Mechanism of opioid induced hyperalgesia and its prophylaxis in general anesthesia; an electrophysiological analysis

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K20056
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Anesthesiology
• Research Institution: Osaka City University
• Principal Investigator: FUNAI Yusuke 大阪市立大学, 大学院医学研究科, 講師 (60722486)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 痛覚過敏 / 全身麻酔薬 / 脊髄後角

Outline of Final Research Achievements

We found out that general anesthetics strongly affected on synaptic transmission in the spinal cord dorsal horn in early experiment, therefore more detailed examinations were required. Sevoflurane(SEV)(0.1-2 MAC) inhalation dose-dependently inhibited the nociceptive transmission in spinal cord dorsal horn. On the other hand, desflurane(DES)inhalation at anesthetic concentration(>0.5MAC) had similar effect as SEV, however, DES inhalation at subanesthetic concentration(<0.2MAC) paradoxically enhanced the nociceptive synaptic transmission. Both volatile anesthetics affected on the release of excitatory neurotransmitters from primary afferent fiber terminals, whereas　they had little impact on the inhibitory synaptic transmission. Intravenous propofol had no significant effect on pain modulation. The behavioral test by thermal/cold stimulation also revealed the hyperalgesic property by DES at subanesthetic concentration.

Free Research Field

疼痛学