Effect of Thiopental Sodium on Hearing Outcomes Following Microvascular Decompression Surgery. |
Won Ju Kim, Jong Hoon Kim, Sun Jun Bai, Yoon Chang Le, Kyeong Tae Min |
1Department of Anesthesiology and Pain Medicine, Yonsei University College of Medicine, Seoul, Korea. ktmin501@yumc.Yonsei.ac.kr 2Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea. |
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Abstract |
BACKGROUND The use of intraoperative brainstem auditory evoked potential (BAEP) has reduced the incidence of sensorineural hearing loss (SNHL) after microvascular decompression (MVD).
This complication occurs due to direct compressive and/or stretching injury of the cochlear nerve or to indirect compression of the perineural vasculature during cerebellar retraction. The aim of this study was to evaluate the effect of thiopental sodium on SNHL after MVD for hemifacial spasm. METHODS 94 hemifacial spasm patients with normal hearing function preoperatively and who underwent MVD under intraoperative BAEP monitoring were enrolled in this study.
Patients were randomly divided into two groups. 52 patients were administered placebo (control group) and 42 patients were administered thiopental sodium 5 mg/kg intravenously 5 minutes before cerebellar retraction (thiopental group). The effects of thiopental on intraoperative BAEP changes and postoperative hearing functional outcomes were sought.
Incidence and degree of postoperative SNHL were evaluated by pure tone audiometry threshold analysis. RESULTS Maximal changes in intraoperative BAEP parameters did not differ between the two groups, and neither did the incidence nor degree of SNHL. In the control group, 4 transient and 4 permanent postoperative SNHL, including 2 deaf patients, occurred with an overall incidence of 15.4%.
In the thiopental group, 2 transient and 1 permanent postoperative SNHL occurred, with an overall incidence of 7.1%. CONCLUSIONS Thiopental sodium administered prior to cerebellar retraction might reduce the incidence of postoperative hearing loss. |
Key Words:
brainstem auditory evoked potentials; microvascular decompression; sensorineural hearing loss; thiopental sodium |
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