ACUTE OTITIS MEDIA

ACUTE OTITIS MEDIA OTITIS MEDIA Huỳnh Khắc Cường , M.D Senior Lecturer – Otolaryngology Department University UMP at HoChiMinh City Otitis Media  Otitis media is one of the most common diagnoses among children  Nat’l Ambulatory Medical Care Surveys data indicate that the number of office visits for OM increased by more than 2-fold from 1975-1990  This survey estimated over 5.18 million episodes of AOM in 1995 at a cost of $2.98 billion Acute Otitis Media  OTITIS MEDIA = inflammation of the middle ear, is defined by the presence of fluid in the middle ear accompanied by signs or symptoms of acute illness  The peak incidence occurs in the first years of life The disease is less common in the schoolaged child, adolescents, and adults  Nevertheless, infection of the middle ear may be the cause of fever, significant pain, and impaired hearing in these age groups Definitions Acute Otitis Media with Effusion (AOME):  Suppurative – mung mủ infection of the middle ear  sudden  short  the onset duration inflamed tympanic membrane is bulging and/or opacified Definitions Chronic Otitis Media (COM)  COM with Effusion or nonsuppurative OM :  Middle ear effusion behind an intact eardrum  Persist for more than 2-3 months  Asymptomatic không triệu chứng except for hearing loss  No acute symptoms  May follow AOM Definitions Chronic Suppurative Otitis Media (CSOM):  chronic perforation of the TM  purulent discharge for >6 weeks  insidious âm thầm onset  may follow AOM Otitis Media Epidemiology  Most common bacterial infection in children and most commonly diagnosed  Half of all children will have an episode before the first birthday, and 80% before the third birthday  The most frequent reason for prescribing antibiotics Otitis Media Epidemiology  It accounts for more than 1/3 of office visits to pediatricians each year  The number of office visits continues to rise, in 1997 it reached 25.9 billion  4-5 billion dollars spent each year in direct care costs Pathogenesis The vast majority of children have no obvious defect responsible for severe and recurrent otitis media, but a small number have anatomic changes (cleft palate, cleft uvula, submucous cleft), alteration of normal physiologic defenses (patulous eustachian tube), or congenital or Otitis Media : Pneumatic Otoscopy  Used to assess the landmarks, mobility, color, transparency, vascularity and position of the tympanic membrane  Fluid levels or bubbles can be seen if membrane is translucent  Confirms middle ear effusion by assessing mobility when + or – pressure is applied  Needs an adequate seal with ear canal Acute Otitis Media Diagnosis  Identification of middle ear effusion  pneumatic otoscopy  tympanometry  acoustic  Signs reflectometry or symptoms of acute local or systemic illness OM : Short Term Complications Intratemporal : Intracranial :  mastoiditis  meningitis  labrynthitis   facial nerve paralysis lateral sinus thrombosis – nghẽn mạch  petrositis  brain abscesses  hearing loss   subperiosteal abscess sigmoid sinus thrombophlebitis OM Long Term Complications Speech and Language delay  Tympanic membrane perforation  Cholesteatoma  Tympanic membrane retraction pockets  Hearing loss  Chronic otorrhea  Cognitive impairment  Otitis Media Etiology  S Pneumoniae  H Influenzae  M Catarrhalis  Group A Strep  Staph Aureus  Negative culture/  non pathogens 32% 22% 16% 5% 2% 25% Otitis Media : Antimicrobial Resistance  S pneumoniae 30-40% penicillin resistant  H influenzae 30-40% -lactamase positive  M catarrhalis 80-90% -lactamase (+)  Levels of resistance vary with different geographic areas Resistance Patterns in the Common Bacterial Pathogens  Pneumococcus: variable resistance to penicillin is found including both high level and intermediate level resistance  H influenzae: increasing betalactamase production , up to 80% in some areas  M catarrhalis: nearly universal betalactamase production Guidelines for the use of Antibiotics in AOM Rationale for the continued use of amoxicillin :  S pneumoniae is responsible for about 40% of cases of AOM Concentrations of amoxicillin can be achieved in the middle ear fluid sufficient to sterilize all but highly resistant strains  Less than 10% of pneumococci isolated from the nasopharynx of Boston children are high level resistant (MIC’s>2 mug/ml) and treatment in about 4% of all children with acute otitis might fail if they are treated with regular doses of amoxicillin (40 mg/kg/day) Guidelines for the use of Antibiotics in AOM The recent recommendation of doubling the dose of amoxicillin to 80 mg/kg/day will achieve higher concentrations in middle ear fluid and further reduce the number of children in whom amoxicillin therapy will fail because of resistant pneumococci Guidelines for the use of Antibiotics in AOM  H influenzae and M catarrhalis are responsible for about 30 and 10% of AOM cases, respectively If 30% of H Flu and 75% of M cat are b-lactamase +, then 16% of AOM cases are caused by beta-lactamaseproducing organisms  If 50% improve spontaneously or despite betalactamase activity, then less than 10% of the failures could be anticipated to be due to failure of amoxicillin to be active against beta-lactamase-producing organisms Second Line Therapy CHOICES: – Augmentin® (adds coverage for beta-lactamase producing organisms) – Cefuroxime axetil; cefpodoxime; azithromycin; ceftriaxone IM injection To treat or not to treat ?  Previous studies have shown that the majority of cases of AOM will resolve without specific therapy  Antibiotic usage varies from 31% in the Netherlands to 98% in the US and Australia  Cockrane Abstract : review of evidencebased literature to assess the effects of antibiotherapy in AOM Cockrane Abstract : review of evidenced based literature to assess the effects of antibiotics in children with AOM  10 randomized trials comparing antimicrobial agents to placebo in children with AOM  Total of 2,202 children  Pain: – No reduction in pain at 24 hours with antibx – 28% relative reduction in pain at 2-7 days – Since ~ 80% of cases will have resolved in this time, this represents an absolute reduction of about 5% Cockrane Abstract : review of evidenced based literature to assess the effects of antibiotics in children with AOM  Other Effects: – No effect on hearing problems (as measured by tympanometry and audiometry in two studies only) – No influence on other complications or recurrences  Complications: – One case of mastoiditis occurred (in PCN treated group) What can we ? Increase the accuracy of AOM diagnosis Understand societal pressures for antibiotic prescriptions and educate parents about appropriate use of antibiotics Evaluate non-antimicrobial treatments or preventives (e.g vaccines)