Role of differential neuroaxial blockade in the evaluation and management of pain in chronic pancreatitis

Interventional Pain Management Approaches for Control of Chronic Pancreatic Pain

OPINION STATEMENT

Treatment of persistent pain from chronic pancreatitis historically was difficult to treat. For years, focus was on opioid and other analgesics and psychological treatments. Recent studies provided evidence for decrease in analgesic intake and pain scores after properly conducted sympathetic blocks (celiac, splanchnic nerve blocks). These therapies should be considered as parts of a multimodal analgesic strategy. Animal studies suggest that spinal cord stimulation suppresses visceral hyperalgesia. Large case series of spinal cord stimulation demonstrated a significant pain relief in patients with chronic pancreatitis. Given the limitations of conservative and surgical treatments for chronic visceral pain, spinal cord stimulation may be a very useful therapeutic option.

Disease progression of acute pancreatitis in pediatric patients

BACKGROUND

Approximately 10% of patients with acute pancreatitis (AP) progress to chronic pancreatitis. Little is known about the factors that affect recurrence of pancreatitis after an initial episode. We retrospectively investigated patients with AP, focusing on their outcomes and the predictors for disease progression.

METHODS

Between July 2003 and June 2015, we retrospectively enrolled first-time AP patients with medical records on disease etiology, severity (according to the Atlanta classifications), and recurrence of AP. Independent predictors of recurrent AP (RAP) and chronic pancreatitis were identified using the logistic regression model.

RESULTS

Of the total 159 patients, 45 (28.3%) developed RAP, including two episodes of RAP in 19 patients, and 9 (5.7%) developed chronic pancreatitis. The median duration from the time of AP to the onset of RAP was 5.6 ± 2.3 months. RAP patients were identified as more common among patients with idiopathic first-time AP. The presence of severe ascites, pancreatic necrosis, and systemic complications was independent predictors of RAP in pediatric patients. Experiencing over two RAP episodes was the predictor for developing chronic pancreatitis. No influence of age or number of AP episodes was found on the occurrence of abdominal pain, pain severity, and the prevalence of any pain.

CONCLUSIONS

Severity of first-time AP and idiopathic first-time AP are related to RAP. Recurrence increases risk for progression to chronic pancreatitis. The risk of recurrence increased with increasing numbers of AP episodes.

Differential epidural block predicts the success of visceral block in patients with chronic visceral abdominal pain

BACKGROUND AND AIMS

Differential thoracic epidural regional block, also known as a differential neural block (DNB), involves the placement of an epidural catheter placed in the thoracic epidural space to achieve appropriate anesthesia in a dermatomal distribution. This is a retrospective case series evaluating how well a DNB may predict success of subsequent visceral blockade in patients with chronic abdominal pain of visceral origin.

METHODS

Of 402 patients who had a DNB performed for unexplained abdominal pain from January 2000 to January 2009, 81 patients were found to have results consistent with visceral pain and thus underwent subsequent visceral blockade. Basic demographic data, years of chronic pain, history of psychosocial issues, initial visual analog scale (VAS) pain score, pain location, and medication usage were documented in our electronic medical record database. Parameters regarding DNB and visceral blocks also were documented. Descriptive statistics were computed for all variables. The positive predictive value (PPV) for DNB for whom visceral block was successful (at least a 50% reduction in VAS) was calculated. Additionally, subjects with successful visceral blocks were compared to those with unsuccessful visceral blocks.

PARTICIPANTS

All patients with chronic abdominal pain with normal gastrointestinal studies who underwent DNB.

SETTING

Tertiary Outpatient Pain Management Clinic.

DESIGN

  Retrospective Cohort Study.

RESULTS

Mean age of patients was 46 (± 15) years, 73% were female, and median duration of pain was 5 years. 67% of subjects were taking opioid analgesics. PPV of DNB was 70.4%. Only factor found to be statistically significant with visceral block success was baseline VAS with higher scores associated with DNB predictive success (6.8 ± 1.7 vs. 5.5, 1.8; P = 0.004). Use of membrane stabilizing medications was significantly more common in subjects for whom visceral block was not successful (46% vs. 25%; P = 0.058). Area underneath curve (AUC) for VAS was found to be 0.70 (95% CI: 0.57, 0.82), which signifies fair discrimination.

CONCLUSION

Differential neural block is fairly predictive of subsequent visceral block success in patients with chronic abdominal pain of visceral origin. An initial VAS ≥ 5 provides a sensitivity of 93%, which implies that VAS < 5 may predict unsuccessful visceral block. Contrarily, a value of ≥ 8 would provide a specificity of 92% and may be used to predict success of subsequent visceral block.

Pain and opioid use in chronic pancreatitis

OBJECTIVE

Opioid therapy for pain in chronic pancreatitis (CP) is associated with tolerance and possibly opioid-induced hyperalgesia. We thus examined opioid use and pain rating in CP patients.

METHODS

Medical records of patients with established CP treated at the University of Pittsburgh Medical Center's Digestive Disorders Center between April 2008 and December 2009 were retrospectively reviewed.

