May L. Chin, MD
Associate Professor of Anesthesiology
George Washington University Medical Center
901 23rd Street NW
Washington, DC 20037
anemlc@gwumc.edu

Introduction:

Poorly controlled pain in the postoperative period can lead to slow recovery and life threatening complications. Meeting the needs of an elderly patient can be especially challenging. Elderly patients often have multi-system disease in conjunction with physiologic changes associated with aging. Not infrequently, mental impairment and polypharmacy render these patients susceptible to adverse effects of analgesic medications used in pain control.

Some of the problems encountered in caring for the elderly include:

1)Misconceptions

-pain perception decreases with age
-elderly cannot tolerate opioids

2)Inadequate assessment

-difficult in patients with cognitive impairment, dementia, aphasia

3)Lack of education

-fear of addiction (patient, health care giver)
-patient expects to have pain
-patient unfamiliar/unwilling to use equipment, e.g. PCA

Ways to optimize pain control:

Assessment

• Frequent assessment, especially after interventions for pain control.
  Questions: What is the level of pain?
  How much relief from previous dose?
  What activities? Able to deep breathe?
  Any side effects?

Frail, debilitated patients and cognitively impaired patients benefit from frequent assessments. Enlist the help of a family member in order to try and "understand" the patient. It may be helpful to note the patient's posture (rigid, not moving), facial expressions, verbal cues such as moaning. In a confused patient (who is previously not confused) rule out hypoxia, drug interaction, night time confusion, and pain. A history of alcohol abuse warrants preventive measures against withdrawal.

Education

Educating the patient, the patient's family in commonly held misconceptions such as addiction to opioids used in acute pain. Patients should be encouraged and instructed to use equipment,
e.g. epidural or intravenous PCA.

What are the analgesic options for pain control?

Pharmacologic options

In the elderly patient changes in drug absorption, distribution, metabolism and elimination may affect the eventual plasma level and effect of a given analgesic drug. Drug absorption may be altered as a result of increased gastric pH and decreased gastric motility. Distribution of drugs may change due to a decrease in lean body mass or to a decrease in plasma proteins and albumin from chronic illness and poor nutrition. Hepatic blood flow, renal blood flow and glomerular filtration rate are decreased in the elderly. Consequently, hepatic drug metabolism may be decreased and elimination of drugs may change as renal and hepatic clearance decreases.

The oral route of analgesic drug administration is simple and cost effective. Non steroidal anti inflammatory agents and opioid analgesics are prescribed for patients who experience mild to moderate pain and can take oral medications postoperatively.

Acetaminophen:

-oral analgesic, antipyretic
-dose around the clock
-do not exceed total daily dose of 4 grams
-hepatotoxicity a concern
-opioid sparing

NSAIDS:

-use those with short half lives (e.g. ibuprofen, ketoprofen, diclofenac - oral route)
-parenteral NSAID Ketorolac (use 15mg IV q6 hr, not to exceed 5 days)
-dose around the clock
-opioid sparing effect
-beware of gastrointestinal, renal, platelet effects

NSAID toxicity:

Gastrointestinal

-risk of bleed with high dose, long duration, concurrent steroid use, prior ulcer
-least risk with ibuprofen, diclofenac
-intermediate risk with indomethacin, naproxen, piroxicam
-highest risk with ketoprofen, azapropazone
-non acetylated salicylates well tolerated Renal
-avoid NSAID in patients with renal failure, insufficiency, CHF, shock
-chronic progressive renal failure with long term use, high dose Platelets
-NSAIDs inhibit platelet aggregation (reversible)
-non acetylated salicylates less of an effect

Opioids:

-use those with short half lives (morphine, hydromorphone, oxymorphone, oxycodone)
-do not use meperidine as first line opioid. Normeperidine metabolite relies on renal elimination, accumulation is CNS toxic.
-avoid IM administration (painful, unpredictable absorption due to less muscle, more fat)
-side effects, decrease dose if adequate analgesia
-patient monitoring for sedation, respiratory depression

-use around the clock dosing
-start with low dose (25% to 50% of usual adult dose), titrate up slowly
-use adjuncts (acetaminophen or NSAID) for opioid sparing effect
-patient monitoring for sedation, respiratory depression

Other routes of administration of analgesics include parenteral, epidural or intrathecal. Transderm opioid (fentanyl) is not easily titratable and is not appropriate (contraindicated in elderly) for use in acute postoperative pain. Local anesthetics are useful in wound infiltration; regional blocks (e.g. brachial plexus block) for prolonged postoperative analgesia; and in low concentrations in epidural analgesia.

Intramuscular injections are suboptimal; muscle wasting may be present in the elderly patient and may contribute to unpredictable levels of analgesic drug.

IV PCA Opioid Use

-instruct patient on concept and use of machine
-patient should be physically able to push the button
-designate family member or nurse to activate button if patient unable
-use basal rate with caution

Epidural Analgesia with Opioids

-decrease dose of opioid, especially morphine sulphate
-decrease concomitant parenteral opioid administration
-patient monitoring for sedation, respiratory depression

Common side effects of opioids:

-respiratory depression, sedation
-nausea, vomiting
-ileus
-pruritus
-urinary retention

Less common side effects

-confusion, psychosis
-dizziness, orthostatic hypotension

Non pharmacologic options

These can be helpful to the following patients: those with anticipated prolonged postoperative recovery; patients who have a high level of anxiety or fear; those who may have to undergo treatments during their recovery (eg cancer patients); and those patients who continue to have discomfort despite pharmacological interventions and wish to avoid adverse effects of increasing doses of analgesic drugs.

Physical agents include heat or cold; massage, exercise; transcutaneous electrical nerve stimulation (TENS). Cognitive-behavioral techniques include education/instruction, relaxation, imagery, music, biofeedback

Conclusion:

The elderly patient often presents with multisystem disease and changes in drug metabolism, elimination leading to increased sensitivity to analgesic medications. Even so, it is possible to provide these patients with good pain control by selecting the analgesic modality and drugs best suited to each individual patient. Using careful titration of analgesic doses, and by assessing patients frequently for inadequate pain control and for adverse side effects, elderly patients need not be denied the benefits of modern technology in the management of acute pain.

Goals of optimized pain management in the postoperative period are to provide patient comfort and satisfaction, to restore function, to decrease perioperative morbidity, and thereby decrease hospital stay and health care costs.

References:

1. Pain in the Elderly, Ferrell BR, Ferrell BA, eds.; IASP Press, Seattle, 1996
2. Chin ML. Postoperative pain management of the adult patient. IARS review Course Lectures, 1996
3. Liu S, Carpenter RL, Neal JM. Epidural anesthesia and analgesia, role in postoperative outcome. Anesthesiology 1995;82:1474-1506
4. Acute Pain Management: Operative or Medical Procedures and Trauma; Agency for Health Care Policy and Research (AHCPR), 1992