[Current status of intraoperative motor evoked potential monitoring: a questionnaire study].

BACKGROUND: Intraoperative motor evoked potential (MEP) monitoring has been used for the purpose of preventing neural complications in surgical treatments. There is little information about the current status of intraoperative MEP monitoring in Japan. METHODS: The survey targeted anesthesia departments mainly of university hospitals throughout the country. RESULTS: Answers were obtained from 60 institutions (a response rate of 68%). Intraoperative MEP has been monitored in 58 institutions. Intraoperative MEP monitoring in 35 institutions did not exceed 50 times per year. Especially during thoracoabdominal aortic aneurysm repair, frequency of MEP monitoring in 51 institutions was limited to 10 times per year. A few anesthesiologists were concerned with evaluation of MEP in craniotomy and spine surgery. In contrast, anesthesiologists in 15 institutions were responsible for evaluation of MEP during thoracoabdominal aortic aneurysm repair. Warning criteria of MEP and therapeutic strategies in case of critical MEP change differed by institution. Fifty four responders expected a guideline for clinical use of intraoperative MEP monitoring. CONCLUSIONS: A clinical practice guideline for intraoperative MEP monitoring based on the information from previous investigations and a planned multicenter clinical study is necessary to enhance its utility.