Optimum Click Rate for Neurodevelopmental Evaluation Using Auditory Brainstem Response in Premature Infants

Abstract

To determine the optimal click rate (CR) for neurodevelopmental assessment using auditory brainstem evoked response (ABR) in preterm infants. A prospective study was performed in 17 preterm infants at 34 weeks' postmenstrual age. Three separate ABRs were performed a few minutes apart on each subject using three different click rates (CRs): 19.9/s, 29.9/s, and 69.9/s. An ABR response with waves I, III, and V identifiable and measurable was defined as a pass response. The CR associated with the highest frequency of pass responses was considered optimal, or if two CRs were tied for the highest frequency, then the faster of the two CR was deemed best. The frequency of pass responses for 29.9/s and 19.9/s CR was 100% and was significantly higher compared with 82% frequency with 69.9/s CR. There was no difference in latencies, interpeak latencies, and amplitudes of waves between 19.9/s and 29.9/s CR; however, standard deviations of interpeak latencies were larger with 19.9/s compared with 29.9/s CR. Our data suggest that 29.9/s is the optimal CR for neurodevelopmental assessment using ABR. Because of smallest variance in interpeak latencies, the sample size requirement will be lowest using 29.9/s CR with secondary reduction in cost and time.