Clinical value of nerve stimulator-versus ultrasound-guided continuous femoral nerve block for analgesia after laparoscopic surgery

Abstract

Objective To compare the clinical value of nerve stimulator-versus ultrasound-guided continuous femoral nerve block for analgesia after laparoscopic surgery.Methods Forty patients,aged 18-60 yr,with body mass index of 18-30 kg/m2,of ASA physical status Ⅰ or Ⅱ,scheduled for elective laparoscopic surgery,were randomly assigned into 2 groups (n =20 each) using a random number table:nerve stimulator group (group S) and ultrasound group (group U).Epidural anesthesia was performed with 1.73 ％ carbonated lidocaine in both groups.0.2％ ropivacaine 5 ml/h was infused continuously after surgery to perform femoral nerve block for analgesia.VAS score at rest was assessed at 2,6,24 and 48 h after surgery.At 24 and 48 h after surgery,VAS scores during active and passive movement were assessed.The time for catheter placement near the femoral nerve and development of subcutaneous hematoma at the puncture site,local anesthetic intoxication and nausea and vomiting were recorded.The postoperative requirement for analgesics was also recorded.Results There was no significant difference in the VAS scores and puncture for femoral nerve block-and local anesthetics-related adverse events between the two groups.The time for catheter placement near the femoral nerve was 8.0 ± 1.4 and (6.7 ± 0.9) min in S and U groups,respectively,and the time was significantly longer in group S than in group U.No patients required rescue analgesic after surgery in both groups.Conclusion Nerve stimulator-guided continuous femoral nerve block provides higher clinical value than ultrasound-guided continuous femoral nerve block for analgesia after laparoscopic surgery and it is more suitable for clinical application. Key words: Physical stimulation ; Ultrasonography ; Femoral nerve; Nerve block ; Pain,postoperative; Analgesia; Arthroscopy