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scores (a measure of frontal executive function) had a reduced placebo component to their
pain relief and dose increases were required to produce adequate analgesia (Benedetti et al,
2006 Level III‐2).
Undertreatment of acute pain is more likely to occur in cognitively impaired patients (Feldt et
al, 1998 Level III‐2; Forster et al, 2000 Level III‐2; Morrison & Siu, 2000 Level III‐2).
A common form of acute cognitive impairment in the older patient is delirium or confusion,
which is associated with increased postoperative morbidity, impaired postoperative
rehabilitation and prolonged hospital stays (Bekker & Weeks, 2003; Bitsch et al, 2006; Fong et al,
2006; Greene et al, 2009 Level III‐3). Delirium is more common during acute illnesses in the older
person and occurs in up to 80% of older postoperative patients, depending on the type of
surgery. A systematic review confirmed that postoperative cognitive dysfunction (POCD) is
relatively common after non‐cardiac surgery and that the older patient is particularly at risk
(Newman et al, 2007 Level I).
Risk factors associated with the development of delirium include old age, infection, pre‐
existing dementia, pre‐existing depression, hypoxaemia and reduced cerebral oxygen
saturation, anaemia, drug withdrawal (eg alcohol, benzodiazepines), fluid and electrolyte
imbalance, unrelieved pain and some drugs — for example, those with central anticholinergic
activity (eg atropine, tricyclic antidepressants, major tranquilizers, some antiemetics),
benzodiazepines, opioids, ketamine, oral hypoglycaemics, NSAIDs and anticonvulsants
(Aakerlund & Rosenberg, 1994; Moore & O'Keeffe, 1999; Morrison et al, 2003 Level III‐2; Alagiakrishnan
& Wiens, 2004; Bitsch et al, 2006; Fong et al, 2006; Vaurio et al, 2006; Casati et al, 2007; Greene et al,
2009; Morimoto et al, 2009). While delirium is associated with early postoperative cognitive
dysfunction, it may not have a long‐term effect (Rudolph et al, 2008 Level IV).
Measurement of pain
Patient self‐report measures of pain
Unidimensional measures of pain intensity (see Section 2) are more commonly used to
quantify pain in the acute pain setting than multidimensional measures. Unidimensional
measures used in younger adult populations, and which have been shown to be appropriate
for use in the older patient, include the verbal numerical rating scale (VNRS), Faces Pain Scales,
verbal descriptor scale (VDS) and the numerical rating scale (NRS; a calibrated VAS), with more
equivocal support for use of the VAS.
In a comparison of five pain scales — VAS, VNRS, NRS, VDS and FPS — in an experimental
setting, all the scales could effectively discriminate different levels of pain sensation in older
people. However the VDS was the most sensitive and reliable and considered to be the best
choice in the older adult, including those with mild‐to‐moderate cognitive impairment,
although it ranked second to the NRS for patient preference (Herr et al, 2004 Level III‐2). CHAPTER 11
In a comparison of VAS, VDS and NRS, in younger and older patients using PCA after surgery,
the NRS was also the preferred pain scale in both patient groups, with high reliability and
validity, although the VDS also had a favourable and similar profile; use of the VAS in the older
patients resulted in high rates of unscorable data and low validity (Gagliese et al, 2005
Level III‐2).
Similarly, after a comparison of the Faces Pain Scale and Red Wedge Scale (RWS) in older
patients (65 years or older) after cardiac surgery, when VAS and VDS were also measured in
each patient, the VDS was shown to be the most reliable, followed by the RWS; the VAS was
the least suitable (Pesonen et al, 2008 Level III‐1). Using the same comparisons in patients aged
76 to 96 years with non‐surgical pain that included an acute component, it was shown that
those with normal cognitive function were able to use all fours scales well, while only the VDS

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