Pain assessment in chronic pancreatitis: A comparative review of methods

Interventions for Pancreatitis-New Approaches, Knowledge Gaps, and Research Opportunities: Summary of a National Institute of Diabetes and Digestive and Kidney Diseases Workshop

ABSTRACT

There exists no cure for acute, recurrent acute or chronic pancreatitis and treatments to date have been focused on managing symptoms. A recent workshop held by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) focused on interventions that might disrupt or perhaps even reverse the natural course of this heterogenous disease, aiming to identify knowledge gaps and research opportunities that might inform future funding initiatives for NIDDK. The breadth and variety of identified active or planned clinical trials traverses the spectrum of the disease and was conceptually grouped for the workshop into behavioral, nutritional, pharmacologic and biologic, and mechanical interventions. Cognitive and other behavioral therapies are proven interventions for pain and addiction, but barriers exist to their use. Whilst a disease specific instrument quantifying pain is now validated, an equivalent is lacking for nutrition - and both face challenges in ease and frequency of administration. Multiple pharmacologic agents hold promise. Ongoing development of Patient Reported Outcome (PRO) measurements can satisfy Investigative New Drug (IND) regulatory assessments. Despite multiple randomized clinical trials demonstrating benefit, great uncertainty remains regarding patient selection, timing of intervention, and type of mechanical intervention (endoscopic versus surgery). Challenges and opportunities to establish beneficial interventions for patients were identified.

Quality of Life and Pain in Patients With Chronic Pancreatitis

INTRODUCTION

The quality of life (QoL) of patients with chronic conditions is a function of factors associated with the illness, its natural course, and treatment as well as those related to the patient. Chronic pancreatitis (CP) is a critical public health problem. Chronic pancreatitis patients can experience chronic pain with different mechanisms, malabsorption, diabetes, and cachexia.

OBJECTIVE

Chronic pancreatitis (CP) is a critical public health problem. CP patients can experience chronic pain with different mechanisms, malabsorption, diabetes, and cachexia. The aim of the study was to assess the Quality of Life (QoL) of patients with CP and identify factors affecting QoL.

METHODS

104 patients diagnosed with CP from the hospital in Wrocław, Poland, were included. The study was conducted using our own questionnaire, the World Health Organization Quality of Life-BREF (WHOQOL-BREF) scale, the 36-Item Short Form Health Survey (SF-36), and the Visual Analog Scale (VAS).

RESULTS

The mean total SF-36 score was 47.7, with the highest mean rating for the physical functioning domain. The mean VAS pain score was 5.13. Pain intensity was significantly correlated with impairments in activities of daily living (P = 0.001), the need to reduce their duration (P = 0.001), and the performance of physical activity (P = 0.003). Comorbidities, education, and age have a significant relationship with only some domains of SF-36.

CONCLUSIONS

One aspect that has an impact on QoL impairment is pain which perception is governed by the same brain regions in which abnormalities result in depression and anxiety. QoL in CP patients also depends on the patient's age, comorbidities, and level of education.

Pain patterns in chronic pancreatitis and chronic primary pain

BACKGROUND

Abdominal pain is the most distressing symptom of chronic pancreatitis (CP), and current treatments show limited benefit. Pain phenotypes may be more useful than diagnostic categories when planning treatments, and the presence or absence of constant pain in CP may be a useful prognostic indicator.

AIMS

This cross-sectional study examined dimensions of pain in CP, compared pain in CP with chronic primary pain (CPP), and assessed whether constant pain in CP is associated with poorer outcomes.

METHODS

Patients with CP (N = 91) and CPP (N = 127) completed the Comprehensive Pancreatitis Assessment Tool. Differences in clinical characteristics and pain dimensions were assessed between a) CP and CPP and b) CP patients with constant versus intermittent pain. Latent class regression analysis was performed (N = 192) to group participants based on pain dimensions and clinical characteristics.

