Summaries

The Journal of Pain

Highlights from The Journal of Pain (Volume 17, No. 2, February 2016 Issue)

American Pain Society Publishes Clinical Practice Guideline for Postsurgical Pain Management

Evidence-based recommendations support using a variety of analgesic medications and techniques as well as nonpharmacological interventions.

The American Pain Society has released a new evidence-based clinical practice guideline, appearing in The Journal of Pain, with 32 recommendations to help clinicians achieve optimal pain management following surgery. According to numerous studies, the majority of surgical patients receive inadequate pain relief, which can heighten the risk for prolonged postsurgical pain, mood disorders, and physical impairment.

“The intent of the guideline is to provide evidence-based recommendations for better management of postoperative pain, and the target audience is all clinicians who manage pain resulting from surgery,” said Roger Chou, MD, lead author and head of the Oregon Evidence-Based Practice Center.

Chou said the key recommendation in the guideline, based on high-quality evidence, is wider use of a variety of analgesic medications and techniques.

“The guideline strongly advises use of multimodal anesthesia that target different mechanisms of actions in the peripheral and central nervous systems,” he said. “Randomized trials have shown that multimodal anesthesia involving simultaneous use of combinations of several medications—acting on different pain receptors or administered through different techniques—are associated with superior pain relief and decreased opioid consumption compared with use of a single medication administered by one technique.”

Chou added that evidence also indicates that nonpharmacological therapies, such as cognitive behavioral therapies and transcutaneous elective nerve stimulation, can be effective adjuncts to pharmacological therapies.

Written by a 23-member expert panel representing anesthesia, pain management, surgery, nursing, and other medical specialties, the APS guideline is based on the panel’s review of more than 6,500 scientific abstracts and primary studies.

The guideline’s 32 recommendations are rated as strong, moderate, or weak based on scientific evidence cited as high, moderate, or low quality. The recommendations are based on the premise that optimal pain management begins in the preoperative period and should be based on assessment of the patient and development of individual care plans for the surgical procedure involved.

Three other recommendations in the APS guideline are graded strong with high-quality evidence:

• Adults and children can be given acetaminophen or nonsteroidal anti-inflammatory drugs as part of multimodal analgesia for management of postoperative pain.
• Clinicians should consider surgical, site-specific, peripheral, and regional anesthetic techniques with proven efficacy in adults and children for certain procedures.
• Spinal analgesia is appropriate for major thoracic and abdominal procedures, particularly in patients at risk for cardiac and pulmonary complications or prolonged intestinal distress.

The APS guideline offers 11 other strong recommendations, based on moderate or weak evidence. The following are a few of those recommendations:

• Clinicians should provide patient- and family-centered, individually tailored education to patients and caregivers about treatment options for postoperative pain.
• Oral administration of opioids is preferred to intravenous administration for postoperative analgesia.
• Intravenous patient-controlled analgesia can be used when parenteral administration of analgesics is required.
• Clinicians should consider giving preoperative doses of celecoxib (Celebrex) in appropriate adult patients.
• Gabapentin (Neurotin, Gralise, Horizant) and pregabalin (Lyrica) can be considered for multimodal postoperative analgesia. The medications are associated with lower opioid requirements after surgery.
• Surgical facilities should provide clinicians with access to a pain specialist for patients with inadequately controlled postoperative pain.

The APS postoperative pain management guideline was endorsed by the American Society for Regional Anesthesia.

About the American Pain Society

Based in Chicago, the American Pain Society (APS) is a multidisciplinary community that brings together a diverse group of scientists, clinicians, and other professionals to increase the knowledge of pain and transform public policy and clinical practice to reduce pain-related suffering. APS is the professional home for investigators involved in all aspects of pain research including basic, translational, clinical, and health services research to obtain the support and inspiration they need to flourish professionally. APS strongly advocates expansion of high quality pain research to help advance science to achieve effective and responsible pain relief. For more information on APS, visit www.americanpainsociety.org.

The Journal of Pain is the peer-reviewed publication of the American Pain Society. To receive a PDF file of the APS Postoperative Pain Management Clinical Practice Guideline, e-mail Chuck Weber.

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PAIN

Highlights from PAIN (Volume 157, No. 2, February 2016 Issue)

Effect of Endocannabinoid Degradation on Pain: Role of FAAH Polymorphisms in Experimental and Postoperative Pain in Women Treated for Breast Cancer

Kristiina Cajanus, Emil J. Holmström, Maija Wessman, Verneri Anttila, Mari A. Kaunisto, Eija Kalso; Departments of Anaesthesiology, Intensive Care, and Pain Medicine, University of Helsinki and Helsinki University Hospital, Helsinki, Finland; Department of Molecular Genetics, Folkhälsan Institute of Genetics, Folkhälsan Research Center, Helsinki; Institute for Molecular Medicine Finland (FIMM), University of Helsinki, Finland; Analytic and Translational Genetics Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge

Endogenous analgesia is an important physiological response to stress and injury, and it has a significant role in acute and chronic pain. Both the endogenous opioid system and, particularly, the endocannabinoid system are actively investigated as potential targets for safer and more efficacious analgesics. The aim of this study was to examine this association in a subanalysis of an unpublished genome-wide association study. The study cohort consisted of 1,000 Finnish women surgically treated for breast cancer. To provide a mechanistic link, investigators also studied the association of fatty acid amide hydrolase (FAAH) polymorphisms with experimentally induced cold and heat pain. The study cohort was collected at the Breast Surgery Unit, Helsinki University Central Hospital, between August 2006 and December 2010.

