Page 448 Acute Pain Management

Level III‐2). After topical application of capsaicin, the magnitude and duration of primary
hyperalgesia was similar on both older and younger subjects but secondary hyperalgesia
(tenderness) resolved more slowly in older people (Zheng et al, 2000 Level III‐2). The underlying
reason for these findings is again that the older person may have impaired descending
inhibitory mechanisms and a reduced capacity to down‐regulate after sensitisation leading to
prolonged recovery (Gagliese & Farrell, 2005).
Clinical implications
There are a number of clinical reports, summarised by Gibson (Gibson, 2003 Level IV; Gibson,
2006 Level IV) and Pickering (Pickering, 2005 Level IV), suggesting that pain symptoms and
presentation may change in the older patient; pain becomes a less frequent or less severe
symptom of a variety of acute medical conditions. Examples of differences in reports of acute
pain are commonly related to abdominal pain (eg associated with infection, peptic ulcer,
cholecystitis, or intestinal obstruction) or chest pain (eg myocardial ischaemia or infarction;
pneumonia) and are in general agreement with the experimental finding of increased pain
thresholds in the older person.
Compared with the younger adult with the same clinical condition, the older adult may report
less pain or atypical pain, report it later or report no pain at all. For example, in older patients,
right upper quadrant or epigastric pain associated with cholecystitis may be absent in 85%;
30% of those with peptic ulcer disease and up to 90% with pancreatitis may have no
abdominal pain; in those with advanced peritonitis pain may be a symptom in only 55%; and
reports of atypical pain or absence of pain occur in up to 33% of older patients with an acute
myocardial infarction and 50% with unstable angina (Pickering, 2005 Level IV).
Pain intensity after surgery may also be less. Older patients, matched for surgical procedure,
reported less pain in the postoperative period: pain intensity decreased by 10% to 20% each
decade after 60 years of age (Thomas et al, 1998 Level III‐2). Older men undergoing
prostatectomy reported less pain on a present pain intensity scale and McGill Pain
Questionnaire (but not a visual analogue scale [VAS]) in the immediate postoperative period
and used less PCA opioid than younger men undergoing the same procedure (Gagliese & Katz,
2003 Level III‐2). In a study of pain following placement of an IV cannula (a relatively
standardised pain stimulus), older patients reported significantly less pain than younger
patients (Li et al, 2001 Level IV).
11.2.3 Assessment of pain

CHAPTER 11 Even though cognitively impaired patients are just as likely as cognitively intact patients of the
Cognitive impairment
same age to have painful conditions and illnesses, the number of pain complaints and
reported pain intensity decrease with increasing cognitive impairment (Farrell et al, 1996; Herr et
al, 2006). Reasons for this could include a diminished memory, impairment of capacity to
report, or it could be that less pain is experienced (Farrell et al, 1996; Herr et al, 2006).
However, studies in patients with dementia suggest that they may not experience less pain.
Functional MRI responses following mechanical pressure stimulation showed no evidence of
diminished pain‐related activity in patients with Alzheimer’s disease compared with age‐
matched controls, indicating that pain perception and processing were not diminished in these
patients (Cole et al, 2006 Level III‐2).
Another study assessed the placebo component of analgesic therapies by looking at the effect
of both ‘overtly applied’ and ‘covertly applied’ local anaesthetic on pain after venipuncture in
patients with Alzheimer’s disease; those patients with reduced Frontal Assessment Battery

400 Acute Pain Management: Scientific Evidence