A comparison of 0.5% ropivacaine and 1% mepivacaine for sciatic nerve block in the popliteal fossa.
BACKGROUND
The purpose of this study was to compare anesthetic efficacy and postoperative analgesia of 0.5% ropivacaine and 1% mepivacaine for sciatic nerve block in the popliteal fossa (popliteal block).


METHODS
A prospective, double-blind study was carried out in 58 adult patients scheduled for outpatient foot or ankle surgery. They were randomized to receive popliteal block with 40 ml of either 0.5% ropivacaine (group R) or 1% mepivacaine (group M). An atraumatic, Teflon-coated needle connected to a neurostimulator was used to make a single puncture using a posterior approach. The times to onset of sensory and motor block, and the need for intraoperative sedation were recorded. Before discharge, patients were asked to document the time to first analgesic use, time to return of full sensation in the foot, and their evaluation of the technique.


RESULTS
Onset time (mean+/-standard deviation, 95% confidence interval) of both sensory block (6.5+/-5.1 min, 4.47-8.49, in group R and 6.2+/-3.7 min, 4.83-7.69, in group M) and motor block (6.6+/-4.4 min, 4.81-8.23, in group R and 7.9+/-4.1 min, 6.29-9.53, in group M) was similar in both groups. Postoperative analgesia lasted longer in group R (15.2+/-5.1 h, 13.25-17.21) than in group M (5.7+/-1.8 h, 5.01-6.41; P<0.001). Duration of sensory block was longer in group R (20.7+/-6.2 h, 18.51-23.01) than in group M (6.5+/-1.7 h, 5.86-7.16; P<0.001). Acceptance of the anesthetic procedure was similar in both groups.


CONCLUSIONS
In this study we demonstrated that both 0.5% ropivacaine and 1% mepivacaine for popliteal block produced rapid, effective and safe anesthesia but postoperative analgesia was more long-lasting with ropivacaine.
Fernández-Guisasola
J
J
Department of Anesthesiology and Critical Care, Anesthesia Unit, Fundación Hospital Alcorcón, Alcorcón, Madrid, Spain. jfguisasola@fhalcorcon.es
Andueza
A
A
Burgos
E
E
Plaza
A
A
Porras
M C
MC
Reboto
P
P
Rivera
J C
JC
del Valle
S G
SG
D000328:Adult; D000368:Aged; D000577:Amides / Q000494:pharmacology*; D000842:Ankle / Q000601:surgery*; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008297:Male; D008619:Mepivacaine / Q000494:pharmacology*; D008875:Middle Aged; D009407:Nerve Block; D011446:Prospective Studies; D000077212:Ropivacaine; D012584:Sciatic Nerve
D000577:Amides; D000077212:Ropivacaine; D008619:Mepivacaine