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DeGaetano, 2006; Basu et al, 2007; Ludlow et al, 2007; Macintyre & Schug, 2007; Roberts, 2008).
However, evidence for the most appropriate management in these patients is very limited and
the advice given in these papers remains based primarily on case series, case reports, expert
opinion and personal experience.
In general, management of these patients should focus on:
• effective analgesia;
• use of strategies that may help to attenuate tolerance or OIH;
• prevention of withdrawal; and
• close liaison with other treating clinicians and specialist teams as required and
appropriate discharge planning.
Effective analgesia
It is known that opioid requirements are usually significantly higher in opioid‐tolerant
compared with opioid‐naive patients and that the interpatient variation in the doses needed is
even greater. After a variety of surgical procedures, opioid‐tolerant patients using PCA (Rapp et
al, 1995 Level III‐2) or epidural analgesia (de Leon‐Casasola et al, 1993 Level III‐2) required
approximately three times the dose than their opioid‐naive counterparts. Opioid‐tolerant
patients with chronic pain also reported higher pain scores after surgery and their pain
resolved more slowly compared with opioid‐naive patients (Chapman et al, 2009 Level III‐2).
Opioid‐tolerant patients reported higher pain scores (both resting and dynamic) and remained
under the care of APSs longer than other patients (Rapp et al, 1995 Level III‐2). Compared with
opioid‐tolerant patients with cancer pain, opioid‐tolerant patients with non‐cancer pain had
higher rest and dynamic pain scores and required longer APS input, but there was no
difference in opioid requirements (Rapp et al, 1995 Level III‐2). In addition, staff relied more on
functional measures of pain than on pain scores to assess pain intensity in these patients (Rapp
et al, 1994 Level IV).
The incidence of opioid‐induced nausea and vomiting may be lower in opioid‐tolerant patients
although the risk of excessive sedation/ respiratory depression may be higher (Rapp et al, 1995
Level III‐2). An explanation to the patient of why good pain relief with opioids may be more
difficult to obtain and why the dose that can safely be given will be limited by any onset of
excessive sedation may be appropriate.
IV PCA is a useful modality for pain relief in opioid‐tolerant patients, including those with an
addiction disorder, provided that pain intensity and opioid consumption are carefully
CHAPTER 11 opioid; larger bolus doses will often be needed (Mitra & Sinatra, 2004; Macintyre & Schug, 2007).
monitored and background requirements are provided if the patient cannot take their usual
The size of an appropriate dose (on an individual patient basis) has been calculated by one
group of investigators by using a preoperative fentanyl infusion until the patient’s respiratory
rate was lower than 5/minute; pharmacokinetic simulations were then used to predict the size
of the PCA bolus dose and the rate of a background infusion that would be required for
postoperative analgesia (Davis et al, 2005 Level IV). It may also be based on the dose of opioid
the patient is already taking (Hadi et al, 2006; Macintyre & Schug, 2007). Regardless of the initial
dose prescribed, subsequent doses will need to be titrated to effect for each patient.
Neuraxial opioids have been used effectively in opioid‐tolerant patients; although higher doses
may be required and may not result in an increase in adverse effects (de Leon‐Casasola et al,
1993 Level III‐2). Effective analgesia using intrathecal or epidural opioids will not necessarily
prevent symptoms of opioid withdrawal (Carroll et al, 2004).

424 Acute Pain Management: Scientific Evidence