The effect of dexmedetomidine on amino acid in cerebro-spinal fluid of patients undergoing intracranial tumor surgery / 临床麻醉学杂志

ABSTRACT

Objective To investigate the effect of dexmedetomidine on excitatory aminoacid (EAA)and inhibition of amino acid(IAA)in cerebro-spinal fluid(CSF)of patients undergoing in-tracranial tumor surgery,and to explore the cerebral protective mechanism of dexmedetomidine in neurosurgery.Methods Sixty patients aged 18-64 years old,ASA Ⅰ or Ⅱ,weighing 50-90 kg un-dergoing elective intracranial tumor surgery were randomly divided into dexmedetomidine group (group D)and control group(group C).Dexmedetomidine 1 μg/kg was infused before anesthesia in-duction for more than 10 minutes and pumped continously with 0.2-0.7 μg·kg-1·h-1 in group D, while in group C midazolam 0.03-0.05 mg/kg was injected followed by intermittent administration of 0.03-0.05 mg/kg.BIS value was maintained between 40-50.MAP and HR was recorded at the time points before induction(T0 ),dura mater incision(T1 ),tumor resection(T2 ),at the end of the surgery (T3 ).And we collected CSF at T0 ,T3 ,6 hours after the surgery(T4 ),12 hours after the surgery (T5 ),24 hours after the surgery(T6 ),then the concentrations of EAA and IAA were determined with high-performance liquid chromatography (HPLC)at T0 ,T3 ,T4 ,T5 and T6 .Results The MAP and HR in group D at T1-T3 were much lower than that in T0 and in group C(P <0.05).Compared with T0 ,the Glu and Asp in CSF significantly increased in group C at T3-T6 and were much higher than those in group D (P < 0.05 ),GABA was significantly decreased and much lower than group D(P <0.05).Compared with T0 ,the Glu and Asp in group D at T3-T5 were increased and GABA was decreased, but without statistic significance. At T6 , the values recovered to the level at T0 . Conclusion Dexmedetomidine can be used to maintain hemodynamic stability in intracranial tumor surgery,and may play a role in cerebral protection through inhibiting expression of Glu and Asp (EAA).