Page 248 Acute Pain Management

variables that hinder analysis included the pre‐existing degree of inflammation, type of
surgery, the baseline pain severity and the overall relatively weak clinical effect (Gupta et al,
2001 Level I). When published trials were analysed taking these confounding factors into
consideration, including the intensity of early postoperative pain, the data did not support an
analgesic effect for intra‐articular morphine following arthroscopy compared with placebo
(Rosseland, 2005 Level I).

Note: reversal of conclusions
This reverses the Level 1 conclusion in the previous edition of this
document; the earlier meta‐analyses performed without taking
confounding factors into consideration had reported improved
pain relief with intra‐articular morphine.

7.5.3 Wound infiltration including wound catheters

A meta‐analysis reviewed outcomes following postoperative analgesia using continuous local
anaesthetic wound infusions (Liu et al, 2006 Level I). Analyses were performed for all surgical
groups combined and for the four subgroups (cardiothoracic, general, gynaecology‐urology
and orthopaedics). While there were some minor variations between the subgroups, the
results overall (ie for all surgical groups combined) showed that this technique led to
reductions in pain scores (at rest and with activity), opioid consumption, PONV and length of
hospital stay; patient satisfaction was higher and there was no difference in the incidence of
wound infections (Liu et al, 2006 Level I).
Continuous infusion of ropivacaine into the wound after appendicectomy was superior to
a saline infusion (Ansaloni et al, 2007 Level II) as was a continuous wound infusion of bupivacaine
after open nephrectomy (Forastiere et al, 2008 Level II). Infusion of ropivacaine into the site
CHAPTER 7 of iliac crest bone graft harvest resulted in better pain relief in the postoperative period

compared with IV PCA alone and significantly less pain in the iliac crest during movement
at 3 months (Blumenthal et al, 2005 Level II).
Continuous infusion of bupivacaine below the superficial abdominal fascia resulted in more
effective analgesia than an infusion sited above the fascia after abdominal hysterectomy
(Hafizoglu et al, 2008 Level II).
Continuous wound infusion of diclofenac after Caesarean section was as effective as a
ropivacaine infusion with systemic diclofenac (Lavand'homme et al, 2007 Level II).
Early postoperative abdominal pain was improved after laparoscopic cholecystectomy by the
use of intraperitoneal local anaesthetic; the effect was better when given at the start of the
operation compared with instillation at the end of surgery (Boddy et al, 2006 Level I). There
were no differences in pain relief found between systemic pethidine and intraperitoneal
administration of pethidine and ropivacaine, alone or in combination (Paech et al, 2008 Level II).
Preperitoneal infusion of ropivacaine after colorectal surgery resulted in improved pain relief,
opioid‐sparing and earlier recovery of bowel function (Beaussier et al, 2007 Level II).

7.5.4 Topical application of local anaesthetics

Topical EMLA® cream (eutectic mixture of lignocaine and prilocaine) was effective in reducing
the pain associated with venous ulcer debridement (Briggs & Nelson, 2003 Level I). When
compared with EMLA® cream, topical amethocaine provided superior analgesia for superficial
procedures in children, especially IV cannulation. (Lander et al, 2006 Level I).

200 Acute Pain Management: Scientific Evidence