Femoral nerve block for patient undergoing total knee arthroplasty: Prospective, randomized, double-blinded study evaluating analgesic effect of perineural fentanyl additive to local anesthetics.
BACKGROUND
The existence of peripheral opioid receptors and its effectiveness in peripheral nerve block remain controversial. The aim of this prospective, randomized, double-blinded study was to examine the analgesic effects of adding fentanyl to ropivacaine for continuous femoral nerve block (CFNB) using patient-controlled analgesia after total knee arthroplasty (TKA).


METHODS
The patients were divided into 2 groups, each with n = 40 in ropivacaine (R) group and n = 42 in R with fentanyl (R + F) group. After operation, the patients in each group received R + F and R alone via a femoral nerve catheter, respectively. We assessed the visual analog scale (VAS) pain immediately before administration (baseline) and at 15, 30, and 60 minutes on postanesthesia care unit (PACU), and resting and ambulatory VAS score up to 24 hours.


RESULTS
Overall, the average VAS scores in the R + F group were slightly lower than those of the R group. However, the VAS score differences between groups were not statistically significant, except for 30 minutes (P = 0.009) in PACU. R group showed higher supplemental analgesics consumption in average compared with R + F group, but not significant.


CONCLUSIONS
Additional fentanyl did not show prominent enhancement of analgesic effect in the field of CFNB after TKA.
Department of Anesthesiology and Pain Medicine, Chonnam National University, Medical School, Gwangju, Republic of Korea.
Bong Ha
BH
Heo
Hyeon Jung
HJ
Lee
Hyung Gon
HG
Lee
Man Young
MY
Kim
Keun Suk
KS
Park
Jeong Il
JI
Choi
Myung Ha
MH
Yoon
Woong Mo
WM
Kim
D000368:Aged; D000577:Amides; D016058:Analgesia, Patient-Controlled; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D000779:Anesthetics, Local; D019645:Arthroplasty, Replacement, Knee; D004311:Double-Blind Method; D005260:Female; D005267:Femoral Nerve; D005283:Fentanyl / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000517:prevention & control*; D011446:Prospective Studies; D000077212:Ropivacaine
D000577:Amides; D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D000077212:Ropivacaine; D005283:Fentanyl