Shifts in auditory brainstem response latencies following plasma-level-controlled aminoglycoside therapy.

The ototoxic effect of plasma-level-controlled netilmicin and tobramycin was monitored in 20 intensive care patients, using auditory brainstem responses (ABRs). ABRs were recorded at the onset and after 6 days of treatment. Significant shifts in the ABR wave V latency were observed independent of the type of medication received or whether the patients were intubated or not. Shifts were also observed in wave I latencies. These latter changes were only significant for the complete population, probably because this potential is more difficult to elicit and measure than is wave V. The I-V interlatency time was greater for netilmicin than for tobramycin. These results indicate that the cumulative effects of aminoglycoside ototoxicity may be different for the central and peripheral nervous systems, and therefore ABR measurements may be the most accurate way of controlling ototoxicity in intensive care patients.