Intravesical gentamicin instillation for the treatment and prevention of urinary tract infections in complex paediatric urology patients: evidence for safety and efficacy

Abstract

Background: Little has been reported to date on the instillation of antimicrobials directly into the bladder in children. Children with complex urinary tract anomalies struggle frequently with recurrent urinary tract infections (UTI), with frequent emergence of antibiotic resistance. Gentamicin bladder instillation to treat and prevent UTI was described in children since 2006.

Objective: We adopted gentamicin bladder instillation in 2016 and evaluate herein our intermediate-term experience with it.

Study design and methods: This study is a retrospective review of a prospectively initiated database and a clinical audit of our practice. The gentamicin bladder instillation was employed in 24 cases. A treatment regime was initiated for symptomatic documented UTI when resistance patterns precluded an oral alternative (14 cases), avoiding hospitalisation for parenteral antibiotics. A prophylaxis regime (19 cases-including 9 of the 14 who received an initial treatment regime) followed at least one breakthrough UTI while receiving oral prophylactic antibiotics. Two instillation volumes (8 mg gentamicin in 20 mL 0.9% NaCl or 20 mg gentamicin in 50 mL 0.9% NaCl) were used to suit different bladder capacities. The irrigation is given twice a day for 7 days in the treatment regime or once a day, every other day, in the prophylactic regime. Gentamicin serum levels (all cases) and audiology/audiometry testing (17/24 cases) were checked to assess the safety of this method.

Results: The median age when either the treatment course or prophylaxis regime was started was 3.8 years. The treatment regime was 86% successful (12/14) to suppress an acute UTI. The mean duration of prophylaxis was 252 days (median: 256 days). The percentage of patients on the prophylactic regime who had no breakthrough UTI was 58%. No serum gentamicin was detectable secondary to the intravesical instillation. No attributable cases of sensorineural hearing loss were detected. Gentamicin resistance emerged in one case (4.16%).

Discussion: Intravesical administration was feasible via various routes for a spectrum of complex lower urinary tract abnormalities (see Summary Figure). Concerns regarding systemic absorption, nephrotoxicity or ototoxicity were investigated and safety ensured. Limitations include being a small series of non-identical pathologies, albeit categorically similar and being a single-arm study, however, statistical significance was proven descriptively and analytically.

Conclusion: In selected cases and with the appropriate specialist support and logistics, intravesical gentamicin instillation is well-tolerated and safe to treat and/or prevent urinary tract infections in pateints with complex bladder conditions and lower urinary tract pathologies.

Keywords: Bladder irrigation; Bladder washouts; Clean intermittent catheterization; Intravesical instillations; Lower urinary tract dysfunction (LUTD); Urinary tract infection.