RESULTS

Compared to CPP, CP patients had higher quality of life (p < 0.001), lower pain severity (p < 0.001), and were more likely to use strong opioids (p < 0.001). Within CP, constant pain was associated with a stronger response to pain triggers (p < 0.05), greater pain spread (p < 0.01), greater pain severity, more features of central sensitization, greater pain catastrophising, and lower quality of life compared to intermittent pain (all p values ≤ 0.001). Latent class regression analysis identified three groups, that mapped onto the following patient groups 1) combined CPP and CP-constant, 2) majority CPP, and 3) majority CP-intermittent.

CONCLUSIONS

Within CP, constant pain may represent a pain phenotype that corresponds with poorer outcomes. CP patients with constant pain show similarities to some patients with CPP, potentially indicating shared mechanisms.

Development of the Comprehensive Pain Assessment Tool Short Form for Chronic Pancreatitis: Validity and Reliability Testing

BACKGROUND & AIMS

Pain is the foremost complication to chronic pancreatitis (CP), but no validated questionnaires for assessment exist. The COMPAT questionnaire includes all relevant pain dimensions in CP, but a short form is needed to make it usable in clinical practice.

METHODS

The full COMPAT questionnaire was completed by 91 patients and systematically reduced to 6 questions. Pain severity and analgesic use were merged, leaving 5 pain dimensions. The pain dimension ratings were normalized to a 0-100 scale, and the weighted total score was calculated, where 3 dimensions were weighted double. Reliability of the short form was tested in a test-retest study in 76 patients, and concurrent validity tested against the Brief Pain Inventory and Izbicki pain questionnaire. Convergent validity was verified using confirmatory factor analysis, and criterion validity tested against quality-of-life and hospitalization rates.

RESULTS

The COMPAT-SF questionnaire consisted of the following pain dimensions: a) pain severity, b) pain pattern, c) factors provoking pain, d) widespread pain, and e) a qualitative pain-describing dimension. Quality of life correlated with the total score and all pain dimensions (P <.05). The total score, pain severity, pain pattern, and factors provoking pain were correlated with hospitalization rates (P <.05). The total score correlated with the Izbicki and Brief Pain Inventory scores (P <.0001). The reliability of the questionnaire in patients in a stable phase was good with an interclass correlation coefficient of 0.89.

CONCLUSION

The COMPAT-SF questionnaire includes the most relevant aspects of pain in CP and is a feasible, reliable, and valid pain assessment instrument recommended to be used in future trials.

Assessment of pain associated with chronic pancreatitis: An international consensus guideline

Pain is the most common symptom in chronic pancreatitis (CP) with a major impact on quality of life. Few validated questionnaires to assess pain in CP exist, and the lack of consensus negatively impacts clinical management, research and meta-analysis. This guideline aims to review generic pain questionnaires for their usability in CP, to outline how pain assessment can be modified by confounding factors and pain types, to assess the value of additional measures such as quality of life, mental health and quantitative sensory testing, and finally to review pain assessment questionnaires used specifically in CP. A systematic review was done to answer 27 questions that followed the PICO (Population; Intervention; Comparator; Outcome) template. Quality of evidence of the statements was judged by Grades of Recommendation, Assessment, Development and Evaluation (GRADE) criteria. The manuscript was sent for review to 36 experts from various disciplines and continents in a multi-stage Delphi process, and finally reviewed by patient representatives. Main findings were that generic pain instruments are valid in most settings, but aspects of pain are specific for CP (including in children), and instruments have to account for the wide phenotypic variability and development of sensitization of the central nervous system. Side effects to treatment and placebo effects shall also be considered. Some multidimensional questionnaires are validated for CP and are recommended together with assessment of quality of life and psychiatric co-morbidities. This guideline will result in more homogeneous and comprehensive pain assessment to potentially improve management of painful CP.

