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no difference in analgesia and no motor blockade reported in a PCEA comparison of
ropivacaine 0.05%, 0.075% and 0.1%, with fentanyl 4 mcg/mL and droperidol 25 mcg/mL
added to all solutions (Iijima et al, 2007 Level II). In another comparison of PCEA 0.625%
bupivacaine with fentanyl 3 mcg/mL and 0.15% ropivacaine alone, there was no difference in
pain relief; patient satisfaction was lower with PCEA ropivacaine even though it led to fewer
opioid‐related effects (Pitimana‐aree et al, 2005 Level II).
No studies directly compare fentanyl to morphine when added to local anaesthetic epidural
infusions, although a retrospective audit of the use of high thoracic epidural following cardiac
surgery suggested improved pain control and lowered infusion rate using ropivacaine 0.2%
with morphine 20 mcg/ml compared with fentanyl 2 mcg/ml (Royse et al, 2005 Level III‐3).
For information relating to the use of epidural local anaesthetics or opioid/local anaesthetic
combinations for labour pain see Section 11.1.2.
Peripheral local anaesthetics
A number of studies have compared different local anaesthetics or doses of local anaesthetics
used for continuous peripheral nerve blockade (CPNB).
At concentrations of 0.5% or greater, there were no significant differences in onset time and
intensity or duration of sensory blockade between bupivacaine, levobupivacaine or
ropivacaine in sciatic (Casati et al, 2002 Level II), interscalene (Casati, Borghi et al, 2003 Level II) or
axillary brachial plexus blocks (McGlade et al, 1998 Level II). The intensity and duration of motor
block is frequently less with ropivacaine compared with bupivacaine or levobupivacaine, but
this has little effect on the quality of block for surgery (McGlade et al, 1998 Level II; Casati, Borghi
et al, 2003 Level II).
A comparison of three concentrations (0.1%, 0.2%, 0.3%) of ropivacaine for continuous CHAPTER 5
femoral nerve blockade following total knee arthroplasty found that infusions of 0.2% and
0.3% ropivacaine had equivalent quality of postoperative analgesia (Brodner et al, 2007 Level II).
After similar surgery, there was no difference in pain relief or motor block between patient‐
controlled femoral nerve blockade with 0.125% levobupivacaine and 0.2% ropivacaine (Heid et
al, 2008 Level II).
Comparisons of two different patient‐controlled CPNB regimens found different results
depending on the location of the block; the regimens were ropivacaine at 4 mL/hr 0.4% (bolus
2 mL) or 8 mL/hr 0.2% (bolus 4 mL). For continuous popliteal nerve blockade, the larger
volumes of the dilute local anaesthetic were more likely to cause an insensate limb (Ilfeld et al,
2008 Level II); for continuous interscalene nerve block there was no difference between the
two solutions (Le et al, 2008 Level II), and for continuous infraclavicular nerve block the smaller
volumes of the more concentrated local anaesthetic were more likely to cause an insensate
limb (Ilfeld et al, 2009 Level II).
Another comparison of patient‐controlled continuous interscalene blockade using 0.25%
levobupivacaine, 0.25% ropivacaine and 0.4% ropivacaine reported less effective pain relief
with the lower concentration of ropivacaine (Borghi et al, 2006 Level II).
Continuous popliteal sciatic nerve blockade using 0.2% ropivacaine, 0.2% levobupivacaine and
0.125% levobupivacaine resulted in similar pain relief after foot surgery, but fewer patients
had complete recovery of motor function at 24 and 48 hours with 0.2% levobupivacaine (Casati
et al, 2004 Level II).

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