The Effects Of Dexmedetomidine On The Occurrence Of Shivering In Cesarean Section During Combined Spinal-epidural Anesthesia

Objective:To investigate the effects of dexmedetomidine on the occurrence of shivering in cesarean section during combined spinal-epidural anesthesia Methods:In this experiment, 62 patients undergoing cesarean section were selected from the Department of obstetrics of the our hospital. All cases were divided randomly into three groups:A group(dexmedetomidine 0.5μg/Kg, n=19)、B group(dexmedetomidine 0.3μg/Kg,n=23)and C group(normal saline,n=20). After the combined spinal-epidural anesthesia puncture success,subarachnoid give 2ml of the total 2.5ml of mixture which included 2ml of the 0.75% bupivacaine and 0.5ml of the 10% Glucose Injection, and then placed the epidural catheter, then helped the parturient to supine position. Started the operation after maintaining the level of anesthesia at T6~S5. After the delivery of fetus and cutting the umbilical cord, Group A and group B respectively received dexmedetomidine 0.5μg/Kg, 0.3μg/Kg as group C received saline 0.9%, all drugs pumped injection intravenously constant speed for 10 minutes. During the operation,we measured and recorded pulse oxygen saturation(SPO2),heart rate(HR),systolic blood Pressure( SBP), mean arterial pressure( MAP),Diastolic Blood Pressure(DBP),respiratory frequency(RR),modified OAA/S score(MOAA/S)at the fallowing time points: before anesthesia(T0), after intravenous administration 10min(T1), 15min(T2), 20min(T3), 30min(T4), 60min(T5). Incidence and severity of shivering were recorded too. Record the occurrence of adverse reaction during anesthesia and local anesthetic dosage, the mount of liquid input. Wrench Shivering grading: grand 0 for no shivering; grand 1 for piloerection or(and) peripheral vasoconstriction or(and) peripheral cyanosis, but no muscle fibrillation; grand 2 is only a group of muscle fibrillation; grand 3 is more than one group of muscles fibrillation(not spread to the whole body) muscle tremors; grand 4 for the whole body muscles fibrillation. Improvement of alertness/sedation scale(modified OAA/S score):grand 1:fully awake, responses normally to the normal name calling; grand 2: responses to slow the normal call names; grand 3: no response to the normal name calling, responses to repeatedly shouted the name. Grand 4: complex shouted without response, only the response to pat the body; Grand 5: to take the body without response, but a response to noxious stimulation. No reaction to noxious stimulation then judge d anesthesia.Statistical analyzes were performed using SPSS13.0 statistical software for statistical analysis, the measurement data are presented as mean ± standard deviation, among the groups using one-way analysis of variance(ANOVA), count data expressed as a percentage using Chi-square test. P <0.05 was considered statistically significant. Results:The incidence of shivering in A and B group were significantly lower than C group(P <0.05),the difference was statistically significant. The sedation satisfaction rate in A group were better than C group in T1、T2 and T3;the sedation satisfaction rate in B group were better than C group in T1、T2 and P<0.05;the difference was statistically significant. HR in A group were significantly lower than C group in T1、T2、T3 and T4;HR in B group were significantly lower than C group in T1、T2 and T3,and P<0.05.RR in A group were higher than C group in T1、T2 and T3;RR in B group were higher than C group in T1、T2 and P<0.05;the difference was statistically significant. There were no significant difference in SBP、DBP and Sp O2 among the three groups throughout the experiment(all P > 0.05). Conclusion:The application of dexmedetomidine for maternal in cesarean section during combined spinal-epidural anesthesia, provides a good sedation, which can not affect the metabolism of oxygen supply and demand for the maternal. Meanwhile, the inhibition of sympathetic nerve reflex by dexmedetomidine provide a good hemodynamic transition for maternal after the delivery of fetus;weaken maternal’s pathophysiologic changes in cardiovascular system due to before and after childbirth. The pre intravenous pump injection of 0.3μg/kg and 0.5μg/kg dexmedetomidine were able to effectively reduce the incidence of shivering during combined spinal-epidural anesthesia, improved the degree of comfortable for maternal and reduced the complication of operation and anesthesia due to shivering, finally to improve the security of the cesarean section operation maternal.