Category: Professional Posters
Purpose: Aminoglycoside antibiotics are essential for the treatment of non-tuberculous mycobacteria and Pseudomonas aeruginosa lung infections in cystic fibrosis (CF). Potential nephrotoxicity and ototoxicity make appropriate monitoring critical. The 2017 Cystic Fibrosis Foundation Patient Registry (CFFPR) reports a prevalence of hearing loss of 1.3% among pediatric patients and 2.2% overall. The National Institute on Deafness and Other Communication Disorders reports an incidence of 13% among Americans aged > 12 years. A standardized aminoglycoside induced ototoxicity monitoring algorithm (AIOA) was implemented in 2017 at Children’s Mercy Kansas City (CMKC) to assess CF patients treated with intravenous and/or inhaled aminoglycosides.
Methods: The CMKC AIOA implementation process included a review of published literature, survey of CF providers, retrospective chart review, and observational cohort analysis. The algorithm 1) serves as a reference for clinicians, 2) provides specific monitoring instructions, and 3) identifies high risk patients. A team including a nurse practitioner (Cystic Fibrosis Center Coordinator) and pharmacist are responsible for monitoring adherence to the algorithm including 1) identification of new monitoring patients during pre-clinic huddles and hospitalizations, 2) review of monthly aminoglycoside prescriptions, and 3) inpatient intravenous aminoglycoside order review.
Results: Prior to implementation of the AIOA, 12 of 50 patients (24%) treated with intravenous aminoglycosides had an audiogram. In the 24 months after implementation, 43 of 44 patients (98%) treated with intravenous aminoglycosides had an audiogram; of these, 27 (63%) were abnormal. The identified hearing abnormalities included 12 patients with distortion product otoacoustic emissions (DPOAE) abnormalities and 15 patients with varying degrees of high frequency hearing loss. Prior to development of a standard process, 18 of 70 patients (26%) that received at least two courses of inhaled aminoglycosides had an audiogram. Post implementation, 19 of 33 patients (58%) receiving inhaled aminoglycosides had an audiogram per the AIOA. Among these, 10 (53%) were abnormal. In the 24 months following implementation, 30 patients had two or more audiograms. Among these 13 had unchanged audiograms; eight remained normal, three continued to have DPOAE abnormalities, and two had the same degree of high frequency hearing loss. Fourteen patients had clinically significant changes, including four that developed DPOAE abnormalities and 10 with significant ototoxic changes as defined by American Speech Language Hearing Association criteria. Interventions based on audiogram data included referral to otolaryngology and modifications to pulmonary exacerbation treatment regimens.
Conclusion: Implementation of an AIOA increased the frequency of audiogram screening among CF patients treated with intravenous and inhaled aminoglycosides. The prevalence of hearing abnormalities among people with CF identified at CMKC is higher than that reported by the CFFPR and that of the general US population. This discrepancy may be secondary to aminoglycoside usage specific to our center or lack of audiogram testing nationally. The frequent use of aminoglycosides among CF patients and the high probability of aminoglycoside induced hearing loss suggest an urgent need to establish an AIOA nationally.