The auditory brainstem response: Latencies obtained in children while under general anesthesia

Background: The auditory brainstem response (ABR) test is frequently employed to estimate hearing sensitivity and assess the integrity of the ascending auditory system. In persons who cannot participate in conventional tests of hearing, a short-acting general anesthetic is used, recordings are obtained, and the results are compared with normative data. However, several factors (e.g., anesthesia, temperature changes) can contribute to delayed absolute and interpeak latencies, making it difficult to evaluate the integrity of the person's auditory brainstem function. Purpose: In this study, we investigated the latencies of ABR responses in children who received general anesthesia. Research Design: Between subject. Study Sample: Twelve children between the ages of 29 and 52 mo, most of whom exhibited a developmental delay but normal peripheral auditory function, comprised the anesthesia group. Twelve participants between the ages of 13 and 26 yr with normal hearing thresholds comprised the control group. Data Collection and Analysis: ABRs from a single ear from children, recorded under general anesthesia, were retrospectively analyzed and compared to those obtained from a control group with no anesthesia. ABRs were generated using 80 dB nHL rarefaction click stimuli. T-tests, corrected for alpha slippage, were employed to examine latency differences between groups. Results: There were significant delays in latencies for children evaluated under general anesthesia compared to the control group. Delays were observed forwave V and the interpeak intervals I-III, III-V, and I-V. Conclusions: Our data suggest that caution is needed in interpreting neural function from ABR data recorded while a child is under general anesthesia.