Email this Page to a Friend

Clinical Corner

This Editorial has been written by the specialist opinion leader, W Michael Hooten, MD
Departments of Anesthesiology, Psychiatry and Psychology, Mayo Clinic, Rochester, Minnesota and published in the latest issue of the serial publication, Drugs in Context.

For more information, you can download a free-of-charge Quick Reference Guide to the Fentanyl in Chronic Pain issue of Drugs in Context which is designed to give you an insight into the numerous key points of information and practical guidance contained in each issue, via carefully selected quotations taken directly from each part of the publication.

CSF Medical Communications publishes Drugs in Context which aims to provide clinicians around the world with a comprehensive, authoritative and independent review of all the significant data on a specific drug, placed in the context of the disease area and today's clinical practice. Each issue comprises four parts - an opening Editorial, a Disease Overview, a Drug Review and finally an Improving Practice section. Each drug is placed within the context of its indications and the clinical practice situation concerned.

Pain is a sensory and emotional experience that is common to all individuals. However, the sensory and the emotional interpretations of pain are unique experiences. This dichotomous assertion is supported by neuroscience research which shows that nociceptive pathways subserve cortical and subcortical regions responsible for modulating emotions and behaviors.1 The heterogeneity of this paradigm is further compounded by two naturalistic phenomena - acute and chronic pain.

The experience of acute pain is self-protective and vital to existence. The experience of acute pain heralds the occurrence of minor or major tissue damage, and prompts appropriate behavior to limit further injury. In the setting of trauma, the initial behavioral response - first-order behaviors - serves to remove the individual from the causative agent or event. Consequently, first-order behaviors ensure the immediate survival of the individual. If tissue injury has been sustained or is thought to have occurred, the individual will generally seek medical care. The primary function of this behavior - second-order behavior - is health restoration. First- and second-order behaviors are evident in many acute pain states. For example, first-order behaviors of an individual with abdominal pain would include searching for an environmental cause or altering eating habits. If ongoing injury or disease were suspected, second-order behaviors would prompt the individual to seek medical care or search for information about diseases associated with abdominal pain. A subsequent diagnosis of an underlying illness (e.g. cholelithiasis) would then lead to a series of second-order behaviors manifested as involvement in various medical and surgical interventions. The treatment of acute pain with opioids and various adjunctive analgesic medications falls within the clinical remit of most primary-care or general medical practices. The duration of analgesic use is time limited and, following resolution of the inciting event, the premorbid level of functioning is restored. In the treatment of acute pain, few ethical or clinical controversies exist where first- and second-order behaviors are easily identified and often facilitate a successful outcome. However, these issues become more complex in the setting of chronic pain.

The genesis of chronic pain can be traced to an acute pain episode in a limited number of circumstances where persistent symptoms are experienced and conceptualized as an extension of some inciting event. More often, however, a discrete event cannot be identified. Consequently, first-order behaviors may be less prominent in the chronic pain setting but, when present, should be interpreted carefully. This can be illustrated in the following case. A middle-aged individual seeks medical attention for a 15-20-year history of low-back pain. Further history reveals subtle changes in the patient's pain symptomatology, whereupon the diagnostic evaluation demonstrates the presence of an occult medical illness. The majority of patients with chronic pain are engaged in constructive second-order behaviors and are motivated to restore health and improve their quality of life. Conversely, maladaptive second-order behaviors manifest as, among others, recurrent requests for diagnostic testing, procedures and analgesic medications, symptom amplification and seeking multiple opinions. When maladaptive second-order behaviors are evident, important confounding variables should be sought including underlying symptoms of depression and anxiety, medication misuse and substance abuse, pain-related psychosocial dysfunction and overt secondary gain. In comparison with acute pain, the treatment of chronic pain is not time-limited and, in general, no single intervention will provide the desired therapeutic outcome. The successful management of chronic pain requires a multimodal and often a multidisciplinary approach that may involve the concurrent use of opioids and other analgesic medications, physical therapy and reconditioning, cognitive-behavioral therapy (CBT) and treatment of comorbid psychiatric illness.

Recognition and differentiation of first- and second-order behaviors can facilitate the evaluation and treatment of both acute and chronic pain. This simple construct provides the practitioner with a framework for effectively organizing and addressing the sensory and emotional aspects of pain from a clinically based behavioral perspective. In the current era, where the knowledge base of pain medicine is rapidly expanding, development of a solid clinically oriented framework is vital to the orderly integration of new evidence-based therapeutics into daily practice.

Reference
1 Rome HP, Rome JD. Limbically augmented pain syndrome (LAPS): kindling, corticolimbic sensitization, and the convergence of affective and sensory symptoms in chronic pain disorders. Pain Med 2000; 1: 7-23.