Pancreatic Pain-Knowledge Gaps and Research Opportunities in Children and Adults: Summary of a National Institute of Diabetes and Digestive and Kidney Diseases Workshop

ABSTRACT

A workshop was sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases to focus on research gaps and opportunities in pancreatic pain. The event was held on July 21, 2021, and structured into 4 sessions: (1) pathophysiology; (2) biomarkers, mediators, and pharmacology of pain; (3) pain assessment; and (4) pain treatment challenges and opportunities. The current state of knowledge was reviewed; many knowledge gaps and research needs were identified that require further investigation. Common themes included the need to better understand the underlying mechanisms of pain in pancreatic diseases, the relationship of visceral neural pathways and central pain centers, the role of behavioral factors and disorders on the perception of pain, and differences in pain perception and processes in children when compared with adults. In addition, the role of genetic risk factors for pain and the mechanisms and role of placebos in pain treatment were discussed. Methods of pain assessment including quantitative sensory testing were examined, as well as the process of central sensitization of pain. Finally, newer approaches to pain management including cognitive behavioral therapy, nerve stimulation, experimental (nonopioid) drugs, and cannabinoid compounds were covered.

Severe Pain in Chronic Pancreatitis Patients: Considering Mental Health and Associated Genetic Factors

Pain is the most distressing and disruptive feature of recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP) resulting in low quality of life (QOL) and disabilities. There is no single, characteristic pain pattern in patients with RAP and CP. Abdominal imaging features of CP accurately reflect morphologic features but they do not correlate with pain. Pain is the major driver of poor quality of life (QOL) and it is the constant pain, rather than intermittent pain that drives poor QOL. Furthermore, the most severe constant pain experience in CP is also a complex condition. The ability to target the etiopathogenesis of severe pain requires new methods to detect the exact pain mechanisms in an individual at cellular, tissue, system and psychiatric levels. In patients with complex and severe disease, it is likely that multiple overlapping mechanisms are simultaneously driving pain, anxiety and depression. Quantitative sensory testing (QST) shows promise in detecting alterations in central processing of pain signals and to classify patients for mechanistic and therapeutic studies. New genetic research suggests that genetic loci for severe pain in CP overlap with genetic loci for depression and other psychiatric disorders, providing additional insights and therapeutic targets for individual patients with severe CP pain. Well-designed clinical trials that integrate clinical features, QST, genetics and psychological assessments with targeted treatment and assessment of responses are required for a quantum leap forward. A better understanding of the context and mechanisms contributing to severe pain experiences in individual patients is predicted to lead to better therapies and quality of life.

Pain Management in Chronic Pancreatitis: Summary of Clinical Practice, Current Challenges and Potential Contribution of the M-ANNHEIM Classification

Abdominal pain, diarrhea with weight loss, and endocrine insufficiency represent the dominant symptoms of chronic pancreatitis (CP). High intensity of pain and constant pain have been shown to reduce quality of life in CP and may result in disability and increased health resource utilization. Various basic challenges and unanswered questions still exist regarding the treatment of pain in CP. Recently, limited evidence has been gained that early surgery for painful disease might be associated with better treatment results. Thus, timing of pancreatic surgery in painful disease represents a major issue that needs to be clarified in future studies. In this context, surveillance of patients is necessary in clinical practice. It appears that a generally accepted classification of the disease represents a major requirement for inter-institutional comparison of data with future progress in clinical research. Among recently proposed classification systems, the M-ANNHEIM classification system of CP with its recently presented M-ANNHEIM Surgery Score might be a useful tool to picture the course of the disease and to monitor treatment results. Future research is required to clarify the possible role of this system in the management of pain in CP. In the present article, we provide an overview of current status, challenges, and unanswered questions in the treatment of pain in CP, and we demonstrate the potential benefits of the M-ANNHEIM classification system in the management of painful CP.

A Network Meta-analysis of Surgery for Chronic Pancreatitis: Impact on Pain and Quality of Life

BACKGROUND

The surgical operation associated with improved pain and quality of life (QoL) in patients with chronic pancreatitis (CP) is unknown.

METHOD

The Scopus, EMBASE, Medline and Cochrane databases were systematically searched until May 2019, and all randomised trials (RCTs) comparing surgical operations for CP pain were included in a network meta-analysis (NMA).

