title: Comparison of subarachnoid anesthetic effect of emulsified volatile anesthetics in rats.
abstract: Spinal cord is an important target of volatile anesthetics in particular for the effect of immobility. Intrathecal injection of volatile anesthetics has been found to produce subarachnoid anesthesia. The present study was designed to compare spinal anesthetic effects of emulsified volatile anesthetics, and to investigate the correlation between their spinal effects and general effect of immobility. In this study, halothane, isoflurane, enflurane and sevoflurane were emulsified by 30% Intralipid. These emulsified volatile anesthetics were intravenously and intrathecally injected, respectively. ED50 of general anesthesia and EC50 of spinal anesthesia were determined. The durations of general and spinal anesthesia were recorded. Correlation analysis was applied to evaluate the anesthetic potency of volatile anesthetics between their spinal and general effects. ED50 of general anesthesia induced by emulsified halothane, isoflurane, enflurane and sevoflurane were 0.41 ± 0.07, 0.54 ± 0.07, 0.74 ± 0.11 and 0.78 ± 0.08 mmol/kg, respectively, with significant correlation to their inhaled MAC (R(2) = 0.8620, P = 0.047). For intrathecal injection, EC50 of spinal anesthesia induced by emulsified halothane, isoflurane, enflurane and sevoflurane were 0.35, 0.27, 0.33 and 0.26 mol/L, respectively, which could be predicted by the product of inhaled MAC and olive oil/gas partition coefficients (R(2) = 0.9627, P = 0.013). In conclusion, potency and efficacy of the four emulsified volatile anesthetics in spinal anesthesia were similar and could be predicted by the product of inhaled MAC and olive oil/gas partition coefficients (MAC × olive oil/gas partition coefficients).
authors: Department of Anesthesiology and Translational Neuroscience Center, West China Hospital, Sichuan University Chengdu, Sichuan, P. R. China.
authors: Jiao
authors: J
authors: Guo
authors: Department of Anesthesiology and Translational Neuroscience Center, West China Hospital, Sichuan University Chengdu, Sichuan, P. R. China.
authors: Cheng
authors: C
authors: Zhou
authors: Department of Anesthesiology and Translational Neuroscience Center, West China Hospital, Sichuan University Chengdu, Sichuan, P. R. China.
authors: Peng
authors: P
authors: Liang
authors: Department of Anesthesiology, West China Second Hospital, Sichuan University Chengdu, Sichuan, P. R. China.
authors: Han
authors: H
authors: Huang
authors: Department of Anesthesiology and Translational Neuroscience Center, West China Hospital, Sichuan University Chengdu, Sichuan, P. R. China.
authors: Fengshan
authors: F
authors: Li
authors: Department of Anesthesiology, Union Hospital of Tongji Medical College, Huazhong University of Science and Technology Wuhan, Hubei, P. R. China.
authors: Xiangdong
authors: X
authors: Chen
authors: Department of Anesthesiology and Translational Neuroscience Center, West China Hospital, Sichuan University Chengdu, Sichuan, P. R. China.
authors: Jin
authors: J
authors: Liu
mesh_terms: D018685:Anesthetics, Inhalation / Q000008:administration & dosage*; D000818:Animals; D004655:Emulsions / Q000008:administration & dosage; D004737:Enflurane / Q000008:administration & dosage*; D005260:Female; D006221:Halothane / Q000008:administration & dosage*; D007278:Injections, Spinal; D007530:Isoflurane / Q000008:administration & dosage*; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage*; D010743:Phospholipids / Q000008:administration & dosage; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077149:Sevoflurane; D013024:Soybean Oil / Q000008:administration & dosage; D013116:Spinal Cord / Q000187:drug effects*
chemical_list: D018685:Anesthetics, Inhalation; D004655:Emulsions; D008738:Methyl Ethers; D010743:Phospholipids; C545823:soybean oil, phospholipid emulsion; D000077149:Sevoflurane; D013024:Soybean Oil; D004737:Enflurane; D007530:Isoflurane; D006221:Halothane
keywords: Emulsified volatile anesthetics; general anesthesia; spinal anesthesia