Aim Standard treatment for Pseudomonas aeruginosa respiratory infection in individuals with cystic fibrosis (CF) involves nebulised and intravenous aminoglycoside. Recognised complications include permanent ototoxicity even when therapeutic doses are used. 17% of all CF individuals have significant hearing impairment related to cumulative effect of aminoglycoside use. This audit cycle aims to establish whether baseline-hearing tests are recorded in hospital notes and annual review reports of children with CF. Further to establish if those exposed to intravenous aminoglycoside had hearing re-checked.
Method Recording of hearing test results were audited in March 2008 and repeated in September 2009. National and regional CF guidelines for care were used as standards for audit purposes. National and regional CF Databases did not specifically record hearing test results. Hospital notes for 30 children with CF in the local specialist paediatric clinic were checked and annual review reports examined for recorded hearing test results of all types. Audiology departmental records were also searched. Pure tone audiograms are recommended when the child is able to perform.
Results Recorded baseline-hearing tests improved from 26/30 (87%) in 2008 to 29/30 (97%) in 2009. Record of the hearing test result in the annual review report improved from 0/30 to 17/30 (57%) in 2009. Recorded hearing test results after exposure to intravenous aminoglycoside treatment improved from 14/16 (88%) to 15/16 (94%).
Conclusion There is significantly increased awareness of hearing problems after aminoglycoside use in children with CF. Audiological testing and clear recording of the results is now standard practise in the local CF clinic. Testing CF individuals for the mitochondrial DNA mutation m.1555A→G is being considered. Testing of CF children could inform the family and physician of the likelihood of high frequency hearing loss after exposure to therapeutic doses of aminoglycoside. Its use in the CF population as a screening tool would require careful debate between professionals and counselling for families prior to testing.
Acknowledgement Dr Jenny Tyrrell, Consultant Paediatrician for CF Care.