Researchers found that carrying two copies of a missense variant converting proline at position 129 to threonine (rs324420) resulted in significantly lower cold pain sensitivity and less need for analgesia after surgery. A statistically significant association was found between a functional FAAH single-nucleotide polymorphism (SNP), rs324420/P129T, and cold pain sensitivity. The effect was strongest when individuals homozygous for the minor allele were compared with the other groups. For examination of cold pain sensitivity, homozygous individuals reported a numerical rating scale score 1.4 points (scale 0-10) fewer than the mean score of the other genotype groups.

Variation within the FAAH gene encoding an FAAH enzyme was shown to associate with cold pain sensitivity. Although several SNPs within the gene area studied showed evidence of association, the most likely potential causal variant is the SNP rs324420, coding for a P129T mutation in FAAH. It was significantly or nominally associated with both experimentally induced pain and postoperative oxycodone consumption. A replication study is needed to confirm these results.

Longitudinal Evaluation of Patient-Reported Outcomes Measurement Information Systems Measures in Pediatric Chronic Pain

Susmita Kashikar-Zuck, Adam Carle, Kimberly Barnett, Kenneth R. Goldschneider, David D. Sherry, Constance A. Mara, Natoshia Cunningham, Jennifer Farrell, Jenna Tress, Esi Morgan DeWitt; Division of Behavioral Medicine and Clinical Psychology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH; Department of Pediatrics, College of Medicine, University of Cincinnati, Cincinnati; James M. Anderson Center for Health Systems Excellence, Cincinnati Children’s Hospital Medical Center, Cincinnati; Pain Management Center, Cincinnati Children’s Hospital Medical Center, Cincinnati; Division of Rheumatology, Children’s Hospital Of Philadelphia, Philadelphia, PA; Department of Psychology, University of North Texas, Denton, TX; Division of Rheumatology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH

The Patient-Reported Outcomes Measurement Information System (PROMIS) was initiated by the National Institutes of Health to develop and validate patient-reported outcomes for use in clinical research and patient care. However, PROMIS measures have not been validated, nor has their sensitivity to change been evaluated in pediatric chronic pain.

Chronic pain in children is often associated with pain-related disability and reduced quality of life. The primary aim of this study was to evaluate the construct validity of PROMIS pediatric measures in children presenting for outpatient treatment of chronic pain by examining the congruence between PROMIS measures and corresponding legacy scales (i.e., validated measures currently administered in the clinic) over the course of outpatient treatment. It was hypothesized that there would be congruence between the longitudinal trajectories of PROMIS measures and corresponding legacy scales measured at baseline and two follow-up assessments. The second aim of this study was to examine the responsiveness to change of pediatric PROMIS measures in patients seen at two different chronic pain treatment settings. Differential rates of change in PROMIS scores were anticipated, with the more intensive day-treatment program yielding faster improvement.

Results provide preliminary support for the validity and responsiveness of PROMIS measures in a clinical pediatric pain population. Participants in this study were primarily school-age children with chronic musculoskeletal pain undergoing multidisciplinary treatment in one of two tertiary care pediatric settings (outpatient chronic pain clinic [CPC] and intensive amplified musculoskeletal pain program [AMP]). The construct validity of six PROMIS pediatric short-form scales (pain interference, mobility, upper extremity function, anxiety, depressive symptoms, and peer relationships) was examined in the CPC sample by comparing them with legacy instruments routinely administered in the clinic. Evidence of convergent validity was found for five of the six PROMIS scales, which corresponded well with legacy measures in all analyses performed. For each of these scales, patients’ scores on legacy measures were strongly correlated with PROMIS measures, consistency in rank order was seen, and PROMIS and legacy measures performed similarly over the course of outpatient treatment.

Significant reductions in PROMIS pain interference, fatigue, anxiety, and depressive symptom scores were found over the course of time, along with significant increases in mobility, upper extremity function, and peer relationship scores. Furthermore, as expected, the rate of change as demonstrated by the trajectories of change in PROMIS measures showed differential rates, with faster improvement in the intensive AMP program. Although the PROMIS measures of pain interference, mobility, anxiety, depressive symptoms, and peer relationships performed similarly to legacy measures administered in the CPC clinic, they did not show as steep a change in improvement trajectories over time as their corresponding legacy measures. Close examination and comparison of individual items comprising the measures reveals that this most likely relates to the unidimensionality and precision of the PROMIS measures with respect to a particular construct, whereas the legacy scales tend to be more multidimensional and capture various aspects of a construct. Although this study provides good support for the use of PROMIS measures in chronic musculoskeletal pain, results may not be generalizable for other common pediatric recurrent pain conditions or disease-related pain.