Rate of false-positive results for threshold shifts during initial treatment with aminoglycosides
Nicolas Schmuziger1, Nicolas Gürtler, Manuel Jungi
1Department of Otorhinolaryngology, University Hospital, Basel, Switzerland. nschmuziger@uhbs.ch
Abstract:
Specific recommendations from the American Speech-Language Hearing Association (1994) exist for the audiometric surveillance of patients receiving aminoglycoside therapy. However, these recommendations are not based primarily on test-retest repeatability in often seriously ill patients. The probability of ototoxicity is very low during the first three days of aminoglycoside therapy, and significant threshold shifts can be assumed to represent a false-positive result. Baseline thresholds were measured in 28 patients before or not later than 24 h after the beginning of aminoglycoside therapy. These measurements were repeated in 22 patients during the first three days of the drug administration. Three out of 22 patients fulfilled the American Speech-Language-Hearing Association's (1994) criteria for cochleotoxicity making up a false-positive rate of 13%. In actual patients, the false-positive rate of audiometric surveillance during ototoxic drug administration may be substantially higher than in healthy subjects when these criteria are used.
Insights
Aminoglycoside ototoxicity monitoring using American Speech-Language-Hearing Association guidelines may yield high false-positive rates in seriously ill patients. Early-stage threshold shifts often do not indicate true hearing damage from these drugs.
Area of Science:
- Otolaryngology
- Pharmacology
- Audiology
Background:
- Current American Speech-Language-Hearing Association (ASHA) guidelines (1994) exist for audiometric surveillance during aminoglycoside therapy.
- These ASHA recommendations are not primarily based on test-retest repeatability in critically ill patients, potentially impacting accuracy.
- Ototoxicity from aminoglycosides is unlikely within the first three days of therapy.
Purpose of the Study:
- To evaluate the test-retest repeatability of ASHA audiometric surveillance criteria in patients receiving aminoglycoside therapy.
- To determine the false-positive rate of ASHA criteria for cochleotoxicity in this patient population.
Main Methods:
- Audiometric baseline thresholds were measured in 28 patients before or within 24 hours of aminoglycoside initiation.
- Thresholds were repeated in 22 of these patients during the initial three days of aminoglycoside administration.
- ASHA (1994) criteria for cochleotoxicity were applied to assess threshold shifts.
Main Results:
- Three out of 22 patients (13% false-positive rate) met the ASHA criteria for cochleotoxicity.
- Significant threshold shifts during the first three days of therapy may represent false positives in clinical practice.
- The observed false-positive rate suggests potential overestimation of ototoxicity when using current ASHA criteria in this context.
Conclusions:
- The ASHA (1994) criteria for audiometric surveillance may result in a substantial false-positive rate for ototoxicity in patients undergoing aminoglycoside therapy.
- Clinical interpretation of audiometric results during the early phase of aminoglycoside treatment should consider the low probability of early ototoxicity.
- Further research is needed to refine audiometric surveillance protocols for aminoglycoside therapy, especially in vulnerable patient groups.
