Related Experiment Video
Updated: Sep 29, 2026
Behavioral Assessment of Hearing in 2 to 4 Year-old Children: A Two-interval, Observer-based Procedure Using Conditioned Play-based Responses
Published on: January 23, 2017
A pilot case control follow-up study on hearing in children treated with tobramycin in the newborn period
Matthijs de Hoog1, G A van Zanten, L J Hoeve
1Pediatrics Intensive Care Unit, Department of Pediatrics, Erasmus University and University Hospital Rotterdam/Sophia Children's Hospital, Dr Molewaterplein 60, 3015 GJ, Rotterdam, The Netherlands. dehoog@alkg.azr.nl
Insights
This pilot study found no statistical link between neonatal tobramycin exposure and hearing loss in children, likely due to small sample size. Further research is recommended to investigate aminoglycoside ototoxicity in neonates.
Area of Science:
- Neonatal care
- Pediatric audiology
- Pharmacology
Background:
- Neonatal exposure to tobramycin, an aminoglycoside antibiotic, is a concern for potential ototoxicity.
- Assessing hearing loss in young children requires specialized audiological evaluations.
- Previous studies suggest a link between aminoglycosides and hearing impairment, but data in neonates is limited.
Purpose of the Study:
- To investigate the occurrence of hearing loss in children exposed to long courses or high serum concentrations of tobramycin during the neonatal period.
- To evaluate the relationship between neonatal tobramycin exposure and hearing deficits in early childhood.
Main Methods:
- A pilot case-control study involving 3-4-year-old children.
- Tobramycin exposure data was abstracted from patient files.
- Hearing was assessed using click-evoked oto-acoustic emissions (ce-OAE) and distortion product oto-acoustic emissions (dp-OAE), with brainstem electric response audiometry (BERA) for abnormal results.
- Patients were matched for other risk factors.
Main Results:
- 18 children (9 exposed to tobramycin) were analyzed after excluding those with middle ear effusion.
- Three tobramycin-exposed patients with the longest exposure duration showed undetectable OAEs and confirmed cochlear loss (60-70 dB at 3 kHz) via BERA.
- A trend (P=0.08) was observed between tobramycin exposure and OAE results, but no statistical relation to peak or trough serum concentrations was found.
Conclusions:
- No statistical relationship was found between neonatal tobramycin exposure and hearing loss, likely due to the study's small sample size.
- The findings suggest a need for larger, case-control follow-up studies on hearing in neonates exposed to prolonged courses of aminoglycosides.
- Aminoglycoside ototoxicity remains a concern requiring further investigation in vulnerable neonatal populations.
Objective:
To assess the occurrence of hearing loss in children due to neonatal exposure to long courses of tobramycin and/or high tobramycin serum concentrations.
Methods:
This was a pilot case-control study in 3-4-year old children. Data on tobramycin administration were abstracted from the patient files of an earlier study. Patients exposed in the neonatal period to either long courses (>7 days) or high serum concentrations of tobramycin constituted the study group. The control group consisted of patients without tobramycin exposure. Patients were matched for other risk factor according to criteria of the joint committee on infant hearing. All patients underwent the following investigations: otoscopy and pneumatic otoscopy, followed by impedance audiometry, to exclude middle ear effusion. Click-evoked oto-acoustic emissions (ce-OAE) as well as distortion product oto-acoustic emissions (dp-OAE), tested at f2 frequencies ranging from 1 to 10 kHz, were measured to assess hearing. All patients with abnormal ce-OAE results underwent brainstem electric response audiometry (BERA) as well. Since aminoglycoside ototoxicity is usually bilateral, results were compared per patient and not per ear.
Results:
A total of 29 patients were tested. Eleven patients were excluded due to middle ear effusion. Data for 18 patients were analyzed. In the tobramycin treated group (n=9) both ce-OAE and dp-OAE (at all tested frequencies) were not detectable in six ears of three patients. All other patients had normal ce-OAE's as well as normal dp-OAE's in this frequency range. Difference between the tobramycin treated and control group for OAE as well as dp-OAE showed a trend (P=0.08). In all three patients with undetectable emissions BERA confirmed a cochlear loss of 60-70 dB at 3 kHz in both ears. These three patients had the longest total exposure to tobramycin: 20-24 days and 84-92 mg/kg, respectively. No relation to either peak or trough serum concentrations could be detected.
Conclusion:
There was no statistical relation between hearing loss and tobramycin exposure, probably due to sample size. Our results do indicate a need for a case-control follow-up study of hearing in neonates exposed to long courses of aminoglycosides.
