April 6, 2010 ( Updated with commentary April 20, 2010 ) — For the first time in more than a decade, the American Society of Anesthesiologists Task Force on Chronic Pain Management has updated its chronic pain guidelines.

"The major change with this guideline is the fact that the guideline is developed from the perspective of interventions used to treat chronic pain," lead study author Richard Rosenquist, MD, from the University of Iowa Hospital, Iowa City, said in an interview. "Instead of looking at how to treat a given diagnosis, such as low back pain, the guideline examines the evidence to support the use of a broad range of interventions to treat chronic pain."

The objectives are to optimize pain control, enhance physical and psychological well-being, and minimize adverse outcomes.

The new guidelines appear in the April issue of Anesthesiology.

The 12-member task force consists of anesthesiologists in both private and academic practice from various parts of the United States. The group also worked with members of the American Society of Regional Anesthesia and Pain Medicine.

The new guidelines appear in the April issue of Anesthesiology.

The recommendations apply to patients with chronic noncancer, neuropathic, somatic, or visceral pain. The task force focused on interventional diagnostic procedures including diagnostic joint block, nerve block, and neuraxial opioid trials.

Focus on Interventional Diagnostic Procedures

The team agreed that findings from the patient history, physical examination, and diagnostic evaluation should be combined to provide an individualized treatment plan focused on optimizing the risk-to-benefit ratio. Treatment should progress from a lesser to greater degree of invasiveness.

"Whenever possible," the task force reports, "direct and ongoing contact should be made and maintained with the other physicians caring for the patient to ensure optimal care."

The new guidelines advocate for multimodal interventions for patients with chronic pain. The task force suggests that a long-term approach that includes periodic follow-up evaluations should be developed and implemented as part of the overall treatment strategy. In addition, when available, multidisciplinary programs may be used.

The new guidelines detail

• ablative techniques,
• acupuncture,
• blocks,
• botulinum toxin,
• electrical nerve stimulation,
• epidural steroids,
• intrathecal drug therapies,
• minimally invasive spinal procedures,
• pharmacologic management,
• physical therapy,
• psychological treatment, and
• trigger point injections.

The task force defines chronic pain as pain of any cause not directly related to neoplastic involvement associated with a medical condition or extending in duration beyond the expected temporal boundary of tissue injury and normal healing and adversely affecting the function or well-being of the individual.

Drugs for chronic pain include anticonvulsants, antidepressants, benzodiazepines, N-methyl-D-aspartate receptor antagonists, nonsteroidal anti-inflammatories, opioid therapy, skeletal muscle relaxants, and topical agents. The task force discusses each in detail and recommends strategies for monitoring and managing adverse effects and patient compliance.

Asked by Medscape Neurology to comment, Roger Chou, MD, lead author of the American Pain Society and American Academy of Pain Medicine opioids guidelines, raised concerns that the approach is so broad, covering all interventions for any type of chronic pain, that it might be difficult to apply in clinical practice.

Guidelines Too Broad?

"The guideline has to cover so many areas that it is difficult to understand the nuances of how to use the different interventions or provide detail on how to individualize their use to specific patients and situations," said Dr. Chou from the Oregon Health and Science University in Portland.

Dr. Chou also raises concerns about task force reliance on observational studies recommending interventions — even when randomized controlled trials are available that show no benefit.

"For example, the vertebroplasty recommendation," Dr. Chou said. "It is difficult to justify using observational studies to trump well-done randomized controlled trials."

He suggests the recommendations do not take into account the magnitude of clinical benefit or the presence and degree of inconsistency among studies.

"If you have well-done randomized controlled trials that come up with different results, that means you can’t even replicate results in highly controlled conditions," Dr. Chou said. "Why would we think we can reproduce the results in the far messier world of clinical practice?"

He added, "Any statistical heterogeneity is buried in the appendix tables showing the results of the meta-analyses, and there isn’t enough detail to determine whether pooling was appropriate in the first place or even which studies were pooled."

There are situations, he says, like radiofrequency ablation, where some trials found no benefit and others found some benefit. "And the overall benefit is not large even in the positive trials yet the recommendation is 'strong' to do it."

Dr. Chou said the task force's decision to survey members and consultants and include these opinions when making recommendations introduces the possibility of stakeholder bias.

Debating the Recommendations

"There is obvious financial self-interest for pain specialists to want recommendations that support use of procedures that they perform," Dr. Chou said. "It is also doubtful that many of the surveyed folks were well versed in the evidence and the issues in interpretation of the evidence. Rather, many were probably voting by their gut reaction or simply according to how they already practice. This process seems more consistent with a popularity contest than an evidence-based process," he said.

Dr. Rosenquist counters that the American Society of Anesthesiologists guideline process is extremely rigorous and incorporates a number of steps that are not used by other groups.

He acknowledges the new guidelines are generally supportive of interventional procedures and are not entirely congruent with other recent guidelines. The process varies among groups, he said, and this will have an impact on recommendations.

The task force is evaluating external response and is planning to update the guidelines again in 5 years. This latest version covers a range of advances not included in the first guidelines published in 1997. As a result, the number of pages has more than doubled in the new publication. The complete guidelines are available online.

Financial disclosures for the American Society of Anesthesiologists task force were not provided. Dr. Chou has disclosed no relevant financial relationships.

Anesthesiology. 2010;112:810-833.

Clinical Context

Clinical Implications

• Chronic pain is defined as pain of any cause not directly related to neoplastic involvement, associated with a chronic medical condition or extending in duration beyond the expected temporal boundary of tissue injury and normal healing, and adversely affecting the function or well-being of the individual.
• Chronic pain management usually includes multimodal interventions, pharmacologic management, and cognitive behavioral therapy. A long-term approach that includes periodic follow-up evaluations should be developed and implemented as part of the overall treatment strategy.

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