Effects of the peripherally acting μ-opioid receptor antagonist methylnaltrexone on acute pancreatitis severity: study protocol for a multicentre double-blind randomised placebo-controlled interventional trial, the PAMORA-AP trial

No Effect of Methylnaltrexone on Acute Pancreatitis Severity: A Multicenter Randomized Controlled Trial

INTRODUCTION

Opioids used to manage severe pain in acute pancreatitis (AP) might exacerbate the disease through effects on gastrointestinal and immune functions. Methylnaltrexone, a peripherally acting µ-opioid receptor antagonist, may counteract these effects without changing analgesia.

METHODS

This double-blind, randomized, placebo-controlled trial included adult patients with AP and systemic inflammatory response syndrome at 4 Danish centers. Patients were randomized to receive 5 days of continuous intravenous methylnaltrexone (0.15 mg/kg/d) or placebo added to the standard of care. The primary end point was the Pancreatitis Activity Scoring System score after 48 hours of treatment. Main secondary outcomes included pain scores, opioid use, disease severity, and mortality.

RESULTS

In total, 105 patients (54% men) were randomized to methylnaltrexone (n = 51) or placebo (n = 54). After 48 hours, the Pancreatitis Activity Scoring System score was 134.3 points in the methylnaltrexone group and 130.5 points in the placebo group (difference 3.8, 95% confidence interval [CI] -40.1 to 47.6; P = 0.87). At 48 hours, we found no differences between the groups in pain severity (0.0, 95% CI -0.8 to 0.9; P = 0.94), pain interference (-0.3, 95% CI -1.4 to 0.8; P = 0.55), and morphine equivalent doses (6.5 mg, 95% CI -2.1 to 15.2; P = 0.14). Methylnaltrexone also did not affect the risk of severe disease (8%, 95% CI -11 to 28; P = 0.38) and mortality (6%, 95% CI -1 to 12; P = 0.11). The medication was well tolerated.

DISCUSSION

Methylnaltrexone treatment did not achieve superiority over placebo for reducing the severity of AP.

Value of serum CRP and IL-6 Assays combined with Pancreatitis activity scoring system for assessing the severity of patients with acute pancreatitis

Objective

To evaluate the accuracy of serum CRP and IL-6 assays combined with the pancreatitis activity scoring system (PASS) in assessing the severity of patients with acute pancreatitis (AP).

Methods

This was a retrospective study of 223 patients with AP admitted to Baoding Lianchi District People's Hospital between February 2021 and 2023. They were classified into three categories: mild AP (MAP), moderate severe AP (MSAP) and severe AP (SAP). The differences, accuracy and sensitivity of the individual assays, and the three in combination, were compared and analysed in the three groups.

Results

PASS scores, IL-6 and CRP levels were significantly higher in the SAP and MSAP groups compared to those in the MAP group, with statistically significant differences between the three groups. Multi-factorial logistic regression analysis suggested that PASS, IL-6 and CRP were correlated indicators of AP severity. The combination of the three assays was higher than that of the PASS score, IL-6 and CRP alone, suggesting optimal diagnostic efficacy when the three assays were combined. Moreover, the levels of PASS score, IL-6 and CRP showed a positive correlation with the degree of disease severity.

Conclusions

The serum CRP, IL-6 and PASS scores were significantly elevated in AP patients and showed a positive correlation with disease severity, all of which are beneficial for the diagnosis of AP. PASS is superior to CRP and IL-6 in the assessment of AP. The combination of the three assays can achieve a far superior diagnostic efficacy to that of the individual index assays.

Exploring the value of early laboratory indicators combined with pancreatitis activity scoring system in assessing the severity and prognosis of acute pancreatitis

Objective

To investigate the value of early laboratory indicators combined with the pancreatitis activity scoring system in assessing the severity and prognosis of acute pancreatitis (AP).

Methods

This is a retrospective study. A total of 160 patients with AP admitted to the Affiliated Hospital of Hebei University from February 2021 to February 2023 were enrolled and classified into three categories: mild acute pancreatitis (MAP), moderate severe acute pancreatitis (MSAP), and severe acute pancreatitis (SAP), with 80 cases with MAP and MSAP as the control group and 80 cases with SAP as the experimental group. The differences of inflammatory markers, blood routine, biochemical markers, coagulation markers and PASS score within 24 hours after admission were compared between the two groups, and independent risk factors for predicting AP severity were analyzed. Moreover, the diagnostic efficacy and prognostic value of independent risk factors were evaluated.

Results

The PASS score as well as CRP, PCT, IL-6, WBC, N, AST, DD and PT were higher in the experimental group than in the control group. Logistic regression analysis suggested that PASS, IL-6, PCT and WBC were independent risk factors for predicting severity of AP. In addition, PASS had the highest diagnostic efficacy.

Conclusion

Early elevation of PASS, IL-6, PCT and WBC in patients suffering from AP is of great significance in predicting SAP. PASS score combined with IL-6, PCT and WBC has important value in evaluating the severity and prognosis of AP.

Acute Pancreatitis: Diagnosis and Treatment

Acute pancreatitis is a common indication for hospital admission, increasing in incidence, including in children, pregnancy and the elderly. Moderately severe acute pancreatitis with fluid and/or necrotic collections causes substantial morbidity, and severe disease with persistent organ failure causes significant mortality. The diagnosis requires two of upper abdominal pain, amylase/lipase ≥ 3 ×upper limit of normal, and/or cross-sectional imaging findings. Gallstones and ethanol predominate while hypertriglyceridaemia and drugs are notable among many causes. Serum triglycerides, full blood count, renal and liver function tests, glucose, calcium, transabdominal ultrasound, and chest imaging are indicated, with abdominal cross-sectional imaging if there is diagnostic uncertainty. Subsequent imaging is undertaken to detect complications, for example, if C-reactive protein exceeds 150 mg/L, or rarer aetiologies. Pancreatic intracellular calcium overload, mitochondrial impairment, and inflammatory responses are critical in pathogenesis, targeted in current treatment trials, which are crucially important as there is no internationally licenced drug to treat acute pancreatitis and prevent complications. Initial priorities are intravenous fluid resuscitation, analgesia, and enteral nutrition, and when necessary, critical care and organ support, parenteral nutrition, antibiotics, pancreatic exocrine and endocrine replacement therapy; all may have adverse effects. Patients with local complications should be referred to specialist tertiary centres to guide further management, which may include drainage and/or necrosectomy. The impact of acute pancreatitis can be devastating, so prevention or reduction of the risk of recurrence and progression to chronic pancreatitis with an increased risk of pancreas cancer requires proactive management that should be long term for some patients.