Alcohol-Induced Pancreatitis

Acute pancreatitis caused by alcohol, usually after 5 to 10 years of heavy drinking (more than 4 to 5 drinks a day (about 10 g of alcohol each), or more than 50 g of alcohol daily). Only about 5 to 10% of heavy drinkers develop pancreatitis, so genetic and other factors contribute.

• Accounts for about 30% of acute pancreatitis (higher in men aged 30 to 50 years); smoking multiplies the risk; about 20 to 30% of patients have recurrent attacks and develop chronic pancreatitis.
• Mechanism: alcohol and its metabolites (fatty acid ethyl esters, acetaldehyde) sensitise acinar cells to injury, cause premature enzyme activation, increase protein plug formation in ducts and sphincter of Oddi spasm, and induce pancreatic stellate cell fibrosis.
• Severity: mostly mild to moderate; severe disease with necrosis in about 10 to 15%, with mortality of about 2 to 5% overall and 20 to 40% in severe cases.
• Alcohol withdrawal may complicate the admission within 6 to 48 hours.

Epigastric pain radiating to the back, nausea and vomiting, usually 6 to 72 hours after a heavy drinking bout; fever, tachycardia, abdominal tenderness.

• Signs of chronic alcohol use: parotid enlargement, spider naevi, palmar erythema, hepatomegaly, tremor, malnutrition.
• Signs of withdrawal: tremor, sweating, agitation, hallucinations, seizures, delirium tremens.
• Differential diagnosis: gallstone pancreatitis, hypertriglyceridaemic pancreatitis, perforated ulcer, alcoholic hepatitis, alcoholic gastritis, mesenteric ischaemia, bowel obstruction, inferior myocardial infarction, diabetic ketoacidosis (alcoholic ketoacidosis).
• Complications: pancreatic necrosis and infection, pseudocyst, pancreatic ascites or pleural effusion, splenic vein thrombosis with varices, diabetes (type 3c), exocrine insufficiency, chronic pancreatitis with pain, pancreatic cancer risk, malnutrition, alcohol withdrawal and Wernicke encephalopathy.

Tests:

• Lipase of more than 3 times the upper limit of normal (amylase may be normal in recurrent alcohol related disease).
• Full blood count (macrocytosis), urea, creatinine, electrolytes (including magnesium and phosphate), calcium, glucose, and triglycerides.
• Liver tests (raised gamma glutamyl transferase, aspartate aminotransferase greater than alanine aminotransferase), C-reactive protein, and arterial gas.
• Exclude gallstones with ultrasound, and exclude other causes of pancreatitis (triglycerides, calcium, drugs).
• Contrast CT at 72 hours or more for suspected necrosis, or when the diagnosis is uncertain; features of chronic pancreatitis include calcification, ductal dilatation and atrophy.
• Alcohol history (quantity, duration, previous withdrawal, seizures), validated screening questionnaire, and blood alcohol; assess for liver disease (ultrasound, platelet count, INR) and malnutrition.
• Later: faecal elastase (less than 200 micrograms/g indicates exocrine insufficiency), HbA1c.

Fluid resuscitation: lactated Ringer solution 5 to 10 mL/kg/hour for 12 to 24 hours, reassessing every 6 hours (urine output more than 0.5 mL/kg/hour, mean arterial pressure 65 to 85 mmHg, falling urea); avoid overload.

