Patients Under Genera Anesthesia Induction Intravenous Fentanyl Induced Cough The ED₅₀ And The Age Influence For It

Objective: In order to get the ED₅₀of Fentanyl-induced cough, for thebetter to prevent the incidence of Fentanyl-induced cough, to provide the safeand effective dosage for the clinical.Methods: Ninety patients divided into two groups by age, the ASA I^II.The range of age in Group A is from18to50, and Group B is from51to70,without limited the gender. The order and dosage of induction is midazolam0.05mg/kg，fentanyl，The cis-regulatory benzene sulfonic acid0.15mg/kg，etomidate0.3mg/kg。The starting dose of fentanyl in both groups is2μg/kg,andthen by sequential method，if the first patient have no cough in each group, theinduction dosage of fentanyl in next patient should increase an dose gradientï¼›on the contrary, the induction dosage of fentanyl in next patient shoulddecrease an dose gradient, until there are intersections from the positive resultsto negative results or from the negative to positive results.The dose gradientof fentanyl is0.5μg/kg, and the time of injection is5second. The medianeffective dose of fentanyl is calculated by logED50=∑nlogx/∑n, and then getthe95%confidence interals by logED50±1.96SxlogED50.Results: There were41patients in group A,21patients had cough amongthem, the others had no cough, the incidence of cough was48.8%,10patientshad light cough,6patients had moderate cough, and4patients had severecough. The average time of cough was7.20±1.824秒. The calculatedresults:ED50=3.78μg/kg。 The95ï¼…confidence interals of ED₅₀was3.56μg/kg～4.00μg/kg。There were26patients in group B, the incidence ofcough was35%,6patients had light cough,3patients had moderate cough, and no patients had severe cough. The average time of cough was9.78±1.302秒.The ED50of Fentanyl-induced cough5.09μg/kg。The95ï¼…confidence interalsof ED50was4.61μg/kg～5.56μg/kg。the difference of the time of cough wassignificant（P<0.05）Conclusion: The ED50of fentanyl-induced cough in group A is3.78μg/kg,and the95ï¼…confidence interals of ED50is3.56μg/kg～4.00μg/kgï¼›The ED50offentanyl-induced cough in group B is5.09μg/kg, and the95ï¼…confidenceinterals of ED50is4.61μg/kg～5.56μg/kg. The difference of the incidence offentanyl-induced cough between the two groups was significant（P<0.05）,andthe difference of the time of cough was also significant（P<0.05）.