分泌性中耳炎课件_17

Secretory Otitis Media (SOM) #Definition: Secretory otitis media(SOM) is the nonsuppurative otitis media which characteristics are noninfected fluid in meddle ear and conductive hearing loss. #various names: serous otitis media, otitis media catarrh, middle ear effusion, and if the fluid is very sticky, called“glue ear“. #Acute otitis media (AOM) : an inflammation of the middle ear that presents with a rapid onset of signs and symptoms, such as pain, fever, irritability, anorexia, or vomiting. #Chronic otitis media: middle ear fluid that has been present for three months or longer. Classification #Changes in the middle ear in the early stages of acute suppurative otitis media are similar to those in secretory otitis media. #Some cases of secretory otitis media will go on to bacterial infection and suppuration. #otitic barotrauma. In addition Etiology and Pathology Accumulation of serous fluid in the middle ear is commonly seen with acute viral upper respiratory infection, more frequently in children than in adults. Secondary bacterial infection frequently develops. fluid 1. Obstruction of the eustachian tube appears to be the most important antecedent event associated with SOM. obstruction 2. Virus : infection in the nasopharynx with subsequent inflammation of the orifice and mucosa of the eustachian tube . 3. Bacteria : Four bacteria, ie, Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pyogenes, are responsible for the preponderance of episodes of SOM in persons older than 6 weeks. 4. Immunological activity may play a significant role in the frequency of SOM and its outcome. Clinical Features Symptoms: 1.hearing lose: A sensation of ear blockage is present. The patients own voice may sound louder to him. 2. pain: There may be discomfort or pain in the ear. 3. tinnitus: It may be low frequency sound and can be change with the head position. On Examination. The signs observed are those due to acute upper respiratory infection: fever, injected pharynx, and discharge from the nose. The ear canal is normal. The earliest change Eardrum is retracted toward the middle ear: The anterior and posterior malleolar folds and the short process and handle of the malleus become very prominent. Similarly the cone of light may appear more prominent. The mobility of the tympanic membrane may be reduced when examined with a Siegles speculum. In the next stage Increased vascularity of the tympanic membrane: That making it appear injected. Following this there is edema and a collection of fluid. Bubbles may be seen in the middle ear, usually when the eustachian tube is not completely blocked. In the absence of any superimposed bacterial infection, the fluid is serous and may appear straw colored. Increased accumulation of fluid in the middle ear may push the tympanic membrane out, producing the appearance of a full or bulging tympanic membrane. Normal Eardrum The eardrum is retracted toward the middle ear Accumulation of fluid in the middle ear The sight of eardrum with AOM The sight of eardrum with AOM fluid in the middle ear Bubbles appeared in middle ear fluid fluid in the middle ear The sight of eardrum with AOM Tuning fork tests will show a conductive hearing loss in the affected side. Audiometry: All children with AOM have conductive hearing loss associated with the middle ear effusion. Acoustic immittance measurement (Tympanometry): show B or C curve. Audiometry for pretreatment and posttreatment pretreatmentposttreatment Audiometry for pretreatment and posttreatment pretreatmentposttreatment A curve B curveC curve Impedance audiometry Treatment of Serous Otitis Media 1.Analgesics and antipyretics: for pain and fever are required for symptomatic treatment. 2.Systemic and local decongestants : nose drops containing ephedrine hydrochloride are available. A 1% solution for adults and a 0.5% solution for children . Systemic decongestants , for a period of one week; if fluid persists, further period of two weeks. 3. The other methods of ventilating the middle ear by opening the eustachian tube, Valsalvas maneuver, politzerization, and eustachian tube catheterization, the first two may be of value; the last is a blind procedure and is not commonly used. If fluid has not cleared in three weeks following this treatment, a myringotomy should be performed. None of these procedures should be done in the presence of an upper respiratory infection because they may lead to middle ear bacterial infection by introducing bacteria from the nose and nasopharynx into the middle ear. Attention Valsalvas M