OS_1310_part2_Layout 1 10/7/13 10:26 AM Page 64
R E G I O N A L
A N E S T H E S I A
mined rates +/- bolus settings. Ropivacaine has become commonplace in
this setting due to a favorable safety profile and the propensity for analgesia with reduced motor involvement.
The choice of local anesthetic for initial injection is considerably
more varied and largely depends on practice environment. Some
staff at our institution use 2% lidocaine with epinephrine, which
allows for rapid confirmation of a successful primary block and
subsequent evaluation of analgesia with the catheter infusion
alone. This approach can lessen overall catheter failures, but
assumes you have the time, manpower, desire and expertise to
replace suboptimal catheters. Using longer-acting local anesthetics
such as 0.5% ropivicaine (Marcaine) limits evaluation of the
catheter infusion before PACU discharge, but several of our staff
recommend it in settings where catheter replacement is impractical. The emphasis here is on getting a good primary block for the
first 16 to 24 hours (when analgesic requirements are the highest),
and then hoping catheter placement is sufficient to maintain some
degree of analgesia afterwards.
5. Know where your catheter rests
Considerable variability exists regarding CPNB placement techniques. Many use nerve stimulation while others prefer ultrasound,
or even a combination of both. We can debate the efficacy of an
individual style, but user familiarity ultimately determines a physician's success. Due to visual confirmation, patient comfort and a
theoretical increase in safety, our preference is ultrasound.
Ultrasound aids needle positioning, and affords continuous visualization during catheter placement and local anesthetic injection.
When ultrasound is unavailable and we are using nerve stimulation,
we always try to obtain stimulation with less than 0.5 milliamps.
6 4
O U T PAT I E N T S U R G E R Y M A G A Z I N E O N L I N E | O C T O B E R 2013
