title: Cochlear Function Monitoring after Spinal Anesthesia.
abstract: BACKGROUND
  The aim of the study was to examine the effect of spinal anesthesia on the function of cochlear outer hair cells (OHCs), determined by means of objective distortion product otoacoustic emissions (DPOAE) testing. To the best of our knowledge, our study was the second OAE-based analysis of cochlear function during spinal anesthesia, and the only experiment including such a large group of patients.
  
  
  METHODS
  The study included 20 patients (18 men and 2 women) subjected to a scheduled uretherorenoscopic lithotripsy with routine spinal anesthesia with 10 mg (2 ml) of 0.5% hyperbaric bupivacaine and 50 μg (1 ml) of fentanyl. The levels of DPOAEs and background noise at 1000-6000 Hz were recorded prior to and immediately after the anesthesia, and on the postoperative day 2.
  
  
  RESULTS
  We did not find significant differences between DPOAEs values recorded prior to and immediately after the anesthesia. The only exception pertained to 5652 Hz, at which a significantly higher level of DPOAEs was observed immediately after the anesthesia. The levels of DPOAEs at 2002 Hz and 2380 Hz collected on the postoperative day 2 were significantly higher than the respective baseline values. Irrespective of the frequency and time of testing, we did not find any significant differences between the recorded levels of background noise.
  
  
  CONCLUSIONS
  Our findings point to the lack of a detrimental effect of spinal anesthesia on objectively evaluated cochlear function, and thus suggest that this method is safe, even for OHCs, which are extremely susceptible to exogenous and endogenous injuries.
authors.affiliation: Department of Anesthesiology and Intensive Therapy in Zabrze, Medical University of Silesia, Zabrze, Poland.
authors.forename: Agata
authors.initials: A
authors.lastname: Janecka-Placek
authors.affiliation: Department of Otolaryngology in Zabrze, Medical University of Silesia, Zabrze, Poland.
authors.forename: Grażyna
authors.initials: G
authors.lastname: Lisowska
authors.affiliation: Department of Urology in Zabrze, Medical University of Silesia, Zabrze, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Paradysz
authors.affiliation: Department of Anesthesiology and Intensive Therapy in Zabrze, Medical University of Silesia, Zabrze, Poland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Misiołek
mesh_terms: D000161:Acoustic Stimulation; D000293:Adolescent; D000328:Adult; D000775:Anesthesia, Spinal / Q000009:adverse effects / Q000379:methods*; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold / Q000502:physiology; D002045:Bupivacaine / Q000627:therapeutic use; D003051:Cochlea / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005283:Fentanyl / Q000627:therapeutic use; D018072:Hair Cells, Auditory, Outer / Q000187:drug effects / Q000502:physiology*; D006320:Hearing Tests; D006439:Hemodynamics; D006801:Humans; D008096:Lithotripsy; D008297:Male; D008875:Middle Aged; D017084:Otoacoustic Emissions, Spontaneous / Q000187:drug effects / Q000502:physiology; D011184:Postoperative Period; D013997:Time Factors; D055815:Young Adult
chemical_list: D005283:Fentanyl; D002045:Bupivacaine