Comparison Of Pharmacodynamics Of Cisatracurium And Rocuronium Based On Three Strategies For Elderly Patients

The aging of the population has been becoming more and more serious and has attracted the attention of the whole society.Advances in medical technology have given more elderly the opportunity that seeking positive but risky treatments such as surgery.At present,the safety of general anesthesia has made great progress compared with the past,which provides a safe guarantee for the elderly to receive surgical treatment.However,the perioperative risk of postoperative complications and death in elderly patients is still increasing.To meet the needs of mechanical ventilation and muscle relaxation during general anesthesia,the anesthesiologist would use muscle relaxants when the patient has reached a sufficient depth of anesthesia.In recent years,non-depolarizing neuromuscular blocking drug（NMBD）is becoming the main choice for clinical work.It is mainly divided into benzyl isoquinoline and steroids,which are represented by cisatracurium（CIS）and rocuronium（ROC）.The decline of organ function in the elderly may affect the pharmacokinetics and pharmacodynamics of muscle relaxants,which will prolong the time of clinical action and increase the risk of postoperative complications.A series of clinical studies have confirmed the effect of aging on the metabolism of muscle relaxants.The changes of body function should be taken into account in the use of muscle relaxants in elderly patients.The dosage,interval and intraoperative monitoring should be adjusted accordingly.Muscle relaxant residue may occur in patients with postoperative residual curarization（PORC）.PORC is more likely to occur in elderly patients due to changes in the distribution of muscle relaxants and drug metabolism,and serious complications such as persistent hypoxemia,respiratory accidents and secondary hemodynamic instability occur.The high incidence of severe respiratory events and postoperative pulmonary complications in elderly patients may be due to aspiration,dysphagia and retrolingual fall after anaesthesia resuscitation.Postoperative respiratory insufficiency,atelectasis,hypoxemia,and other severe complications caused by PORC increased the risk of postoperative death.With the deepening of the research on NMBD,some scholars began to question the rationality of using real body weight（RBW）to calculate the drug95%of effective dose（ED95）and to guide the clinical of ED95.Accurating muscle relaxant dosage can reduce the incidence of RNMB to some extent.At present,there are two main directions in the study of precise dosage of muscle relaxants in general anesthesia.The corresponding ED95 was calculated by estimating the body surface area（BSA）and body weight without fat.CIS and ROC are commonly used drugs in clinical anesthesia at present,it is of great clinical significance to study that the pharmacokinetic changes and regimen of two drugs in patients of different ages.Objective:The methods of calculating the induction dose and the supplemental dose of CIS and ROC in perioperative period of general anesthesia based on were compared according to their lean body mass or fat-free body weight,body surface area and their respective ED95,compared with the commonly method of RBW in the elderly patients at the present stage,to explore the selection and dose calculation of muscle relaxant in elderly patients during perioperative period.Methods:96 patients,aged 65 to 90 years,ASA I to III,undergoing elective general anesthesia were randomly divided into 2 groups group C and group R,and each group was randomly divided into three subgroups group CR,group CF,group CB,group RR,group RL,group RB.The inducing dose and supplemental dose of CIS or ROC were different in each group.It was0.15mg/kg CIS for the patients in the group CR,0.1994 mg/kg_FFM CIS for the patients in the group CF,5.58mg/m²_BSA CIS for the patients in the group CB,0.6mg/kg ROC for the patients in the group RR,0.86mg/kg _LBM for the patients in the group RL,16.64mg/m²_BSA for the patients in the group RB respectively.All groups received the same anesthesia management except for different doses of CIS or ROC.The intraoperative and postoperative TOF were monitored by the Ohemda S5,and the inhibition rate of T1,the intubation condition,effective time,no reaction time,clinical action time,additional interval,recovery index,the last administration of the drug and the time of TOFR recovery to 0.9 and TOFR after extubation.All the data were analyzed by SPSS 19.0 software.The measurement data were expressed as mean±standard deviation