Predictive value of intraoperative brainstem auditory evoked responses in surgery for conductive hearing losses.

Overview

OBJECTIVE: To assess the efficacy of intraoperative brainstem auditory evoked responses (BAER) in predicting postoperative hearing improvement in surgery for conductive hearing loss. STUDY DESIGN: A prospective study of consecutive patients undergoing surgery for conductive hearing loss under general anesthesia by a single surgeon. SETTING: A tertiary care university affiliated medical center. PATIENTS: All patients undergoing surgery for conductive hearing loss by the senior author between June 25, 1993 and March 20, 1995. INTERVENTIONS: Pre- and postreconstruction intraoperative BAERs; pre- and postoperative pure tone and speech audiometry. MAIN OUTCOME MEASURES: Changes in audiometric pure tone air-conduction thresholds, bone-air gaps (BAG), and speech reception thresholds (SRT), compared with changes in BAER wave five (V) latencies. RESULTS: A decrease in the wave V latency on the intraoperative BAER correlates significantly with improvement in postoperative pure-tone air-conduction, BAG, and SRT using chi 2 and linear regression analyses. CONCLUSIONS: Improvement in intraoperative BAER correlates with postoperative hearing improvement in surgery for conductive hearing loss done under general anesthesia in our population.