Raised ABR threshold after suction aspiration of glue from the middle ear: three case studies.

Between 1991 and 1993, 13 children (25 hearing ears) underwent recordings of the auditory brain stem response (ABR) under a general anaesthetic. The anaesthetic technique was similar for each child. Fourteen of these ears had fluid aspirated after myringotomy with insertion of grommets prior to the auditory brain stem response investigation. On subsequent hearing assessment six of these 14 ears (43 per cent) showed clear evidence of a threshold shift of 15 dB or greater. Eleven ears had either dry myringotomies or did not have a myringotomy prior to ABR and none of these showed evidence of a temporary threshold shift. Using Fisher's Exact probability test this difference is significant (p = 0.034). We feel it is important to report these observations so that unexpected high ABR thresholds following aspiration of glue are interpreted with caution.