Effects Of Epinephrine Combined With Ephedrine On Maternal Heart Rate Variability In Caesarean Section

Objective:Hypotension after anaesthesia is a serious complication of cesarean section,and the use of vasopressor agents is highly recommended in many interventions.Using blood pressure and heart rate to evaluate the effect of vasopressor agents in previous study is not comprehensive,by observing the influence of vasopressor to maternal heart rate variability and seek stable optimal regimen of the autonomic nervous system has great significance.Method:90 cases of single born pregnant women who underwent elective caesarean section from November 2016 to June 2017 with the Shengjing Hospital of China Medical University,ASA?-? level,were randomly divided into 3 groups according to random number table,30 cases in each group.Use vasoactive drug to treat the depression of blood pressure after spinal anesthesia which was defined as 20% down compared with basic value or systolic blood pressure is lower than 90 mm Hg.Group E for ephedrine 0.15 mg·kg-1;group P for phenylephrine 1 ?g·kg-1;group E + P for combination of ephedrine 0.1 mg·kg-1 and phenylephrine 0.5 ?g·kg-1.Respectively record SBP,HR and heart rate variability low frequency(LF),heart rate variability high frequency(HF)and LF/HF before anesthesia(T0),1 min after subarachnoid injection medicine(T1),vasopressors injection when minimum blood pressure(T2),and for 3 min(T3),5 min(T4),10 min(T5)after injection.T test was used to compare the time points(T1-T5)with T0 of each group,to determine whether there is statistical difference.Result:In group E,LF and LF/HF in T3-T5 was significantly higher than T0,HF was significantly lower than T0,which was statistically significant(P<0.05).In group P,LF and LF/HF in T3 was significantly higher than T0,HF was significantly lower than T0,which was statistically significant(P<0.05).There was no statistical significance(P > 0.05)in group P of LF,HF and LF/HF at T4 and T5 compared with T0;compared with LF,HF,and LF/HF at T0,there was no significant difference in E+P group at T3-T5(P>0.05).Conclusion: Surgery for cesarean section of maternal,combination of phenylephrine and ephedrine can maintain the balance of autonomic nervous for sympathetic and vagal,stabilizing LF,HF and LF/HF in the normal state,which is conducive to heart rate variability stability,which is the recommended choice for hypotension after anaesthesia in caesarean section.