Otitis media in children : detection of effusion and influence on hearing

This study was undertaken to improve the diagnosis of otitis media and to investigate possible hearing loss caused by middle ear effusion (MEE) in small children. Temporal development of AOM was assessed from 250 episodes in 184 children. Sixty-three per cent of cases of AOM occurred during the first week after the onset of URI, peaking on days 2 to 5. The onset of AOM in children with a history of recurrent episodes of AOM did not differ from that in those who had experienced only a few episodes of AOM. No individual tendency was noticed among children suffering more than one AOM episode during follow-up. Studies on symptomatology and the temporal development of acute otitis media (AOM) during upper respiratory tract infection (URI) were based on three-month follow-up of 857 children. Symptoms of URI only were compared with symptoms of URI complicated by AOM in the same child in 138 children. The most important symptom associated with AOM was earache, with a relative risk of 21.3. Sore throat, night restlessness and fever at days 3-6 were also significantly associated with AOM, with relative risks of 3.2, 2.6 and 1.8, respectively. In 44 children under two years of age, earache, conjunctival symptoms and cloudy rhinitis were significantly associated with AOM. The accuracy of minitympanometry in detecting MEE was evaluated in 162 children. The finding was compared with the amount of effusion found in myringotomy. Minitympanometry proved to be an accurate method to detect MEE in young children, the sensitivity and specificity values being 79 % and 93 % in cooperative children but it had no value in non-cooperative children. Minitympanometric examination could be performed successfully with good cooperation in 87 % of a total of 206 children in paediatric outpatient clinic. Impaired mobility of the tympanic membrane (TM) was the best sign of MEE in pneumatic otoscopy of 76 children, with sensitivity and specificity values of 75 % and 90 %, respectively. The influence of nitrous oxide (N2O) on MEE was tested by weighting the effusion found in myringotomy during general anaesthesia with and without N2O in 39 and 37 children, respectively. The mean weight of the effusion in the oxygen-air group did not differ from the weight in the N2O group, and thus peroperative findings in myringotomy are reliable. To assess the influence of the quantity and quality of MEE on hearing in small children, transient evoked otoacoustic emission (TEOAE) was performed under general anaesthesia before myringotomy in 185 ears of 102 children. Reduced TEOAEs indicating hearing loss were found in 83 % of the ears with mucoid effusion and in 56 % of the ears with non-mucoid effusion, the difference being statistically significant (p<0.01). A significant negative correlation between the reproducibility of TEOAE responses and the amount of effusion was found (Spearman rank correlation coefficient r=-0.589, p<0.001). Findings in minitympanometry correlated with the responses of TEOAE. Although parents are able to predict AOM quite reliably, various symptoms and the duration of URI seems to be of little value in helping the diagnosis of AOM. Detection of effusion in OM may be improven by minitympanometry in cooperative children. Any kind of effusion may cause hearing loss in small children, which must be considered when treating OM.