RESULTS

Two hundred nineteen unique patients (53% men; age, 50 ± 1 years) were identified. At least moderate pain was initially present in 37% of the patients. Half (51%) of the patients received opioids (average morphine equivalent, 78.1 ± 12.4 mg/d). Pain severity correlated with age (r = -0.22), history of alcohol abuse (r = 0.14), affective spectrum disorders (r = 0.14), presence of coexisting pain syndromes (r = 0.24), opioid use (r = 0.49), and days with concerns about physical (r = 0.55) or mental problems (r = 0.35). In contrast, computed tomography-defined pancreatic abnormalities (calcification, pseudocysts, ductal stones, or dilation) did not correlate with pain rating. Regression analysis identified age, days with physical problems, and a coexisting chronic pain syndrome as best independent predictors of pain.

CONCLUSIONS

Chronic pancreatitis etiology, especially alcohol use, and psychosocial factors are important determinants of pain severity in CP. Successful management thus needs to go beyond treatment of changes in pancreatic morphology to effectively improve quality of life and utilization of medical resources.

Adding triamcinolone to endoscopic ultrasound-guided celiac plexus blockade does not reduce pain in patients with chronic pancreatitis

BACKGROUND & AIMS

The efficacy of endoscopic ultrasound-guided celiac plexus blockade (EUS-CPB) for painful chronic pancreatitis (CP) is uncertain. Triamcinolone is often mixed with bupivacaine to lengthen the analgesic effect. We investigated whether addition of triamcinolone increases and lengthens pain relief compared with EUS-CPB with only bupivacaine.

METHODS

We performed a single-center, blinded, randomized, controlled trial of 40 adult patients referred for EUS-CPB for treatment of painful CP. Patients were assigned randomly to groups that received EUS-CPB with triamcinolone and bupivacaine or EUS-CPB with only bupivacaine (control). Questionnaires were collected when the study began (baseline) and 1 month later. The primary end point was a decrease in the pain disability index of 10 or more points at 1 month after the procedure. Secondary end points included change in visual analogue scale, narcotic requirements, and quality of life at 1 month.

RESULTS

There were no significant differences in primary outcomes between groups (14.3% for patients who received triamcinolone vs 15.8% for controls; P = .64). The trial was stopped for futility. There was no significant difference between groups in immediate response rates (85.7% for patients who received triamcinolone vs 68.4% for control; P = .10), or other secondary end points, including change in pain visual analogue scale (0.4 vs 1.0; P = .83), treatment with morphine equivalents at 1 month (-7.8 vs 0.0; P = .35), change in quality of life at 1 month (SF-12 mental component: 1.3 vs -2.1; P = .44; and physical component: -0.2 vs 1.7; P = .54), or adverse events. The duration of response was shorter in the triamcinolone group (mean, 5.3 vs 0.6 mo; P = .01).

CONCLUSIONS

Triamcinolone does not increase pain relief or lengthen the effects of EUS-CPB.

Spinal cord stimulation for visceral pain from chronic pancreatitis

BACKGROUND AND OBJECTIVES

  Spinal cord stimulation (SCS) may reduce pain scores and improve function in patients with various chronic abdominal pain syndromes including chronic pancreatitis. Here described is a large clinical experience in SCS for severe chronic pancreatitis.

METHODS

  SCS was trialed in 30 patients with chronic pancreatitis. SCS trials lasted 7-14 days (median 9 days). SCS lead tips were mostly positioned at the T5 (N= 10) or T6 (N= 10) vertebral level.

RESULTS

  Twenty-four patients (80%) reported at least 50% pain relief on completion of the trial. Among these, pre-trial visual analog scale (VAS) pain scores averaged 8 ± 1.6 (standard deviation) and opioid use averaged 165 ± 120 mg morphine sulfate equivalents. During the trial, VAS pain scores decreased to 3.67 ± 2 cm (p < 0.001, Mann-Whitney Rank Sum Test) and opioid use decreased to 105 ± 101 mg morphine equivalent a day. Six patients failed the trial; one was lost to follow-up; in three patients after the implantation, the system had to be removed due to infection or lead migration; and 20 were followed for the whole year. For 20 patients followed for the whole year, VAS pain scores remained low (3.6 ± 2 cm; p < 0.001) at one year, as did opioid use (48.6 ± 58 mg morphine equivalents).

CONCLUSIONS

  SCS may be a useful therapeutic option for patients with severe visceral pain from chronic pancreatitis. Prospective trial is warranted.

Biopsychosocial assessment criteria for functional chronic visceral pain: a pilot review of concept and practice

Functional chronic visceral pain (FCVP) is one of the most common causes of morbidity in the general population. Pain perceived within the abdomen may occur due to a range of different mechanisms according to the organ and their afferent pathways. Advances in our understanding of the complexities of FCVP could lead to the exploitation of contemporary research in order to develop and utilize our understanding of neurobiological and psychobiological visceral mechanisms in a clinical setting. This progression, together with increasing amounts of epidemiological and gender based information concerning specific abdominal pain syndromes can allow us to develop assessment tools that go beyond disease only analysis and move toward a more comprehensive assessment model so that patients may have access to expert or multidisciplinary management sooner, rather than later. Based on current evidence, one must consider the main contributors to pain, whether it is nociceptive, neuropathic or psychosocial or as is common with FCVP, a combination of all three.

