Efficacy of femoral triangle versus adductor canal approach to saphenous nerve block for postoperative analgesia in patients undergoing knee arthroplasty / 中华麻醉学杂志

ABSTRACT

Objective@#To compare the efficacy of femoral triangle versus adductor canal approach to saphenous nerve block for postoperative analgesia in the patients undergoing knee arthroplasty.@*Methods@#Sixty American Society of Anesthesiologists physical status Ⅰ or Ⅱ patients of both sexes, aged 53-68 yr, scheduled for elective total knee arthroplasty under general anesthesia, were assigned into 2 groups (n=30 each) using a random number table method: femoral triangle approach to saphenous nerve block group (group F) and adductor canal approach to saphenous nerve block group (group A). Femoral triangle and adductor canal approach to saphenous nerve block was performed by injecting 0.5% ropivacaine 20 ml in group F and group A, respectively.Patient-controlled saphenous nerve block analgesia was used in two groups, and the analgesic pump solution contained 1% ropivacaine 400 mg diluted to 160 ml in 0.9% sodium chloride injection.The analgesic pump was set up with a 5 ml bolus dose, a 30-min lockout interval and background infusion at a rate of 5 ml/h, and analgesia lasted until 72 h after operation.When visual analog scale score > 4 and pain was not relived after 30-min pressing by patients, pethidine hydrochloride 100 mg was intramuscularly injected as rescue analgesic.The muscle strength of quadriceps femoris was assessed by manual muscle test at 4, 8, 24, 48 and 72 h after operation.The patient′s satisfaction score was assessed and recorded at 72 h after operation.Rescue analgesia and development of adverse reactions (local anesthetic intoxication, itching, dizziness, urinary retention, nausea and vomiting) were recorded within 72 h after operation.@*Results@#Compared with group F, the muscle strength of quadriceps femoris was significantly increased at 4, 8 and 24 h after operation, the rate of postoperative rescue analgesia was decreased (P<0.05), and no significant change was found in patient′s satisfaction score or incidence of adverse reactions in group A (P>0.05).@*Conclusion@#Adductor canal approach to saphenous nerve block provides better efficacy for postoperative analgesia than femoral triangle approach to saphenous nerve block in the patients undergoing knee arthroplasty.