Article

Ropivacaine infusion following high-volume local
infiltration analgesia has been shown to be effective after total knee
arthroplasty, but the optimum site of administration of ropivacaine has not been
evaluated. We compared the effects of intraarticular and extraarticular
adminstration of the local anesthetic for postoperative supplementation of
high-volume local infiltration analgesia. METHODS: In this
double-blind study, 36 rheumatic patients aged 51-78 years with physical status
ASA 2-3 who were scheduled for total knee arthroplasty were randomized into 2
groups. All patients received wound infiltration at the end of surgery with 300
mg ropivacaine, 30 mg ketorolac, and 0.5 mg epinephrine (total volume 156 mL). A
tunneled catheter was randomly placed either extraarticularly or
intraarticularly. Continuous infusion of ropivacain (0.5%, 2 mL/h) was started
immediately and was maintained during the next 48 h. Pain intensity at rest, on
movement, and with mobilization was estimated by the patients and the
physiotherapist; rescue morphine consumption was recorded. RESULTS: As estimated
by the patients, ropivacaine administered intraarticularly did not improve
analgesia relative to extraarticular infusion, but improved the first
mobilization. The incidence of high intensity of pain (VAS 7-10) was less in the
group with intraarticular infusion. Analgesic requirements were similar in the 2
groups (47 mg and 49 mg morphine). No complications of postoperative wound
healing were seen and there were no toxic side effects. INTERPRETATION:
Continuous infusion of ropivacaine intraarticulary did not improve postoperative
analgesia at rest relative to extraarticular administration, but it appeared to
reduce the incidence of high pain intensity during first exercises, and could
therefore be expected to improve mobilization up to 24 h after total knee
arthroplasty.

Langue : ANGLAIS