Effect Of Dexmedetomidine On The Dose-response Relationship Of Sufentanil Inhibiting Tracheal Intubation Response In Patients Undergoing Coronary Artery Bypass Grafting

Objective To explore the effect of dexmedetomidine on the dose-effect relationship of sufentanil in inhibiting endotracheal intubation response in patients undergoing coronary artery bypass grafting before induction of general anesthesia,and to determine the half effective dose?ED50?,ED95 and 95%confidence interval of sufentanil in inhibiting endotracheal intubation response.Methods Eighty-eight patients were selected to receive coronary artery bypass grafting at the Yantai Yuding Hospital affiliated to Qingdao University.46 males and 34females,body mass index 18.6-23.5 kg/m²,ASA physical status II and III,inclusion criteria included all patients aged 48 to 65 years scheduled for coronary artery bypass grafting,with no?₂ receptor agonist was used for 2 weeks before surgery.The random number table method was divided into the dexmedetomidine group?group D,n=40?and the control saline group?group C,n=40?.In group D,the dexmedetomidine?concentration:4?g/mL?0.5?g/kg was injected intravenously within 10 minutes before general anesthesia induction,the normal saline group received intravenous pumping of equal volume normal saline 10min before the induction of general anesthesia.After the pump was completed,the general anesthesia was induced with midazolam 0.05 mg/kg,sufentanil,etomidate 0.2 mg/kg.When the BIS value was less than 60,cisatracurium was given 0.2 mg/kg,and sufentanil was given for 5 minutes before endotracheal intubation under the visual laryngoscope of the same anesthesiologist.These data were heart rate?HR?,systolic blood pressure?SBP?,diastolic blood pressure?DBP?and mean arterial pressure?MAP?at baseline?T₁?,before induction?T₂?,before intubation?T₃?,immediately after intubation?T₄?,incision?T₆?.At the non-infusion side,3mL of venous blood was collected from?T₁?tracheal intubation immediately after intubation?T₄?,and norepinephrine?NE?and epinephrine?E?plasma cortisol were measured by enzyme-linked immunosorbent assay?elisa?.At any two moments,the changes of MAP and SBP were more than 20%or HR more than 90 times/min,which were positive for endotracheal intubation response,while negative for endotracheal intubation response.The modified sequential method was used to determine the dose of sufentanil induced by anesthesia.The first patient had a dose of sufentanil of 0.5?g/kg,and the case of positive tracheal intubation was followed by a high dose of sufentanil.If the tracheal intubation reaction is negative,the next case uses a lower dose.The Probit method was used to determine the ED50 and 95%confidence interval of sufentanil.The hormone response at different times was inversely evaluated for the body's stress response.Results There was no significant difference in T₁-T₅ heart rate,systolic blood pressure,diastolic blood pressure and mean arterial pressure between the dexmedetomidine group and the normal saline group?P>0.05?,but the dexmedetomidine group contracted.The changes of pressure,diastolic blood pressure,mean arterial pressure and heart rate were significantly smaller than those in the saline group?P<0.05?.In the dexmedetomidine group,the ED50 of sufentanil to inhibit endotracheal intubation response was 0.408?g/kg,with a 95%confidence interval?0.341-0.467?g/kg?;ED95 was0.55?g/kg,with a 95%confidence interval?0.482?1.036?g/kg?.The ED50 for sufentanil inhibition of tracheal intubation was 0.461?g/kg,95%credible Interval?0.342-0.579?g/kg?;ED95 was 0.669?g/kg,with a 95%confidence interval?0.563?2.336?g/kg?.There was no significant difference in plasma norepinephrine,adrenaline,and cortisol concentrations between the two groups at time T₁?P>0.05?.The concentrations of plasma norepinephrine,adrenaline,cortisol and concentration in the dexmedetomidine group at T₄ and T₆ were significantly lower than those in the saline group?P<0.05?.Conclusion For patients undergoing elective coronary artery bypass grafting,the infusion of dexmedetomidine 0.5?g/kg before induction of general anesthesia can reduce the dose of sufentanil inhibiting the response to endotracheal intubation and reduce the stress response during induction of general anesthesia.