ENDoscopic Assessment in Acute PANcreatitis Study (ENDOPAN Study)

Acute pancreatitis is one of the most common acute gastrointestinal conditions requiring hospital admission and is associated with a highly variable clinical course. Although most patients develop a mild and self-limiting form of the disease, a clinically important proportion progress to moderately severe or severe acute pancreatitis, with local complications, systemic inflammatory response, organ failure, prolonged hospitalization, need for invasive interventions, and increased mortality. Early identification of patients at risk of an unfavorable course remains a major clinical challenge. Existing prognostic systems and laboratory markers are useful, but they do not fully capture all clinically relevant determinants of disease progression, particularly those related to early upper gastrointestinal mucosal injury, gastric and duodenal involvement, and local inflammatory response in the upper gastrointestinal tract.

The revised Atlanta classification provides a widely accepted framework for the diagnosis and severity assessment of acute pancreatitis. According to this classification, acute pancreatitis is diagnosed when at least two of the following three criteria are present: typical abdominal pain, serum amylase or lipase activity at least three times the upper limit of normal, and imaging findings consistent with acute pancreatitis. Disease severity is classified as mild, moderately severe, or severe. Mild acute pancreatitis is characterized by the absence of organ failure and local or systemic complications. Moderately severe acute pancreatitis is associated with transient organ failure lasting less than 48 hours and/or local or systemic complications without persistent organ failure. Severe acute pancreatitis is defined by persistent organ failure lasting longer than 48 hours, which may involve one or multiple organ systems.

Despite this classification, early prediction of clinical course remains imperfect. Laboratory parameters such as C-reactive protein, white blood cell count, blood urea nitrogen, creatinine, hematocrit, procalcitonin, and biochemical markers of cholestasis may be associated with severity, but their predictive performance varies. Radiological evaluation, particularly contrast-enhanced computed tomography, plays a key role in detecting pancreatic necrosis and local complications; however, early computed tomography may underestimate evolving changes, and the optimal timing for imaging is usually several days after symptom onset or admission. Clinical scores are available, but they can be complex, may require repeated measurements, and may not sufficiently reflect local upper gastrointestinal effects of the disease.

Upper gastrointestinal symptoms are common in acute pancreatitis. Patients frequently present with nausea, vomiting, epigastric pain, feeding intolerance, ileus, gastroesophageal reflux symptoms, or signs of gastric outlet dysfunction. The stomach and duodenum are anatomically close to the pancreas and may be affected by inflammatory edema, local vascular disturbances, impaired motility, stress-related mucosal injury, duodenal compression, and systemic inflammatory changes. Endoscopic abnormalities such as gastritis, duodenitis, erosions, ulcerations, mucosal edema, hemorrhagic lesions, bile reflux, esophagitis, or signs of impaired gastric emptying may therefore reflect both local and systemic consequences of acute pancreatitis. However, early upper gastrointestinal endoscopy is not routinely performed in all patients with acute pancreatitis, and the prognostic significance of early endoscopic mucosal changes remains insufficiently defined.

Preliminary retrospective observations from the study center suggest that upper gastrointestinal mucosal abnormalities are frequent in patients hospitalized with acute pancreatitis and may be associated with disease severity, inflammatory burden, Helicobacter pylori status, and the subsequent clinical course. These observations provide the rationale for a prospective study designed to systematically evaluate early endoscopic findings in a predefined cohort of adult patients with acute pancreatitis. A prospective design will allow standardized timing of endoscopy, uniform collection of clinical and laboratory data, systematic assessment of disease severity, and evaluation of the relationship between mucosal injury and clinically meaningful outcomes.

This study is a prospective observational cohort study conducted in adult patients hospitalized due to acute pancreatitis. The study is designed to assess whether early upper gastrointestinal endoscopic findings are associated with the severity and clinical course of acute pancreatitis. The study will be performed at a single academic clinical center with experience in the diagnosis and treatment of acute pancreatitis and access to surgical, endoscopic, radiological, intensive care, and laboratory facilities. The study does not involve random allocation to treatment groups and does not test an investigational medicinal product or device. All therapeutic decisions will remain at the discretion of the treating physicians and will follow current clinical standards and local institutional protocols. The study intervention consists of protocol-defined diagnostic upper gastrointestinal endoscopy and systematic prospective collection of clinical, laboratory, imaging, microbiological, and outcome data.

The target study population consists of adult patients admitted to the study center with a diagnosis of acute pancreatitis according to the revised Atlanta criteria. Patients will be screened after admission. Eligibility will be confirmed by the study team based on clinical presentation, laboratory results, imaging when available, and safety considerations for endoscopy. Written informed consent will be obtained before enrollment and before any study-specific procedure is performed. The study will include patients with different etiologies of acute pancreatitis, including biliary, alcoholic, hypertriglyceridemic, post-endoscopic retrograde cholangiopancreatography-related, idiopathic, and other less common causes, provided that inclusion and exclusion criteria are met.

