Perioperative management of acute pain in the opioid-dependent patient.

PAIN is “an unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage.” In settings where pain is poorly controlled, patients suffer needlessly and may develop untoward emotional and cognitive responses that negatively affect behavior, rehabilitation, and quality of life. Providing rapid and effective relief of pain remains a humanitarian issue, whereas allowing patients to suffer as a result of analgesic undermedication may be considered a breach of fundamental human rights. Noticeable shifts in attitude have occurred in recent years regarding the use of opioids for the treatment of benign and malignancy-related pain. Primary care physicians and pain specialists prescribe opioids to a greater number of patients and in doses appropriate to needs. A variety of opioid analgesics and delivery systems have been introduced that have increased patient satisfaction, physician acceptance, and overall use. Concomitant with improvements in pain relief and quality of life, an increasing number of patients are affected by issues related to opioid tolerance and physical dependence. There have been only a small number of published reviews that address the treatment of acute pain in patients with substance abuse disorders, and fewer have focused specifically on perioperative pain management in opioid-dependent patients. This review outlines factors responsible for opioid tolerance, physical dependence, and addiction and provides perioperative analgesic dosing guidelines for this specialized subset of patients. Many patients who present for surgery and anesthesia may be opioid dependent or at least moderately tolerant to the therapeutic effects of opioid analgesics. Causal factors underlying dependency include substance use disorder and, more commonly, legitimate use of opioid analgesics for treatment of chronic benign pain or malignancy-associated pain. Perioperative management of opioid-dependent patients poses a special challenge to primary caregivers, anesthesiologists, and pain specialists alike. This problem emanates from the often-conflicting needs to balance the rights of the patient on one hand and concerns of safety, diversion, and abuse on the other, thus raising important ethical issues. The percentage of patients to whom opioid analgesics for chronic pain are prescribed has increased dramatically in recent years. An Australian study found that in 83% of patients with chronic pain, including back pain, other forms of benign pain, and cancer pain, opioids were prescribed by the patients’ general practitioners at the time of referral to a multidisciplinary pain center. Moreover, 47% of these patients were treated with strong opioids, such as morphine, oxycodone, and methadone. In another study, long-term opioid use and dose escalation was noted in one third of patients with chronic noncancer pain. Factors responsible for the increased acceptance and prescription of opioid analgesics include physician education, concerns of analgesic undermedication and inadequate pain control, the favorable side effect profiles of newer semisynthetic and sustained-release opioids, and morbidity associated with nonsteroidal antiinflammatory drugs. Opioid-dependent patients, particularly substance abusers, may present with organ damage, infectious diseases such as human immunodeficiency virus, tuberculosis, hepatitis, associated psychological disorders, and drug-specific adaptations such as tolerance, physical dependence, and withdrawal. These variables alone or in combination may diminish opioid analgesic effectiveness in the perioperative setting. The following issues should be considered to provide a comprehensive pain management strategy: (1) key concepts and definitions including substance abuse, physical versus psychological dependence, and tolerance development; (2) clinical differentiation of opioid dependency; (3) preoperative assessment issues; and (4) postoperative management issues. * Research Associate in Anesthesiology, † Professor of Anesthesiology.