AIM

This comprehensive assessment model should encompass not only systematic evaluation for reliable communication, but should also progress toward idiographic diagnosis relating to the uniqueness of the patient. This model should be practical in a multidisciplinary setting, taking into account the multi-faceted nature of this presentation.

A randomized trial comparing endoscopic stenting to a sham procedure for chronic pancreatitis

Background A number of studies support the use of endoscopically placed pancreatic duct (PD) stents to decrease pain in chronic pancreatitis (CP). Nevertheless, flaws in study design have prevented experts from reaching a consensus.

Purpose (1) Evaluate the efficacy of PD stenting to ameliorate abdominal pain in patients with CP and ductal strictures; (2) evaluate the placebo response rate from sham endoscopic therapy; (3) compare pain medication usage, healthcare utilization, psychological distress, and quality of life before and after endoscopic stenting; (4) prospectively evaluate the durability of the response.

Methods Patients with typical abdominal pain, imaging confirmation of CP and endoscopic retrograde cholangiopancreatography (ERCP) confirmation of PD stricture will complete questionnaires to assess quality of life, psychological distress, pain intensity/unpleasantness, pain medication usage, and healthcare utilization. Enrolled patients will be randomized to ERCP with sphincterotomy and PD stenting versus sham procedure. Pain level and medication usage will be assessed weekly with telephone interviews. At 6—8 weeks, patients treated with stents will undergo stent removal; those randomized to the sham procedure without significant improvement (<50% reduction in pain score) will cross over to the treatment group; and those randomized to sham procedure who experienced improvement (>50% reduction) will be followed clinically. Patients will be followed in clinic or by phone biannually (up to 3 years). The primary endpoint is improvement in abdominal pain. The secondary endpoints are reduction in narcotic use, healthcare utilization, and work days missed; return to employment; improvement in quality of life and weight gain.

Results Proposed study.

Limitations Strict inclusion criteria may limit enrollment.

Conclusion The proposed study represents the first trial of endoscopic stenting for symptomatic CP and ductal strictures with a credible sham procedure, assessment of multiple dimensions of pain, and psychosocial factors. Clinical Trials 2009; 6: 455—463. http://ctj.sagepub.com

A prospective randomized trial of 1 versus 2 injections during EUS-guided celiac plexus block for chronic pancreatitis pain

BACKGROUND

The efficacy of 1-injection versus a 2-injections method of EUS-guided celiac plexus block (EUS-CPB) in patients with chronic pancreatitis is not known.

OBJECTIVE

To compare the clinical effectiveness and safety of EUS-CPB by using 1 versus 2 injections in patients with chronic pancreatitis and pain. The secondary aim is to identify factors that predict responsiveness.

DESIGN

A prospective randomized study.

INTERVENTIONS

EUS-CPB was performed by using bupivacaine and triamcinolone injected into 1 or 2 sites at the level of the celiac trunk during a single EUS-CPB procedure.

MAIN OUTCOME MEASUREMENTS

Duration of pain relief, onset of pain relief, and complications.

RESULTS

Fifty [corrected] subjects were enrolled (23 received 1 injection, 27 [corrected] received 2 injections). The median duration of pain relief in the 31 responders was 28 days (range 1-673 days). [corrected] Fifteen [corrected] of 23 (65%) [corrected] subjects who received 1 injection [corrected] had relief from pain compared with 16 of 27 (59%) [corrected] subjects who received 2 injections [corrected] (P = .67). [corrected] The median times to onset in the 1-injection and 2-injections groups were 21 and 14 days, respectively (P = .99). No correlation existed between duration of pain relief and time to onset of pain relief or onset within 24 hours. Age, sex, race, prior EUS-CPB, and smoking or alcohol history did not predict duration of pain relief.

LIMITATION

Telephone interviewers were not blinded.

CONCLUSIONS

There was no difference in duration of pain relief or onset of pain relief in subjects with chronic pancreatitis and pain when the same total amount of medication was delivered in 1 or 2 injections during a single EUS-CPB procedure. Both methods were safe.

Pain in chronic pancreatitis and pancreatic cancer

Chronic, debilitating abdominal pain is arguably the most important component of chronic pancreatitis, leading to significant morbidity and disability. Attempting to treat this pain, which is too often unsuccessful, is a frustrating experience for physician and patient. Multiple studies to improve understanding of the pathophysiology that causes pain in some patients but not in others have been performed since the most recent reviews on this topic. In addition, new treatment modalities have been developed and evaluated in this population. This review discusses new advances in neuroscience and the study of visceral pain mechanisms, as well as genetic factors that may play a role. Updates of established therapies, as well as new techniques used in addressing pain from chronic pancreatitis, are reviewed. Lastly, outcome measures, which have been highly variable in this field over the years, are addressed.