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

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.