The planned sample size is 200 patients. This number was selected to provide a clinically meaningful prospective cohort allowing evaluation of the prevalence and severity of early mucosal abnormalities and their association with disease severity categories and important clinical outcomes. The enrollment period is expected to last approximately two and a half years, depending on the number of eligible patients, consent rate, safety of endoscopy in the early phase of disease, and logistical feasibility. The study start, primary completion, and final completion dates will be reported as anticipated dates and updated as necessary during the conduct of the study.

The primary objective of the study is to evaluate the association between early upper gastrointestinal mucosal abnormalities and the severity of acute pancreatitis according to the revised Atlanta classification. Mucosal abnormalities will be assessed during upper gastrointestinal endoscopy performed within 24 to 48 hours from hospital admission whenever clinically and logistically feasible. Endoscopic findings will be described in a structured manner, including the presence, location, type, and severity of lesions in the esophagus, stomach, and duodenum. Particular attention will be paid to gastric and duodenal mucosal edema, erythema, erosions, ulcerations, hemorrhagic lesions, bile reflux, duodenitis, signs of duodenal compression or narrowing, retained gastric contents, and other abnormalities considered relevant by the endoscopist.

Secondary objectives include assessment of the association between endoscopic findings and transient or persistent organ failure, systemic inflammatory response, local complications of acute pancreatitis, need for intensive care unit admission, need for endoscopic, radiological, or surgical interventions, nutritional tolerance, length of hospital stay, in-hospital mortality, inflammatory marker dynamics, imaging findings, and Helicobacter pylori status when assessed. The study will also explore whether the severity and distribution of upper gastrointestinal mucosal abnormalities add clinically useful information beyond standard laboratory, clinical, and imaging parameters.

Upper gastrointestinal endoscopy will be performed by experienced endoscopists according to local practice and safety standards. The planned timing of the first endoscopy is within 24 to 48 hours from hospital admission. The procedure will be performed only when the patient's clinical condition allows safe examination. Endoscopy will not be performed or will be postponed in patients with hemodynamic instability, severe respiratory compromise, inability to provide informed consent, or any condition judged by the treating physician or investigator to create an unacceptable procedural risk. The decision regarding sedation, monitoring, and procedural precautions will follow institutional standards and individual patient risk assessment. The procedure will be diagnostic. Therapeutic intervention during endoscopy will not be part of the study protocol, but if an urgent clinically indicated intervention is required, it will be performed according to standard medical care and documented.

In patients who develop moderately severe or severe acute pancreatitis, or in patients with clinically significant early endoscopic findings, a follow-up upper gastrointestinal endoscopy may be performed before discharge if it is clinically safe and feasible. The purpose of the follow-up endoscopy is to evaluate the evolution, persistence, improvement, or worsening of mucosal abnormalities during the same hospitalization. The follow-up examination is not mandatory for all participants and will depend on disease severity, clinical condition, consent, and investigator judgment. Reasons for not performing a follow-up endoscopy will be documented when applicable.

Clinical data will be collected prospectively from admission through discharge. Baseline data will include age, sex, body mass index when available, comorbidities, Charlson comorbidity index or individual comorbidity profile, current medications, history of previous acute pancreatitis, history of gallstones or biliary tract disease, alcohol use history when available, smoking status when available, previous endoscopic retrograde cholangiopancreatography, previous abdominal surgery, and other relevant clinical variables. The etiology of acute pancreatitis will be classified according to available clinical, laboratory, imaging, and procedural data. Biliary pancreatitis will be considered in the presence of gallstones, common bile duct stones, biliary sludge, cholestatic laboratory abnormalities, or imaging evidence suggesting biliary obstruction. Alcoholic pancreatitis will be assessed according to clinical history. Hypertriglyceridemic pancreatitis will be identified based on serum triglyceride concentration and clinical context. Post-endoscopic retrograde cholangiopancreatography pancreatitis will be classified according to accepted clinical definitions. Cases without an identifiable cause after standard evaluation will be classified as idiopathic.

Laboratory data will be recorded at baseline and during hospitalization according to clinical availability. These may include serum amylase, lipase, C-reactive protein, white blood cell count, hemoglobin, hematocrit, platelet count, creatinine, urea or blood urea nitrogen, electrolytes, glucose, calcium, bilirubin, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, albumin, total protein, lactate dehydrogenase, coagulation parameters, triglycerides, arterial blood gas parameters when available, procalcitonin when available, and other clinically relevant markers. The timing of key laboratory values will be d

• Percentage of Participants With Early Upper Gastrointestinal Mucosal Abnormalities [Срок оценки: Within 24-48 hours from hospital admission]