Effect Of Different Concentration Of Esmolol For Anesthesia Induction On Intraoperative Neuromonitoring During Thyroidectomy

objective The incidence of throid tumor is increasing worldwiderecently. Recurrent laryngeal nerve are usually injured duringthroidectomy. The incidence of injure will be decreased by intraoperativenerve monitoring (IONM). Low dose neuromuscular agents are usedduring IONM, which will lead to intubation response. This researchintends to observe the effect of different concentration of esmolol foranesthesia induction on intraoperative neuromonitoring duringthyroidectomy and proper doses of esmolol.Methods80ASA Ⅰor Ⅱ patients undergoing thyroidectomy wererandomly divided into4groups: group A、B、C、D. They are aging from22to65years old,40males and40females, including45patients withbenign tumor and35patients with malignant tumor.All the patients were established venous access after entering theoperation. ECG,BP,SPO2were monitored, and another arm wasconnected to TOF-Watch SX accelerometry which was used to monitorthe quantitative degree of neuromuscular transmission by stimulatingulnar nerve. Patients were received2mg midazolam,2mg/kg propofol,0.5ug/kg sufentanil When their cardiovascular system remained steady for5minutes. After anesthesia induction, group A、B、C、D wereseparately received10ml saline,0.5mg/kg esmolol,1mg/kg esmolol,1.5mg/kg esmolol. TOF accelerometry was turned on after patients’consciousness disappearing.When Th1reached100%for3minutes, allthe patients were received0.3mg/kg rocuronium. When the twitchreached the lowest level, an EMG endotracheal tube was inserted by anexperienced anesthesiologist.Scores of intubating conditions, heart rate(HR), systolic pressure(SP),and diastolic pressure (DP) were recorded before induction, afterinduction, at the time of intubation,1min,3min,5min after intubation.Results There was no significantly difference between four groupsfor the scores of intubating conditions (P>0.05). HR of group A andgroup B at the time of intubation and after intubation was greater thanthat after induction (P<0.05). HR of group C and group D at the time of3min after intubation was greater than that after intubation (P<0.05). HRand SP of group C and group D were lower than that of group A afterinduction (P<0.05).The incidence of bradycardia in group D was greaterthan that in group C (P<0.05).Conclusions Both doses of1mg/kg and1.5mg/kg of esmolol canprevent effectively response to tracheal intubation.1mg/kg esmolol is anoptimal dose for intraoperative neuromonitoring during thyroidectomy, which can keep the hemodynamy steady.