Acute Haemorrhagic Pancreatitis

Acute haemorrhagic pancreatitis is severe necrotising pancreatitis with haemorrhage into or around the pancreas, causing shock, retroperitoneal bleeding, flank and umbilical ecchymoses (Grey Turner and Cullen signs), and multi-organ failure.

Epidemiology. Acute pancreatitis occurs in about 30 to 40 cases in 100,000 people each year, and about 10 to 20% develop severe disease. Necrosis with organ failure carries mortality of 15 to 30%, and higher with infected necrosis.

Causes and associations. Gallstones, alcohol, hypertriglyceridaemia (over 11.3 mmol/L or 1000 mg/dL), hypercalcaemia, drugs (azathioprine, valproate, thiazides), post-endoscopic retrograde cholangiopancreatography, trauma, infection, autoimmune disease and genetic factors.

Classification. Mild (no organ failure), moderately severe (transient organ failure under 48 hours or local complications), severe (persistent organ failure over 48 hours).

Pathophysiology. Premature trypsinogen activation and autodigestion cause inflammation, microvascular injury and necrosis. Elastase and lipase damage vessel walls, giving haemorrhage and pseudoaneurysm formation (splenic, gastroduodenal, pancreaticoduodenal arteries). Systemic inflammation produces shock, ARDS and kidney injury.

Presentation is severe epigastric pain radiating to the back, vomiting, fever, tachycardia, hypotension, abdominal distension and guarding. Grey Turner sign (flank bruising) and Cullen sign (periumbilical bruising) appear after 24 to 72 hours and indicate retroperitoneal haemorrhage. Others are dyspnoea (ARDS, pleural effusion), oliguria, tetany (hypocalcaemia), and gastrointestinal bleeding.

Red flags.

• Shock, falling haemoglobin or flank and umbilical bruising.
• Organ failure persisting over 48 hours.
• Fever with new abdominal pain after 1 to 2 weeks (infected necrosis), or sudden bleeding (pseudoaneurysm).

Serum lipase or amylase over three times the upper limit of normal (lipase preferred), with the clinical picture and imaging. Full blood count, haematocrit, urea, creatinine, calcium, triglycerides, liver tests, glucose, lactate, gas, C-reactive protein (over 150 mg/L at 48 hours predicts severity), and cultures. Abdominal ultrasound for gallstones. Contrast enhanced CT after 72 hours (earlier if the diagnosis is doubtful, or bleeding is suspected) shows necrosis, haematoma and pseudoaneurysm; CT angiography when bleeding is suspected.

Differential diagnosis. Perforated ulcer, ruptured aortic aneurysm, mesenteric ischaemia, bowel obstruction, myocardial infarction, cholangitis and ruptured visceral artery aneurysm.

Fluid resuscitation. Early goal directed fluid with compound sodium lactate solution (preferred over 0.9% sodium chloride): 5 to 10 mL/kg/h initially (or a bolus of 10 to 20 mL/kg in shock) then 1.5 to 3 mL/kg/h, titrated to heart rate, mean arterial pressure, urine output (0.5 to 1 mL/kg/h), haematocrit and urea, with reassessment every 6 hours and avoidance of overload (risk of abdominal compartment syndrome and ARDS).

Haemorrhage. Transfuse red cells to a haemoglobin of 70 to 80 g/L, and correct coagulopathy. Contrast CT angiography, and transcatheter arterial embolisation for pseudoaneurysm or active bleeding (first choice). Surgery if embolisation fails or is unavailable.

Analgesia. Fentanyl 25 to 50 microgram IV, or morphine 2 to 4 mg IV, titrated, with an infusion or patient controlled analgesia. Paracetamol 1 g every 6 hours. Epidural for severe pain.

Nutrition. Enteral nutrition (nasogastric or nasojejunal) within 24 to 72 hours if tolerated. Parenteral nutrition only if enteral is not possible.

Antibiotics. Not given as prophylaxis. For infected necrosis (fever, gas in collections, positive cultures): meropenem 1 g IV every 8 hours, adjusted to renal function and cultures.

Biliary cause. Endoscopic retrograde cholangiopancreatography within 24 to 48 hours for cholangitis or persistent biliary obstruction. Cholecystectomy during the same admission for mild disease, and delayed until collections resolve in necrotising disease.

Hypertriglyceridaemia. Insulin infusion 0.1 to 0.3 units/kg/h with dextrose, and consider plasma exchange for triglycerides over 11.3 mmol/L with severe disease.

Organ support. Lung protective ventilation, renal replacement therapy, vasopressors and abdominal pressure monitoring (decompression for abdominal compartment syndrome).

Management of necrosis. Delay intervention for at least 4 weeks when possible, using a step up approach: percutaneous or endoscopic drainage, then minimally invasive necrosectomy if needed.

Monitoring. Vital signs hourly in shock, urine output, haemoglobin every 4 to 6 hours, calcium, glucose, bladder pressure, organ failure scoring daily and repeat imaging for deterioration.

Referral and escalation. Intensive care, gastroenterology, interventional radiology and hepatobiliary surgery at once.

Special groups. In pregnancy, check triglycerides and gallstones, and involve obstetrics. In alcohol use disorder, give thiamine 100 mg IV daily and treat withdrawal.