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Adjuvant drugs
The efficacy of adding of adjuvant drugs such as adrenaline (epinephrine), clonidine, ketamine,
midazolam, neostigmine and magnesium to solutions used for epidural analgesia has also
been investigated (see Section 5.3).
7.2.3 Patient-controlled epidural analgesia
The use of patient‐controlled epidural analgesia (PCEA) has become increasingly popular;
it is based on similar concepts as for other patient‐controlled techniques.
Comparison with continuous epidural infusions
A meta‐analysis comparing PCEA, continuous epidural infusions and IV PCA opioids after
surgery showed that both forms of epidural analgesia (with the exception of hydrophilic
opioid‐only epidural regimens) provided better pain relief with rest and with activity than PCA
opioids, but that analgesia with a continuous epidural infusion was superior to PCEA, although
the incidence of nausea, vomiting and motor block was higher (Wu et al, 2005 Level I).
However, results from other more recent studies are conflicting. In a large study looking
specifically at patients after colonic resection, PCEA was superior to continuous epidural
infusion with regard to pain control, requirements for top‐ups and systemic analgesia as well
as patient satisfaction (Nightingale et al, 2007 Level II). In contrast, comparisons of PCEA and
continuous epidural infusions for pain relief after thoracotomy using both high (5 mg/mL) and
low (1.5 mg/mL) concentrations of levobupivacaine showed no differences in quality of
analgesia, morphine consumption or satisfaction; more patients in the high concentration
continuous epidural infusion group had significant motor blockade (Dernedde et al, 2006
Level II).
For pain relief during labour, a comparison of demand dose‐only PCEA, PCEA with a
continuous infusion, and a continuous epidural infusion only during labour, showed that
dose‐only PCEA resulted in less total epidural dose compared with the other modalities;
no differences were noted with respect to pain scores, motor block, duration of labour, CHAPTER 7
number of staff interventions, delivery outcome, and maternal satisfaction score (Vallejo et al,
2007 Level II).
Concurrent background (continuous) infusions
The addition of a continuous background infusion to PCEA using bupivacaine and fentanyl
following gastrectomy resulted in significantly better dynamic pain scores, higher total doses
and a greater incidence of pruritus than PCEA‐bolus dose only (Komatsu et al, 1998 Level II).
The use of a night‐time‐only infusion with PCEA bupivacaine‐fentanyl, also in postgastrectomy
patients, resulted in better sleep, but total cumulative doses were similar and pain scores
were only better in the morning of the second postoperative day (Komatsu et al, 2001 Level II).
However, pain relief is not always improved. After lower abdominal surgery there was no
difference in pain scores, but higher total cumulative doses and incidence of side effects when
a background infusion was added to PCEA with ropivacaine and fentanyl (Wong et al, 2000
Level II). The addition of a background infusion to bupivacaine‐fentanyl PCEA did not improve
pain relief after pelvic reconstruction (Nolan et al, 1992 Level II).
In a systematic review of PCEA in labour analgesia, the use of a continuous background
epidural infusion combined with PCEA resulted in improved maternal analgesia and reduced
unscheduled clinician interventions (Halpern & Carvalho 2009, Level I).
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