or median（quartile spacing）.One-way ANOVA,uncorrected Fisher’s LSD was used for those who were consistent with the positive distribution（KS normality test）and the variance was equal through the homogeneity test of variance（Levene test）,and nonparametric tests（Kruska-Wallis H test）were performed for those who did not conform to the standard deviation and the median（quartile spacing）.The count data were tested by chi-square test,the difference was statistically significant（P<0.05）.Results:126 subjects entered the stage of clinical trail,only 96 have finished all process.48 subjects in group C and group R,16 subjects in each subgroup.There was no significant difference in age,sex,ASA status,BMI,RBW,BSA between the two groups（P>0.05）.There was no significant difference in FFM among the 3 subgroups in group C（P>0.05）.There was no significant difference in LBM among the 3 subgroups in group R（P>0.05）.The induced dose and supplemental dose of CIS in group CF was significantly lower than that in group CB（P<0.05）.The induced dose,supplementary dose and dose per kilogram in one hour of ROC in group RB were significantly lower than those in group RR（P<0.05）.The induced dose,supplementary dose and dose per kilogram in one hour of ROC in group RB were significantly lower than those in group RL（P<0.05）.T1 inhibition rate of group C was 100%.The inhibition rate of the group RB was significant lower than it in group RR（P<0.05）,The inhibition rate of the group RB was significant lower than it of group RL（P<0.05）.The onset time of group CB was significant longer than it in of group CR（P<0.05）.The onset time of CB was significant longer than it in of group CF（P<0.05）.The onset time of group RL was significant shorter than it of group RR（P<0.05）.The onset time of group RR was significant shorter than it of group RR（P<0.05）There was no significant difference in no reaction time among the three subgroups in group C（P>0.05）.The no reaction of group RB was significant shorter than it of group RL（P<0.05）.There was no significant difference in clinical time among the three subgroups in group C（P>0.05）.The clinical time of group RB was significant shorter than it of group RR（P<0.05）.The clinical time of group RB was significant shorter than it of group RL（P<0.05）.There was no significant difference in clinical time among the three subgroups in group C（P>0.05）There was no significant difference in the additional interval between the three subgroups in group C（P>0.05）。The additional interval of group RB was significant shorter than it of group RR（P<0.05）.The additional interval of group RB was significant shorter than it of group RL（P<0.05）.There was no significant difference in the recovery index between the three subgroups in group C（P>0.05）.The recovery index of group RB was significant shorter than it of group RR（P<0.05）.The recovery index of group RB was significant shorter than it of group RL（P<0.05）.There was no significant difference between the three subgroups of group C in the time between the last administration of the drug and the time ofTOFR recovery to 0.9（P>0.05）.The last administration of the drug and the time of TOFR recovery to 0.9 of group RB was significant shorter than it of group RR（P<0.05）.The last administration of the drug and the time of TOFR recovery to 0.9 of group RB was significant shorter than it of group RL（P<0.05）.There was no significant difference in TOFR value between the three subgroups in the C group（P>0.05）.There was no significant difference in TOFR values between different time periods in each subgroup in group C（P>0.05）.There was no significant difference in the number of subjects with TOFR<0.9 in each period of PACU in group C（P>0.05）.There was no significant difference in the number of subjects with TOFR<0.9 in 15^th min and 30^th min of PACU in group R（P>0.05）.The value of subjects with TOFR<0.9 in 60th min of RB was higher than it of group RL（P<0.05）.There was no significant difference in TOFR values between different time periods in each subgroup in group C（P>0.05）.。There was no significant difference in the number of subjects with tofr<0.9 in PACU in group R.（P>0.05）。Conclusions:Based on FFM to calculate the perioperative dosage of CIS in elderly patients can reduce the dose of inducer and add dose and maintain the effective muscle relaxation effect.Based on BSA to calculate the perioperative dosage of ROC in elderly patients can reduce the dose of inducer and add dose,but it can shorten the interval of supplementation obviously.60min of PACU monitoring in elderly patients may help to reduce the incidence of PORC.