RESULTS

Four surgical operations for treating CP were directly compared in eight RCTs including 597 patients. Patients were mainly male (79%, 474/597) with alcoholic CP (85%, 382/452). Surgical operations included were pancreatoduodenectomy (224, 38%), Berne procedure (168, 28%), Beger procedure (133, 22%) and Frey procedure (72, 12%). The NMA revealed that the Beger procedure ranked best for pain relief, whilst the Frey procedure ranked best for postoperative QoL, postoperative pancreatic fistula rate and postoperative exocrine insufficiency rate during a median follow-up of 26 months (reported range 6-58 months). Overall the Frey procedure ranked best for the combination of primary outcome measures based on surface under cumulative ranking curve scores.

CONCLUSIONS

Overall the Frey procedure may perform the best for both pain relief and postoperative QoL in patients with CP. Further trials are warranted in defining the role of surgery in relation to endotherapy.

International consensus guidelines on interventional endoscopy in chronic pancreatitis. Recommendations from the working group for the international consensus guidelines for chronic pancreatitis in collaboration with the International Association of Pancreatology, the American Pancreatic Association, the Japan Pancreas Society, and European Pancreatic Club

BACKGROUND/OBJECTIVES

This paper is part of the international consensus guidelines on chronic pancreatitis, presenting for interventional endoscopy.

METHODS

An international working group with experts on interventional endoscopy evaluated 26 statements generated from evidence on 9 clinically relevant questions. The Grading of Recommendations Assessment, Development, and Evaluation approach was used to evaluate the level of evidence. To determine the level of agreement, a nine-point Likert scale was used for voting on the statements.

RESULTS

Strong consensus was obtained for 15 statements relating to nine questions including the recommendation that endoscopic intervention should be offered to patients with persistent severe pain but not to those without pain. Endoscopic decompression of the pancreatic duct could be used for immediate pain relief, and then offered surgery if this fails or needs repeated endoscopy. Endoscopic drainage is preferred for portal-splenic vein thrombosis and pancreatic fistula. A plastic stent should be placed and replaced 2-3 months later after insertion. Endoscopic extraction is indicated for stone fragments remaining after ESWL. Interventional treatment should be performed for symptomatic/complicated pancreatic pseudocysts. Endoscopic treatment is recommended for bile duct obstruction and afterwards surgery if this fails or needs repeated endoscopy. Surgery may be offered if there is significant calcification and/or mass of the pancreatic head. Percutaneous endovascular treatment is preferred for hemosuccus pancreaticus. Surgical treatment is recommended for duodenal stenosis due to chronic pancreatitis.

CONCLUSIONS

This international expert consensus guideline provides evidenced-based statements concerning indications and key aspects for interventional endoscopy in the management of patients with chronic pancreatitis.

Earlier surgery improves outcomes from painful chronic pancreatitis

The timing of surgery for painful chronic pancreatitis (CP) may affect outcomes.Clinical course, Izbicki pain scores, and pancreatic function were retrospectively compared and analyzed between patients undergoing either early or late surgery (< 3 or ≥ 3 years from diagnosis) for painful CP in a single center from 2007 to 2012.The early surgery group (n = 98) more frequently than the late group (n = 199) had abdominal pain with jaundice (22.4% vs 9.5%, P = .002) and pancreatic mass +/- ductal dilatation (47% vs 27%, P < .001), but less frequently abdominal pain alone (73.5% vs 85.9%, P = .009), ductal dilatation alone (31% vs 71%, P < .001), parenchymal calcification (91.8% vs 100%, P < .001) or exocrine insufficiency (60% vs 72%, P = .034); there were no other significant differences. The early group had longer hospital stay (14.4 vs 12.2 days, P = .009), but no difference in complications. Significantly greater pain relief followed early surgery (complete 69% vs 47%, partial 22% vs 37%, none 8% vs 16%, P = .01) with lower rates of exocrine (60% vs 80%, P = .005) and endocrine insufficiency (36% vs 53%, P = .033).Our data indicate that early surgery results in higher rates of pain relief and pancreatic sufficiency than late surgery for chronic pancreatitis patients. Frey and Berne procedures showed better results than other surgical procedures.

