Total knee replacement: a comparison of ropivacaine and bupivacaine in combined femoral and sciatic block.
BACKGROUND
Femoral and sciatic nerve block may improve post-operative analgesia following total knee replacement.


OBJECTIVE
To compare the post-operative analgesia following primary total knee replacement provided by spinal anaesthesia alone or in combination with femoral and sciatic nerve block with bupivacaine or ropivacaine.


METHODS
Seventy-five patients were randomised into one of three groups: spinal anaesthesia only; spinal anaesthesia and combined femoral and sciatic nerve block with 1 mg x kg(-1) bupivacaine 7.5 mg x ml(-1) to each nerve; spinal anaesthesia and combined femoral and sciatic nerve block with 1 mg x kg(-1) ropivacaine 7.5 mg x ml(-1) to each nerve.


RESULTS
The mean (SD) time to first morphine request was significantly prolonged for both groups receiving combined femoral and sciatic block, 912 (489) min for the bupivacaine group and 781 (394) min for the ropivacaine group (P<0.001) compared with 413 (208) min for the group receiving spinal anaesthesia alone. Morphine consumption was significantly reduced in both groups receiving combined femoral and sciatic block. There were no systemic or neurological sequelae in any of the groups.


CONCLUSIONS
Femoral and sciatic blockade following intrathecal bupivacaine/diamorphine provided superior analgesia when compared with intrathecal bupivacaine/diamorphine alone. There were no significant clinical differences between the group receiving bupivacaine 7.5 mg x ml(-1) and the group receiving ropivacaine 7.5 mg x ml(-1).
McNamee
D A
DA
Department of Anaesthetics and Intensive Care Medicine, Queens University of Belfast, UK.
Convery
P N
PN
Milligan
K R
KR
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000577:Amides / Q000008:administration & dosage / Q000627:therapeutic use*; D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000627:therapeutic use; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000627:therapeutic use*; D002045:Bupivacaine / Q000008:administration & dosage / Q000627:therapeutic use*; D005260:Female; D005267:Femoral Nerve; D006801:Humans; D007278:Injections, Spinal; D008297:Male; D008875:Middle Aged; D009020:Morphine / Q000008:administration & dosage / Q000627:therapeutic use; D009407:Nerve Block; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy*; D000077212:Ropivacaine; D012584:Sciatic Nerve
D000577:Amides; D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D009020:Morphine; D000077212:Ropivacaine; D002045:Bupivacaine