Clinical Study Of Continuous Femoral Never Block For Post Operative Analgesia On Patien-Ts Undergoing Total Knee Arthroplasty

Objectives The purposes of this study were to compare the validity of continuous femoral nerve block (CFNB) and patient controlled intravenous analgesia (PCIA) for analgesia after total knee arthroplasty (TKA), and to assess the knee functional status of the patients using different method for analgesia in order to analysis the influence of pain in the function status.Methods The medical treatment in this research was permitted by Ethics Committee of the First Affiliated Hospital of Chongqing Medical University. Every patient signed an informed-consent of CFNB or PCIA before the operation. This study was carried out on forty patients who underwent unilateral TKA for osteoarthritis. ASA grade1-2, age (65±5) year, weight (62±8) kg.They were divided into continuous femoral nerve block for analgesia group (CFNB group,n=20) and patient controlled intravenous analgesia (PCIA) group (PCIA group,n=20) randomly. Each patient in CFNB group was placed a perineural catheter for CFNB guided by ultrasonography combined with nerve stimulation before the operation, and given2%lidocaine10ml and1%ropivacaine10ml as initial dose. Then the catheter was connected to a pump. Each patient received perineural ropivacaine of0.2%(basal5ml/h, bolus5ml, lockout of30min). Each patient in PCIA group was established intravenous channel before the operation. IV-PCA (tramadol800mg+flurbiprofen axetil100mg+dexamethasone5mg+normal saline to solution80ml in total) which was programmed to deliver the continuous infusion (basal1ml/h, bolus2ml, lockout of15min) was available to all patients in PCIA group. The outcomes included visual analogue scale (VAS) scores at rest, initiative exercise and continuous passive movement (CPM) on4h,8h,12h,24h,36h,48h,72h after the TKA, tramadol dose by intramuscular injection, the presses of the pump, the efficient presses, knee flexion angle at initiative exercise and continuous passive movement (CPM) on24h,48h,72h after the TKA when the pain caused by exercise was mild or moderate (the score of VAS under8), time of first walk, walking distance daily, the number of daily walks, the time of the knee flexion angle to90°,the hospital stays after surgery and complications including failure of the nerve location, difficult catheter insertion, pain at the insertion site, infections or hematoma at the insertion site, inadvertent removal of the catheter and persistent motor or sensory deficit in order to assess the safety of different method for analgesia. We evaluated the patient satisfaction from the analgesic effect, knee function and the patients’comfort.Every aspect was assessed using a four-point scale.The total scale was12:very good(score=12),good(score=9),satisfactory(score=6),unsatisfactory(score=Results The VAS pain scores during rest, initiative exercise and CPM on4h,8h,12h,24h,36h,48h after the TKA in CFNB group were significantly lower than those in PCIA group (P<0.05). The VAS pain scores during rest, initiative exercise on the postoperative72h in CFNB group were lower than those in PCIA group but there was no significant difference between the two groups (P>0.05). The VAS pain scores during CPM on the postoperative72h in CFNB group were lower than those in PCIA group (P<0.05). The presses of the pump,the efficient presses and tramadol dose by intramuscular injection were fewer in CFNB group than those in PCIA group (P<0.05).Knee flexion angles when initiative exercise and CPM exercise on24h,48h,72h after the TKA when the pain caused by exercise was mild or moderate in CFNB group were significantly larger than those in PCIA group (P<0.05).The patients in CFNB group needed significantly less time for first work than that in PCIA group (P<0.05). The time of the knee flexion angle to90°and the hospital stays after surgery in CFNB group were shorter than those in PCIA group(P<0.05). No complication associated with CFBN was recorded. The side effects such as dizziness, nausea were fewer than those in PCIA group.CFNB group showed significantly greater satisfaction with their method of analgesia (9.8±1.0) than PCIA group (8.6±1.1)Conclusions The study group who received CFNB after TKA showed superior analgesia and higher patient satisfaction than those given PCIA. The CFNB was good for the functional rehabilitation after TKA. So CFNB can be recommended as an effective and safe method of analgesia after TKA.