An audit of hearing assessment in a regional paediatric cystic fibrosis centre

Introduction: Intravenous aminoglycoside therapy (IVA) is an established treatment for pseudomonas in CF and is associated with irreversible ototoxicity. The prevalence of ototoxicity in CF is reported as 0−6% in children. The UKCF Trust and the European Consensus Committee for Antibiotic Therapy in CF do not give guidance for screening or monitoring hearing and there is little literature available on this subject. There is a genetic predisposition to aminoglycoside ototoxicity associated with the mitochondrial gene A1555G. Since 2002 we have included hearing assessment (HA) at annual review and screened all patients for A1555G. Aim: To asses the prevalence of hearing loss in our clinic and evaluate our HA programme. Method: Retrospective case note analysis 2002–2009 of HA, gene result, IVA use and aminoglycoside blood levels. Results: Pure tone audiometry and/or distortion-product otoacoustic emissions performed on 76 patients, age 1−17 years, 49 received IVA. Severe sensorineural hearing loss for high frequency sounds (SNHL) identified in 1 patient and 4 had mild SNHL. The patient with severe SNHL had one high blood level of tobramycin recorded. No relationship between cumulative exposure and hearing loss was identified. No hearing deficit was found in patients not exposed to IVA. No patients have the A1555G mutation. Conclusion: We have adhered to our HA programme and have identified 5/76 (6.6%) patients with hearing loss all of whom have had IVA. From 2010 patients with no genetic predisposition to aminoglycoside ototoxicity and no IVA will have HA at diagnosis and at 5 and 11 years. The annual HA will continue for patients who have had intravenous aminoglycoside.