Accelerating the Drug Delivery Pipeline for Acute and Chronic Pancreatitis: Summary of the Working Group on Drug Development and Trials in Chronic Pancreatitis at the National Institute of Diabetes and Digestive and Kidney Diseases Workshop

The lack of effective therapeutic agents specifically tailored for chronic pancreatitis (CP) has hampered clinical care and negatively impacted patients' lives. New mechanistic insights now point to novel therapies, which involve both recently developed and/or repurposed agents. This working group focused on 2 main outcomes for CP: pain and progression of disease. The goal is to frame the essential aspects of trial design including patient-centered outcomes, proposed methods to measure the outcomes of pain and progression, and study design considerations for future trials to facilitate rapid drug development for patients with CP.

A comprehensive pain assessment tool (COMPAT) for chronic pancreatitis: Development, face validation and pilot evaluation

BACKGROUND/OBJECTIVES

Chronic pancreatitis (CP) pain is challenging to treat. Treatment selection is hampered by there being no validated pain assessment tool that accounts for the complexity of CP pain and its underlying mechanisms. This study aims to develop a comprehensive pain assessment tool (COMPAT) specific for CP, evaluate its face validity with experts and patients and test it with a pilot cohort of patients.

METHODS

COMPAT was developed from existing pain assessment tools and a literature review. Face validity was conducted by pancreatologists and CP patients using an item-content validity index for importance, relevance and clarity. Subsequent revisions were made to COMPAT. A pilot cohort of CP patients tested COMPAT.

RESULTS

COMPAT was developed and covered all important aspects of CP pain. Experts and CP patients reported that 70% of questions were important and relevant to CP pain. Most experts were willing to use COMPAT in clinic, ward/hospital and research settings. The most common location of pain was the epigastrium and food was the most important trigger. Pain Pattern C (constant background pain with pain attacks), had significantly higher frequency of pain attacks, higher opioid use, and affective descriptors of pain than Pattern A (pain attacks with no background pain).

CONCLUSIONS

COMPAT has high face validity and met with high acceptance. CP patients successfully self-reported their pain with COMPAT. The results reveal many differences in the CP pain within the pilot cohort, which may reflect different mechanisms of pain. A larger prospective cohort study is planned to further validate COMPAT.

Medical Management of Pain in Chronic Pancreatitis

The medical management of pain in chronic pancreatitis continues to pose significant challenges for clinicians caring for these patients. There are increasing data, suggesting that pain in chronic pancreatitis is largely due to peripheral and central sensitization that evolves, over time, as a result of nociceptive afferent associated with chronic inflammation and fibrosis of the pancreas. In many instances, patients rapidly progress to requiring opioid analgesics for the adequate treatment of pain despite the unequivocal risks associated with the long-term use of these drugs. Centrally acting drugs, such as gabapentinoids, appear to be effective means of treating pain due to their inhibition of neurotransmitters involved in central sensitization, but side effects limit their use. The present review explores the evidence for various non-pharmacologic and pharmacologic treatments for pain in chronic pancreatitis.

Endoscopic vs. Surgical Interventions for Painful Chronic Pancreatitis: What is Needed for Future Clinical Trials

The treatment of painful chronic pancreatitis remains controversial. The available evidence from two randomized controlled trials favor surgical intervention, whereas an endotherapy-first approach is widely practiced. Chronic pancreatitis is complex disease with different genetic and environmental factors, different pain mechanisms and different treatment modalities including medical, endoscopic, and surgical. The widely practiced step-up approach remains unproven. In designing future clinical trials there are some important pre-requisites including a more comprehensive pain assessment tool, the optimization of conservative medical treatment and interventional techniques. Consideration should be given to the need of a control arm and the optimal timing of intervention. Pending better designed studies, the practical way forward is to identify subgroups of patients who clearly warrant endotherapy or surgery first, and to design the future clinical trials for the remainder.