The Effect On Dosage And Muscle Relaxation Of Cis-atracurium By Different Ways Of Administration On Elderly Patients With Spinal Operation

BackgroundMuscle relaxation medicine is an important component of the general anesthesia drugs,which is used for tracheal intubation and surgery.in order to decrease the associated complications by residual paralysis,using muscle relaxation drug should be as few as possible.At the same time,the different ways of drug delivery may also affect the amount of muscle relaxation drug and muscle tension recovery.Previously,the clinical use of muscle relaxation drug mainly was as single intermittent bolus injection and continuous infusion,which are mainly based on clinical experience of the doctors,it always comes with incomplete block or medication overdose.The physiological function and the organ function of the elderly have changed with the increase of age,and these changes have also caused the corresponding changes in pharmacokinetics and pharmacodynamics.So it is more likely to occur residual paralysis,which may increase the related complications.Postoperative musclerelaxation can lead to(1)increased risk of hypoxia and high blood carbonate;(2)decreased sensitivity of the chemical receptor to hypoxia;(3)the pharyngeal and upper esophageal muscle function not been restored,increased risk of reflux and aspiration;(4)increased risk of postoperative pulmonary complications.At present,due to the development of target controlled infusion(Controlled Infusion Target,TCI)technology,it can be combined with muscle relaxation monitoring to implement the closed-loop TCI,to achieve the scientific use of muscle relaxation drug,but this medication is not clear on the amount of muscle and muscle relaxation of the elderly patients.ObjectiveThis study is aim to monitoring the effect of cis-atracurium by three different administration route,closed-loop TCI,intermittent medicine and sustained infusion,by observation of the dosage and muscle relaxation recovery of the elderly patients with spinal operation when maintaining a constant target muscle relaxation(T1<12%),under the total intravenous anesthesia by midazolam and propofol combined with fentanyl.this study will provide references on the best administration route on elderly patients with spinal operation and rational use of drugs.Methods120 patients undergoing spinal surgery under general anesthesia were randomly divided into 3 groups:closed loop TCI group(group A,40 cases),intermittent administration group(group B,40 cases)and continuous infusion group(group C,40 cases)between November 2014 to July 2015.All patients were given the same vital signs monitoring method,anesthesia induction,anesthesia maintenance,airway management,hemodynamic management,fluid management.To be conscious patients disappeared after calibration,the ulnar nerve for four consecutive TOF monitoring,TOF frequency 2Hz stimulation current intensity 50mA,burst interval for 15s,T1 twitch suppression as judged by muscle relaxant effect of indicator values.Set the depth of muscle relaxation feedback value T1?12%.Group A:closed-loop TCI system with consistant speed for cis-atracurium as 0.33ug/kg/min,increase the rate of drug 5.0 ug/kg/min.When Tl>12%,the injection system automatic infuse cis-atracurium until T1<12%;group B:intermittent administration,when T1>12%,intravenous injecting cis-atracurium as 0.03mg/kg;group C:continuous intravenous injection with cis-atracurium as 3ug/kg/min.When T1>12%intravenous paramagnetic injecting cis-atracurium as 0.03mg/kg.Administration of muscle relaxation of all 3 groups were stopped 30 min before the end of surgery and not given antagonization drug for muscle relaxation until natural recovery in the quiet state.Stop monitoring when TOF returned to TOF = 75%end and remove endotracheal tube when necessary.Recording the duration of muscle relaxation(from the first to the drug to stop the use of T1 to 12%of the time),as well as three groups of patients with muscle relaxation to maintain the amount of time,after the resumption of the pump TOF recovery to 25%,75%time and recovery index(TOF recovery from 25%to 75%).ResultsThere was no significant difference between the three groups in demographic data and preoperative patients' physical condition.There was no significant difference in the amount of anesthetics,the length of operation,and the amount of blood loss during operation in the three groups.There was no significant difference in the duration of muscle relaxation between the three groups(P>0.05).Group A on maintaining muscle relaxation is(27.8±3.6)mg,which is(31.3±4.6)mg for group B and(30.7±3.1)mg for group C.Group A is significantly less than the group B and C(P<0.05).The recovery index of group A was(12.9±2.9)min,which was(18.6±3.1)min for group B and(17.5±3.2)min for group C.The recovery index of group A was significantly shorter than group B and C(P<0.05).ConclusionIt will significantly reduce the dosage of cis-atracurium and shortening the time of muscle relaxation recovery in elderly patients with spinal operation by using closed-loop TCI when compared with intermittent dosing or the continuous infusion.