The Pharmacodynamics And Pharmacokinetics Of Remifentanil In Patients With Burn

Objective:To survey the plasma concentration of remifentanil in patients with burn injury of different degrees. Investigating the appropriate dose of remifentanil in patients with burn injury of different degrees,and guiding the using of remifentanil in clinic and research the pharmacokinetics of remifentanil in patients with burn.Methods: 45 patients with ASA ???,scheduled for excision and skin graft operation in the Second Affiliated Hospital of Kunming Medical University from March 2016 to January 2017 were selected,and were divided into the three groups with 15 cases in each group:the minor burnt group ( group A ) and the moderate burnt group(group B) and the severe burnt group ( group C). The artery cannulation could be prepared for monitoring and sampling after the patients entered the operation room.Etomidate 0.4mg/kg?fentanyl 3 ? g/kg and rocuronium 0.9mg/kg were used in the induction of anesthesia. Maintenance of anesthesia:using sevoflurane with dexmedetomidine(0.4ug/kg.h) and the TCI of remifentanil(A group : 2.0ng/ml , B group : 4.0ng/ml,C group : 6.0ng/ml). ABP,Sp02,HR,BIS,T,CO,SV at different time(before anesthesia induction and 1,3,5,10,15,20,30,40,50,60,90 minutes after TCI and the time of stopping TCI and 1,3,5,8,10,20 minutes after stopping TCI )were collected,collecting samples from the above time points at the same time and calculating pharmacokinetic parameters.Results: 1.There were no statistical differences about SBP,DBP,MAP of patients in A group during the time points of 5,10,15,20,30,40,50,60,90 minutes after TCI compared with the 20% threshold of the base value (p>0.05), and the above values at the time points of TCI1,TCI3 were lower when compared with the 20% threshold of the base values .There were no statistical differences about HR of patients in A group during all the time points compared with the 20% threshold of the base values(p>0.05). 2.There were no statistical differences about SBP,DBP,MAP of patients in B group during the time points of 1,5,10,15,20,30,40,50,60,90minutes after TCI compared with the 20% threshold of the base values (p>0.05 ),and the above values at the time points of TCI3 were lower when compared with the 20% threshold of the base values; There were no statistical differences about HR of patients in B group at the time point of TCI3 compared with the 20% threshold of the base values (p>0.05 ),and the values of HR during all the other time points were lower when compared with the 20% threshold of the base values . 3.There were no statistical differences about SBP,MAP of patients in C group during the time points of 10,15,20,30,40,50,60,90 minutes after TCI compared with the 20% threshold of the base values (p>0.05),and the above values at the time points of TCII,TCI3,TCI5 were lower when compared.with the 20% threshold of the base values ;There were no statistical differences about DBP of patients in C group during the time points of 1,5,10,15,20,30,40,50,60,90 minutes after TCI compared with the 20% threshold of the base value (p>0.05) , and the above values at the time points of TCI3 were lower when compared with the 20%threshold of the base values ; The values of HR of patients in C group during all the time points were lower compared with the 20% threshold of the base value (p>0.05).4.The values of CO in A group were lower than which in B group and C group at the time of basis(P<0.05), and the values of SV in A group were lower than which in C group at the time of basis(p<0.05). 5.The t1/2 and CL in the minor burnt patients is 8.888min,31.676ml/kg.min; the t1/2 and CL in the moderate burnt patients is 7.845min,22.249ml/kg.min; the tl/2 and CL in the severe burnt patients is 9.426min,29.255ml/kg.min..Conclusions: 1 .It's practicable to use different doses of remifentanil with sevoflurane and dexmedetomidine during the excision and skin graft operation of burnt patients. When using evoflurane with dexmedetomidine(0.4ug/kg.h) to maintain anesthesia , the recommended dose of remifentanil in the minor burnt patients is 2ng/ml,and in the moderate burnt patients is 4ng/ml,and in the severe burnt patients is 6ng/ml, it can provide appropriate depth of anesthesia and maintain stable hemodynamics, and improve the quality and safety of anesthesia. 2.The t1/2 of remifentanil is extension and the CL of remifentanil is decreased during the excision and skin graft operation of burnt patients, we should pay attention to the dosage in clinical work.