Clinical Study Of Ultrasound-guided Ropivacaine Femoral Nerve Block For Postoperative Analgesia After Total Knee Arthroplasty

Objective:To analyze the analgesic effect of ultrasound-guided ropivacaine femoral nerve block after total knee arthroplasty(TKA),to provide scientific guidance for the formulation of post-TKA analgesic program,to improve the analgesic effect of patients,to optimize the effect of surgical rehabilitation,and to improve the prognosis.Methods:Eighty-six patients who undergoing total knee arthroplasty from May 2016 to August 2017 in No 82 Hospital were selected as the study subjects.They were divided into control group and observation group according to the stochastic principle 43 cases in each group.All patients are executed general anesthesia.The patients in the control group received continuous intravenous fentanyl injection for analgesia.The patients in the observation group received continuous femoral nerve block with 0.2% ropivacaine under ultrasound guidance for analgesia.The analgesic effects of the two groups were compared.The comparative indicators were as follows:(1)Visual analogue pain score(VAS)was used to evaluate the degree of resting pain and active and passive pain in the two groups at 4,6,12,24 and 48 hours after operation;(2)The active knee flexion angles of the affected limbs were measured at 4,6,12,24 and 48 hours after operation;(3)Myodynamic score of the patients in the two groups were evaluated at 4,6,12,24 and 48 hours after operation;(4)Cognitive function was assessed by MMSE on the 1st day beforer operation,and1 st,4th and 7th day after operation,MMSE score below 23 was divided into Postoperative cognitive dysfunction(POCD).The incidence of POCD was counted on the 1st,4th and 7th day after operation;(5)The total incidence of adverse reactions at 48 h after operation was counted;(6)The satisfaction of patients in the two groups was investigated by satisfaction score.Combined with the above indicators,the clinical application value of the two analgesic schemes was evaluatedcomprehensively.Results:(1)Patients in the observation group after 4h,6h,12 h,resting VAS,24 h,48h scores were significantly lower than the control group,there was statistically significant difference,(P < 0.05);The patients in the observation group after 4h,6h,12 h,24h,48 h and VAS scores were significantly lower than passive activities the control group,there was statistically significant difference(P < 0.05).(2)The postoperative flexion angles of 4h,6h,12 h,24h and 48 h in the observation group were significantly higher than those in the control group,and the difference was statistically significant(P < 0.05).(3)The muscle strength scores of 4h,6h,12 h,24h and 48 h in the observation group were significantly higher than those in the control group,and the difference was statistically significant(P < 0.05).(4)Postoperative,1st,4th day observation group MMSE scores were significantly higher than the control group,the difference was statistically significant,(P < 0.05);Postoperative 7th day MMSE score of two groups level,compared to small(P > 0.05);After 1st,4th day of the observation group the incidence of POCD respectively.Are all lower than the control group,the difference was statistically significant(P < 0.05).(5)In the observation group,4 patients had nausea,vomiting,hypoxia and other adverse reactions.The incidence rate was 9.30%(4/43).In the control group,13 patients had adverse reactions,the incidence rate was 30.23%(13/43),the difference was statistically significant(P < 0.05).All patients' adverse reactions were treated with symptomatic treatment,which were all improved and recovered within 1 weeks.No serious adverse effects were caused to the operation.(6)The satisfaction degree of the observation group was 95.35%(41/43),while that of the control group was 79.07%(34/43).The observation group was significantly higher than the control group,the difference was statistically significant(P < 0.05).Conclusion:Ultrasound-guided 0.2% ropivacaine continuous femoral nerve block for analgesia after TKA is superior to fentanyl for continuous analgesia,which can effectively relieve postoperative pain,improve the knee flexion angle and musclestrength of the affected limb,and also can reduce the incidence of adverse reactions such as nausea,vomiting,hypoxia and POCD,significantly improve patient satisfaction.