The average age of the world’s population is increasing rapidly. Elderly can be divided into “young old” (age 65-80 years old) and “older old” (greater than 80 years of age). Advances in anaesthesia and surgery have led to increasing number of elderly patients undergoing more major surgery. Management of postoperative pain in these patients can be complicated by age-related and disease-related changes in physiology. Alterations in pharmacokinetics and pharmacodynamics may influence drugs and techniques used for pain relief. Under-treatment of pain in the elderly is widespread ASA section VI, p 255. Under-treatment of acute pain is more likely to occur in elderly patients who are cognitively impaired. ANZCA chapter 11.2, p 396.

Condition specific perioperative analgesic issues

• Diminished functional status
• Co-morbid diseases and concurrent medications
• Problems with pain assessment due to cognitive impairment and communication difficulties
• Sensitivity to centrally acting anticholonergic agents, opioids and antihistamines
• Age-related differences in pain perception

Evidence-based recommendations specific to the condition

Assessment of pain

In general, cognitively intact older patients can manage most commonly used uni-dimensional pain scales. Reliability, validity and patient preference is good with numeric rating scales (NRS) and verbal descriptor scales (VDS) using familiar words such as none, slight, mild, moderate and severe. The Faces Pain Scale is also a reliable measure ANZCA chapter 11.2.3, p 401. Extensive and proactive evaluation and questioning may be necessary to overcome barriers that hinder communication regarding unrelieved pain. ASA, section VI, page 255

Drugs used in management of postoperative pain

In general there is limited evidence since elderly patients are excluded from clinical trials because of advanced age, co-morbidities and concurrent medications.

Paracetamol: Unless contraindicated all patients should receive around-the-clock paracetamol as part of analgesic treatment ASA section IV, p255. It should not be administered i.v. once the oral route can be used French p406. In the absence of significant renal impairment, routine dose reductions are not necessary ANZCA Chapter 11.2.4, p402. Paracetamol is the preferred non-opioid for use in elderly patients ANZCA Chapter 11, ‘Key messages’, p 407.

NSAID’s: Conventional and selective NSAID’s (Coxibs) should be used very cautiously in older patients..Older patients are more likely to suffer adverse gastric and renal side effects following administration of non-selective NSAID’s and may also be more likely to develop cognitive dysfunction. The risk of other adverse effects, including effects on renal function and exacerbation of cardiac failure are similar in both types of NSAID’s. ANZCA chapter 11.2.4, p 402-403.

Opioids: Older patients require less opioid than younger patients to achieve the same degree of pain relief. Age-related 2-to 4-fold decrease in morphine and fentanyl requirements have been reported. The decrease in opioid requirements is related more to changes in pharmaco­dynamics that accompany aging rather than changes in pharmacokinetics. However, a large inter-patient variability exists and doses must be titrated to effect ANZCA chapter 11.2.4, p 403; ASA guidelines p255. Nevertheless, the titrated dose should be reduced in patients over 85 years, in patients with impaired renal or hepatic function. PCA is not contraindicated in the elderly subject French section 5.4, p405.

In patients over 75 years, elimination half-life of tramadol may be slightly prolonged. Lower daily doses have been recommended. ANZCA chapter 11.2.4., p403. Codeine may be effective for weak or moderate pain. However, its efficacy and tolerability is unpredictable mainly because of genetic variability. Dextroproxyphen should not be used in elderly patients. French section 5.4., p 405.

Regional analgesia techniques: Older patients are more sensitive to the effects of localanaesthetics. Age-related decreases in clearance of bupivacaine and ropivacaine have been shown. In general, epidural analgesia can provide the most effective pain relief of all analgesic therapies in the postoperative setting. Older patients are more likely to have ischemic heart disease, a high thoracic epidural can improve left ventricular function and myocardial oxygen availability. Age is also a determinant of the spread of local anaesthetic in the epidural space and the degree of motor blockade. Older patients may be more susceptible to some of the adverse effects of epidural analgesia, including hypotension. Intrathecal morphine in doses of 100-200 mcg is effective in the elderly after hip and knee arthroplasty and thoracotomy ANZCA chapter 11.2.7, p 406. Other regional techniques include femoral blocks after major lower limb surgery. In general all perineural techniques provide highly effective analgesia for the elderly and non-elderly patient population. Appropriate blocks exist for a large variety of surgical procedures and are recommended. Wound infiltration techniques with or without catheters are also recommended as effective and safe in a large variety of inpatient and ambulatory surgical procedures. ANZCA chapter 11.2.8, p 406-407.

Condition specific issues related to nursing / monitoring patients

Titration of medications should be vigilant to ensure adequate treatment while avoiding adverse effects that such as somnolence, in this vulnerable group of patients, often taking other medications. ASA section vi, p 255.

Summary

When treating postoperative pain in elderly patients, extensive and proactive evaluation and questioning may be necessary to overcome barriers that hinder communication regarding un-relieved pain. Multimodal pain management therapy should be employed whenever possible, including regional blockade with local anaesthetics, non-opioid analgesia. Choice of medication, dose and duration of therapy should be individualised.

Supplementary reading

1. Aubrun F, Gazon M, Schoeffler M, Benyoub K. Evaluation of perioperative risk in elderly patients. Minerva Anestesiol. 2012 May;78(5):605-18.
2. Falzone E, Hoffmann C, Keita H. Postoperative analgesia in elderly patients. Drugs Aging. 2013 Feb;30(2):81-90.
3. White PF, White LM, Monk T, Jakobsson J, Raeder J, Mulroy MF, Bertini L, Torri G, Solca M, Pittoni G, Bettelli G. Perioperative care for the older outpatient undergoing ambulatory surgery. Anesth Analg 2012;114:1190-1215