Infected pancreatic necrosis
Infected pancreatic necrosis is secondary bacterial or fungal infection of devitalized pancreatic or peripancreatic tissue, usually one to four weeks into severe acute pancreatitis. Diagnosis rests on gas within a necrotic collection on CT or a positive culture from image-guided aspiration. First-line treatment is a necrosis-penetrant carbapenem such as meropenem plus staged, minimally invasive drainage using the step-up approach.
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What this article covers
- Overview
What it is: Infected pancreatic necrosis is secondary bacterial, or occasionally fungal, infection of devitalized pancreatic parenchyma or peripancreatic fat formed during necrotizing acute pancreatitis.
- Epidemiology
Incidence within pancreatitis: Necrotizing pancreatitis complicates roughly 10 to 20% of acute pancreatitis episodes, and a substantial minority of those collections become infected, most often in the second and third weeks.
- Risk factors
Extent of necrosis: Necrosis involving more than 30% of the gland carries a materially higher infection risk than limited necrosis.
- Pathophysiology
Initiating injury: Premature intra-acinar activation of trypsinogen triggers autodigestion and a local cytokine cascade (tumor necrosis factor, interleukin-6), producing microvascular injury and…
- Clinical features
Timing and fever pattern: Fever, tachycardia, and deterioration typically emerge 1 to 4 weeks after onset; a new or persistent fever in a patient already known to have necrosis, rather than the…
- Differential diagnosis
Sterile pancreatic necrosis: Fever and systemic inflammation from necrosis alone without bacterial invasion, distinguished by a negative culture on image-guided aspiration and no gas on imaging.
- Diagnosis
What establishes the diagnosis: Infected pancreatic necrosis is confirmed by a positive Gram stain or culture obtained by CT-guided fine-needle aspiration (FNA) of the necrosis, or by gas visualized…
- Management
First, stabilize and dose empirically: For a septic or unstable patient, resuscitate immediately with intravenous fluids and vasopressors per standard sepsis protocols, and give meropenem 1 g IV…
- Complications
Septic shock and multiorgan failure: The most immediate threat, driving most deaths after the first week when source control is delayed.
- Prognosis
Overall mortality: Mortality for acute pancreatitis overall is 5 to 10%, but severe acute pancreatitis, the category into which infected necrosis nearly always falls, carries mortality that may approach 50%.
- Prevention
Avoid prophylactic antibiotics in sterile necrosis: Routine prophylaxis does not prevent progression to infection and should not be given regardless of necrosis size.
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Related articles
- Acute pancreatitis
Acute pancreatitis is acinar-cell autodigestion and inflammation of the pancreas, most often from gallstones or alcohol, diagnosed by the revised Atlanta criteria and graded mild, moderately severe, or severe by organ failure. Management centers on early goal-directed lactated Ringer's resuscitation, analgesia, early enteral feeding, and timed ERCP for gallstone pancreatitis with cholangitis, reserving antibiotics for confirmed infected necrosis.
- Chronic pancreatitis
Chronic pancreatitis is irreversible fibro-inflammatory destruction of the pancreas that produces abdominal pain along with exocrine and endocrine insufficiency, most often from long-term alcohol use in adults and cystic fibrosis in children. Diagnosis rests on CT or MRI showing calcifications and ductal change, and management combines alcohol and tobacco cessation, staged analgesia, pancreatic enzyme replacement, and endoscopic or surgical drainage for ductal obstruction.
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A pancreatic pseudocyst is an encapsulated, fluid-filled collection lacking solid debris that forms more than 4 weeks after interstitial acute or chronic pancreatitis. Diagnosis rests on contrast-enhanced CT showing a well-defined wall around fluid. Most resolve spontaneously; endoscopic transmural drainage is reserved for symptomatic, infected, or enlarging pseudocysts.
- Acute cholangitis
Acute cholangitis is a bacterial infection of an obstructed biliary tree, classically presenting as Charcot triad of fever, right upper quadrant pain, and jaundice and progressing to septic shock when drainage is delayed. Diagnosis follows the Tokyo Guidelines and severity grade, and treatment combines prompt broad-spectrum antibiotics with biliary drainage, most often by ERCP.
- Cholelithiasis
Cholelithiasis is the presence of gallstones in the gallbladder, most often cholesterol stones from bile supersaturation, and is asymptomatic in most patients. Symptomatic disease presents as biliary colic, self-limited postprandial right upper quadrant pain without fever, diagnosed by right upper quadrant ultrasound and treated with elective laparoscopic cholecystectomy.
- Sepsis
Sepsis is life-threatening organ dysfunction caused by a dysregulated host response to infection, identified by an acute rise in SOFA score of 2 points or more in a patient with known or suspected infection. Survival depends on recognizing the pattern early and completing the hour-1 bundle: lactate, blood cultures before antibiotics, broad-spectrum antibiotics such as cefepime 2 g IV every 8 hours, and 30 mL/kg crystalloid for hypotension or a lactate of 4 mmol/L or higher.