Intravenous injection of 20% lipid emulsion reverses neurotransmitters imbalance in central nerve system induced by local anesthetics / 临床麻醉学杂志

ABSTRACT

Objective To investigate the effect of intravenous injection of 20% lipid emulsion on neurotransmitters imbalance in central nerve system induced by local anesthetics.Methods Thirty adult Sprague-Dawley rats were randomly divided into two groups:normal group (group C,n =10) and local anesthetics group (group L,n =20).Based on different treatment,the rats in group L were assigned into two subgroup:control group (group S,n =10)and 20% long-chain lipid emulsion in-jection group (group I,n =10).The rats of group L were injected with 0.75% levobupivacaine at 50μl/min from the right ventricle of brain.When convulsions wave of electroencephalogram EEG ap-peared,20% long-chain lipid emulsion was administrated continuously 0.25 ml·kg-1 ·min-1 (group I)or normal saline (group S).The rats in group C were without any treatment.All the rats were con-tinously monitored by EEG,ECG and SpO 2 .The primary outcome included seizure duration and threshold and rats’mortality of postoperative 24 h.Secondary outcome included the concentrations of neurotransmitters GABA and Glu in cerebrospinal fluid,expression of NMDAR1 in cortex,Glu/GA-BA concentration ratio (Glu/GABA),and analysis the correlation between expression of Glu and NMDAR1.Results The convulsion time and mortality of rats in group S were significantly increased compared with those in group I (P <0.05).The seizure threshold of levobupivacaine was much lower in group S than group I (P <0.05).Compared with group C,the concentrations of Glu and GABA in cerebrospinal fluid,expression of NMDAR1 in hippocampus and Glu/GABA significantly increased in groups S and I(P < 0.05 ),and at same time these data in group S were significantly higher than group I (P < 0.05 ).There is a positive correlation between concentration of Glu in CSF and expression of NMDAR1 in hippocampus (r =0.884,P <0.01 ).Conclusion Intravenous infusion of 20% long-chain lipid emulsion can effectively improve neurotransmitters imbalance in central nerve system induced by intraventricular injection of local anesthetics.