Evaluation of Hearing Loss after Spinal Anesthesia with Otoacoustic Emissions

The aim of this study was to determine the degree and reversibility of hearing loss (HL) following spinal anesthesia with an objective audiometric test: otoacoustic emissions (OAE). Eleven patients (22 ears) who were undergoing surgery under spinal anesthesia were included in this study. Transient-evoked otoacoustic emissions (TEOAE) and distortion product otoacoustic emissions (DPOAE) were evaluated 1 day before the operation and postoperative day 1, 2, and 15. DPOAE were recorded as DPgram and input/output functions (I/O). The emission amplitudes of the TEOAE and DPOAE of right and left ears were found to be affected immediately after the surgery and progressive improvement detected with full recovery within postoperative 15 days. These changes were mainly at around 1,500–3,000 Hz. None of the patients had permanent OAE amplitude deterioration. Transient HL may occur more often than it is generally assumed, and the symptoms might not be recognized. OAE is an effective and objective way of evaluating the HL in this particular group of patients. We suggest informing patients about this transient HL for medicolegal issues.