Comparative Study On The Analgesic Effect Of Single Femoral Nerve Block And Cocktail Ingection After Total Knee Arthroplasty

ObjectiveTo study the difference of analgesic effect between periarticular injection of cocktails and single femoral nerve block with different concentrations of ropivacaine after total knee arthroplasty(TKA).MethodFrom November 2017 to February 2020,75 patients with unilateral TKA were enrolled in our hospital,19 patients were treated with general anesthesia combined with intraarticular injection of cocktail local analgesia(group A),other patients were treated with single femoral nerve block after general anesthesia,nerve block was divided into group B1 0.2%,n=19;group B2 0.3%,n=1 7;group B3 0.4%,n=20.There was no significant difference in age,sex,BMI,ASA,operation method and type of knee prosthesis among the four groups.The patients in group A were given ropivacaine(100 mg),morphine(5 mg),methylprednisolone(40 mg),epinephrine(25 ug)and tranexamic acid(0.8g)during the operation.In the nerve block group,there was no injection of cocktails during the operation,and ultrasound-guided single block of femoral nerve(30 ml ropivacaine of different concentrations).All the patients in the four groups were given intravenous analgesia(sufentanil lug/kg,dexmedetomidine 2ug/kg,tropisetron 0.2mg/kg).The patient-controlled key of intravenous analgesia was pressed during the acute pain attack.Flurbiprofen axetil(50mg)was given intravenously three days after the joint surgery.The main outcome measures of this study were the first postoperative PCIA self-control pressing time,the total number of PCIA compressions,the VAS score of 6/12/24/48h when resting and moving,the time when theVAS>6,the muscle strength of 6/12/24h and the total days of hospital stay.Result1.There was no significant difference in age,gender,BMI and ASA between the four groups(P>0.05).2.There was no significant difference in the total length of stay between the four groups(P>0.05).3.The VAS scores of rest and movement in group B2 and B3 were better than those in group A and B1,and the time of VAS>6 in group B2 and B3 was significantly longer(P<0.05).Compared with group B2 and B3,the VAS score of resting state at 12 h in group B3 was better than that in group B2(P<0.05),and there was no significant difference between the two groups in resting state at other time points(P>0.05).4.There was significant difference in PCIA first self-control time and total self-control times among the four groups(P<0.05).The time of PCIA first self-control in group B1,B2 and B3 was later than that in group A,and the total number of self-control was significantly reduced compared with group A,and the higher the concentration of effect,the more significant.5.The patients in group A,B1 and B2 were more satisfied with the recovery of muscle strength at 12 h after operation than those in group B3(P<0.05).ConclusionAfter total knee arthroplasty under general anesthesia,0.3%ropivacaine was used for single femoral nerve block under the guidance of ultrasound.The effect of postoperative analgesia was satisfactory,and the recovery of muscle strength was fast,which was helpful for the early functional exercise of affected limbs.