Page 407 Acute Pain Management

infusions of ropivacaine were effective and safe in neonates (Bosenberg et al, 2005 Level IV) and
children (Berde et al, 2008 Level IV) with minimal drug accumulation.
Epidural opioids alone have a limited role. Epidural morphine provided prolonged analgesia
but no improvement in the quality of analgesia compared with systemic opioids (Bozkurt et al,
2004 Level II). Epidural fentanyl alone was less effective than both levobupivacaine alone and
a combination of local anaesthetic and fentanyl (Lerman et al, 2003 Level II). Bolus doses of
epidural morphine were less effective than epidural infusions of fentanyl and local anaesthetic
(Kart, Walther‐Larsen et al, 1997 Level II; Reinoso‐Barbero et al, 2002 Level II). Ketoprofen improved
analgesia when given in conjunction with epidural sufentanil (Kokki et al, 1999 Level II).
A combination of local anaesthetic and opioid is frequently used in epidural infusions, but
there are limited data available to assess the relative merits of different regimens. Both
improvements in analgesia (Lovstad & Stoen, 2001 Level II) and no change (Lerman et al, 2003
Level II) have been shown with addition of fentanyl to local anaesthetic infusions. Addition of
fentanyl to bupivacaine or bupivacaine plus clonidine epidural infusions provided similar
analgesia but increased side effects (Cucchiaro et al, 2006 Level II). Addition of morphine to an
epidural local anaesthetic infusion was more effective than clonidine (Cucchiaro et al, 2003
Level II), but higher doses of clonidine improved analgesia when added to epidural ropivacaine
infusions (De Negri et al, 2001 Level II).
Outcomes
Perioperative regional analgesia modifies the stress response to surgery in children (Wolf et al,
1998 Level II; Humphreys et al, 2005 Level II). Suppression of the stress response may necessitate
a local anaesthetic block that is more intense or extensive than required for analgesia, and
therefore the risks of increased side effects or toxicity must be balanced against any potential
benefit (Wolf et al, 1998 Level II). Use of caudal opioids alone (morphine 30 mcg/kg) was less
effective than plain bupivacaine 0.25% in attenuating cortisol and glucose responses following
hypospadias surgery (Teyin et al, 2006 Level II).
Improvements in respiratory outcome with regional analgesia have not been established in
controlled comparative trials. Reductions in respiratory rate and oxygen saturation were less
marked during epidural analgesia compared with systemic opioids, but the degree of
difference was of limited clinical significance (Wolf & Hughes, 1993 Level II). Case series report
improvements in respiratory function and/or a reduced need for mechanical ventilation with
regional analgesia techniques (McNeely et al, 1997 Level IV; Hodgson et al, 2000 Level IV; Aspirot et
al, 2008 Level IV; Raghavan & Montgomerie, 2008 Level IV). A meta‐analysis of spinal versus general
anaesthesia for inguinal herniorrhaphy in premature infants reported a reduction in
postoperative apnoea in the spinal group (when infants having preoperative sedation were CHAPTER 10
excluded) and a reduced need for postoperative ventilation (of borderline statistical
significance) (Craven et al, 2003 Level I).
Epidural rather than systemic analgesia reduced hospital stay following fundoplication
(McNeely et al, 1997 Level IV) and ligation of patent ductus arteriosus in infants (Lin et al, 1999
Level IV).
Complications
Accidental intravascular injection remains the most life‐threatening complication of caudal
and epidural analgesia. As the sacrum is largely cartilaginous during infancy and early
childhood, there is an increased risk of injecting local anaesthetic into the highly vascular
medullary space of the sacrum (Veyckemans et al, 1992 Level IV). Sevoflurane attenuated
cardiovascular (CV) responses to adrenaline 0.5 mcg/kg less than halothane, and may be a
better agent to facilitate detection (Kozek‐Langenecker et al, 2000 Level III‐2). Almost all regional

Acute pain management: scientific evidence 359