that is not preceded by acute otitismedia. Serous otitis media is recognized by pneumatic otoscopy. The tympanic membrane is a gray or amber color, may have air bubbles or an air-fluid level behind it and because of the negative pressure is retracted and draped about the middle ear ossicles. Pneumomassage will reveal a drum that either does not move at all or has reverse movement, will lateralize with negative pressure. Older patients complain of hearing loss. Tympanometry reveals a negative pressure and tuning forks and audiometry indicate a conductive hearing loss. The diagnosis is usually made clinically. Audiologic testing is ordered only for difficult cases or to document the degree of hearing loss in patients with chronic cases.
To treat serous otitis media properly, the cause should be understood and treated. Poor Eustachian tube function is more common in children, but is also found in adults. Eustachian tube dysfunction is a term used when no other diagnosis can be made.
Many conditions may precede serous otitis media. Upper respiratory tract allergy often manifests as a chronic stuffy, runny nose. The same allergic process affects the Eustachian tube and the middle ear. Allergy treatment with antihistamine decongestants, nasal steroids or allergy testing and desensitization are indicated. Thick residual fluid from otitis media is another common prelude to serous otitis media. Examination looks for nasopharyngeal obstruction. The adenoids often obstruct the Eustachian tube orifice in children. Tumors can cause obstruction in older children and adults. Angiofibroma is the most common nasopharyngeal tumor in pubertal males. Nasal polyps can obstruct the nasopharynx at any age. An older male or female patient must be examined for a nasopharyngeal carcinoma; unilateral serous otitis media in an adult should be considered cancer until proven otherwise. All children with cleft palate have poor Eustachian tube function because of their palatal defect. Barotrauma sustained while flying or diving can also cause serous otitis media.
The nasopharynx should be examined with a transnasal flexible endoscope.
In adults and cooperative children endoscopic examination of the nasopharynx may be performed through the nose. The nasopharynx can be seen in sagittal view on soft tissue lateral X-rays (easily obtained in children) or computed tomography (CT) scans. The CT scan is used to evaluate tumors in children
and adults. Finally, if needed to rule out tumor, the nasopharynx can be examined under general anesthesia. This is most often done when there is suspicion of a tumor and a biopsy will be needed.
In adults, the nasopharynx is best examined endoscopically. Flexible and rigid endoscopes can easily be used in the clinic setting under topical anesthesia.
Treatment
The treatment for serous otitis media is a combination of scientific rationale and empiric therapy. Identified predisposing causes are treated directly (allergies, upper respiratory tract infection (RTI) and so forth). Otherwise, the following therapeutic regimen is recommended. Simple observation for
2
weeks will often result in spontaneous resolution of effusion. If effusion persists, a decongestant is prescribed. Sudafed® and Entex® are common prescriptions. Antihistamines are not prescribed as they tend to thicken secretions and impair mucociliary clearance and may impede drainage of the effusion via the Eustachian tube. If after 2 weeks of decongestant use the effusion persists, oral antibiotics (amoxicil]jn) in a dose appropriate to weight is added for10
days. The rationale for antibiotic treatment is the presence of bacteria in about30%
of cultured, clinically noninfected effusions.If the effusion persists, the antibiotic is changed and the decongestant continued. Occasionally, multiple different antibiotic courses may be necessary to clear an effusion. If effusion persists after three courses of antibiotics, myringotomy is indicated. At this point, specialty consultation with a head and neck surgeon is prudent. The specialist may try other medicines, simply observe the patient for
3-6
months or if the drum is severely retracted or if a significant conductive hearing loss exists, recommend myringotomy (tympanostomy) and middle ear ventilation tubes. Normally, this can be done under local anesthesia in adults or with a mask general anesthesia in children. Using a binocular microscope, a small incision is made in the anteroinferior quadrant of the tympanic membrane and a small flanged Silas tic tube is inserted(Figure 2.1).
This allows fluids to drain and air to enter. Normally the tube is extruded within a year, but if not, it can be easily removed. Patients, including young children, may swim and bathe with custom-fitted ear molds. Perforations requiring surgical closure occur in about1%
of patients following the extrusion of the ventilating tube.If the surgeon believes the adenoids or tonsils, or both, play a significant role in a patient's disease, they can be removed at the same time as myringotomy. However, performing these procedures raises the morbidity
Clinical Manual of Otolaryngology
Figure 2.1: Middle ear ventilation tubes, called M & T's or PE tubes, are placed through the tympanic membrane and act as an artificial Eustachian tube
and mortality rates and the cost of the surgery. Nonetheless, these procedures are often indicated to prevent further otologic complications.