The American Pain Society, for the first time, has released a clinical practice guideline on managing postoperative pain.
The guideline was created with input from the American Society of Anesthesiologists (ASA) and was subsequently approved by the American Society for Regional Anesthesia and Pain Medicine (ASRA), and was based on the 23-member panel’s review of 6,500 scientific abstracts and primary studies.
“The intent of the guideline is to provide evidence-based recommendations for better management of postoperative pain,” said Roger Chou, MD, lead author of the guideline and head of the Pacific Northwest Evidence-based Practice Center, located at Oregon Health & Science University, in Portland. Numerous studies have suggested that the majority of surgical patients receive inadequate pain relief, Dr. Chou said. Roughly 80% of surgical patients report pain after surgery, with three-fourths classifying their pain as moderately or very severe, and more than half say their pain management is not adequate. Such levels of pain, Dr. Chou said, can raise the risk for prolonged postsurgical pain, mood disorders and physical impairment.
“The target audience is all physicians who manage pain resulting from surgery,” said Dr. Chou.
The guideline is divided into 32 specific recommendations. The authors rate each according to the strength of the recommendation and the quality of evidence. Strength of recommendations does not necessarily correspond to strength of evidence. For example, in the first recommendation, which Dr. Chou noted is among the most important, the panel “strongly” recommends “patient and family-centered, individually tailored education” for postoperative pain management, despite low-quality evidence. The benefits very likely outweigh any harms, Dr. Chou explained.
A foundational recommendation promotes concurrent use of multiple therapies, Dr. Chou said. These can be different types of medications and/or different methods of administration. They can also include nonmedical techniques, such as cognitive-behavioral therapy, patient and caregiver education, and/or methods such as transcutaneous electrical nerve stimulation as adjuncts to pharmacologic therapy. “Nonpharmacological therapies tend to be underused in many centers,” Dr. Chou said. “We want clinicians to be aware of them, and to think about whether they can be part of the regimens.”
The rationale is that pain can involve multiple mechanisms. “Medication[s] and techniques that target different mechanisms of action in the peripheral and/or central nervous system … might have additive or synergistic effects and more effective pain relief compared with single-modality interventions,” according to the guideline. Moreover, randomized controlled trials have demonstrated superior pain relief and reduced opiate consumption compared with administration of a single medication via a single technique, Dr. Chou said.
“The main benefit of lower opioid doses is reduced side effects, including GI [symptoms], nausea, etc., which can be quite severe,” Dr. Chou said. “There is some risk of accidental overdose with high doses as well. There is no evidence that I am aware of showing an association between the doses used for management of postoperative pain and risk of addiction.”
However, reducing use of opioids in low-risk procedures for which they are not needed may decrease long-term use and associated abuse or addiction, Dr. Chou pointed out. “People who receive opioids for low-risk procedures, like cataract surgery, are much more likely to be using opioids a year later than people who didn’t get them,” he said. “We are learning that how we use opioids for acute pain may have long-term impacts.”
Other critical recommendations include “preoperative evaluation including assessment of medical and psychiatric comorbidities, concomitant medications, history of chronic pain, substance abuse …” and use of “a validated pain assessment tool to track responses to postoperative pain treatments and adjust treatment plans accordingly,” the guideline states (both recommendations are strong, with low-quality evidence).
Still other recommendations advocate specific methods of drug administration—for example, oral over IV opioids—and avoidance of intramuscular injection for administration of analgesics to manage postoperative pain (strong recommendation, moderate-quality evidence for both).
Part of the rationale for use of psychological techniques is that expectations can powerfully influence perceived pain, Dr. Chou said. These techniques include guided imagery using positive images, which the patient can learn to associate with the surgery, which “seems to have some effectiveness in at least some studies,” Dr. Chou said.
Relaxation techniques and music are other modalities that can reduce pain, Dr. Chou said. None of these, he noted, are meant to replace the mainstay of therapy, which for most patients is systemic opioids. But they can both improve the effectiveness of pain mitigation and reduce the use of opioids.
According to Daniel Warren, MD, the best thing about the guideline, which was published in The Journal of Pain (2016;17:131-157), is that thoughtful, engaged practitioners at institutions with new or growing surgery services can use it as leverage with administrations to ensure adequate resources for postoperative pain care. Dr. Warren is deputy chief of the Department of Anesthesia and medical director for Clinic Services at Virginia Mason Medical Center, in Seattle.
“The most important take-away for all involved is that a systems-based approach is needed for the best outcomes, and that postoperative pain care begins before surgery, with expectation-setting and appropriate patient evaluation, patient education and creation of an appropriate care plan,” Dr. Warren said.
Dr. Warren emphasized the importance of a holistic approach to treatment. By itself, “technical competence is not sufficient for a successful postoperative pain management pathway,” he said. “You have to have multidisciplinary involvement and shared goals within the institution, and a basis of agreement for how patients will be cared for throughout the whole pathway, f rom the time the decision is made for surgery to the transition from outpatient care to the home.”