The Effect Of Dexmedetomidine Pre-injection On Prevention Of Lidocaine Cardiac Toxicity

Objective:To investigate the effect of dexemedetomidine pre-injection on prevention of lidocaine cardiac toxicity in mature Wistar rats.Methods:Thirty mature Wistar rats were randomized to three groups of 10 rats each to receive pre-injection with dexmedetomidine 0μg/kg (Group A), dexmedetomidine 5μg/kg (Group B), or dexmedetomidine 10μg/kg (Group C). All groups underwent intraperitoneal anesthesia with 4ml/kg 10% Chloral hydrate, noninvasive blood pressure was applied to the rignt femoral,a catheter was inserted in the left femoral vein devoted to medcine infusion.In the experiment groups,1 ml relative dose was infused through the left femoral vein in 10 minutes and then with a continuous lml/h 2% lidocaine infusion with a pump until the rats had the manifestations of poisoning, definded as the ECG waveform changed, including that broadening range>20% of baseline values or arrhythmia, heart rate> 25% of baseline values, MAP decreased>25%.Hardly rats produced poisoning symptoms of local anesthetic when the arterial blood was collected through the right femoral artery, measured the determination of lidocaine concentrations in blood with the High Performance Liquid Chromatography. To analysis the relationship between different concentrations of dexmedetomidine and blood lidocaine concentration.Results:The rats in three groups were similar with regard to weights and hemodynamics (baseline) and there was no significant difference (P>0.05). A group blood concentration of lidocaine poisoning was 1.049±0.883μg/ml, B group blood concentration of lidocaine poisoning was 5.460±1.814μg/ml, C group blood concentration of lidocaine poisoning was 6.066±2.715μg/ml.Conclusion:Pre-injection with dexmedetomidine had a good preventive effect on lidocaine induced cardiac toxicity.