• Thiamine before glucose: thiamine 200 to 300 mg IV three times daily for 3 to 5 days (for example 2 pairs of high-potency B vitamin ampoules three times daily), then thiamine 100 mg orally three times daily.
• Folic acid 5 mg daily; correct magnesium (magnesium sulfate 2 g IV over 20 minutes), potassium and phosphate.
• Analgesia:
  • Paracetamol 1 g every 6 hours (maximum 3 g daily in chronic alcohol use).
  • Morphine 2 to 5 mg IV every 2 to 4 hours as needed, or fentanyl 25 to 50 micrograms IV or hydromorphone 0.5 to 1 mg IV.
  • Patient controlled analgesia; epidural for refractory pain; higher opioid needs are common but watch for sedation.
• Alcohol withdrawal prevention and treatment:
  • Chlordiazepoxide 20 to 30 mg orally four times daily on day 1, reducing by 20% daily over 5 to 7 days.
  • Or diazepam 10 to 20 mg orally every 1 to 2 hours until calm for severe symptoms (maximum 120 mg in 24 hours), with lower doses in liver disease (lorazepam 1 to 2 mg every 4 to 6 hours).
  • Seizures: lorazepam 4 mg IV, repeated once after 10 minutes.
  • Delirium tremens: diazepam 10 mg IV every 5 to 10 minutes until sedated, intensive care, and haloperidol 2.5 to 5 mg for hallucinations only after benzodiazepines.
• Nutrition: oral low fat diet within 24 hours when pain allows.
• Enteral feeding (30 kcal/kg/day) if intake fails after 48 to 72 hours, with refeeding precautions (start at 10 to 20 kcal/kg/day, give thiamine first, and monitor phosphate, potassium and magnesium daily for 3 days).
• No prophylactic antibiotics; antibiotics for infected necrosis: meropenem 1 g IV every 8 hours for 2 to 4 weeks guided by cultures; enoxaparin 40 mg SC daily for thromboprophylaxis; oxygen and organ support as needed.
• Collections and necrosis: delay intervention until about 4 weeks, then endoscopic transluminal drainage and necrosectomy for infection or obstruction.
• Alcohol cessation (the key to prevent recurrence and progression):
  • Brief intervention before discharge and referral to addiction services; counselling.
  • Naltrexone 50 mg daily (avoid with opioid use and in hepatic impairment) or acamprosate 666 mg three times daily (333 mg three times daily if creatinine clearance is 30 to 50 mL/min; avoid if less than 30 mL/min) once abstinent.
  • Baclofen 10 mg three times daily (evidence limited) in liver disease; avoid disulfiram.
  • Smoking cessation (varenicline 0.5 mg daily for 3 days, 0.5 mg twice daily for 4 days, then 1 mg twice daily for 12 weeks).
• Chronic complications:
  • Exocrine insufficiency: pancrelipase 25,000 to 50,000 units with meals and 10,000 to 25,000 units with snacks, with omeprazole 20 mg daily when response is poor.
  • Diabetes: insulin or metformin 500 mg daily to 1 g twice daily with caution in alcohol misuse.
  • Chronic pain: paracetamol, then a tricyclic or gabapentin 300 mg at night titrated to 900 mg three times daily, then opioids sparingly; endoscopic or surgical drainage for ductal obstruction.
  • Vitamin and bone care: vitamin D 800 to 2000 units daily, calcium, and fat soluble vitamin checks.
• Special groups:
  • Pregnancy: rare, stop alcohol, thiamine, fluids, avoid benzodiazepines at term if possible and plan neonatal monitoring.
  • Elderly: lower sedative doses, thiamine, delirium risk.
  • Hepatic impairment: use lorazepam or oxazepam for withdrawal, avoid paracetamol over 2 g in decompensated cirrhosis.
  • Renal impairment: adjust acamprosate, avoid NSAIDs.
  • Young adults: screen for genetic and other causes.
• Red flags: seizures, delirium tremens, persistent organ failure, necrosis with fever, bleeding, confusion or ataxia (Wernicke encephalopathy: give thiamine 500 mg IV three times daily for 2 to 3 days), ascites.
• Follow-up: clinic at 2 to 4 weeks, then every 3 to 6 months. Liver tests, glucose, and nutrition review; imaging at 6 weeks if collections. Fat soluble vitamins and bone density yearly in chronic disease; surveillance for diabetes and for pancreatic cancer if symptoms change.