Acute pancreatitis

Introduction to Acute Pancreatitis

According to Love and Bailey’s “A Short Practice of Surgery”, acute pancreatitis is defined as an acute inflammatory condition of the pancreas with varying involvement of other regional tissues or remote organ systems.

Key Epidemiological Facts

Incidence: 5-80 cases per 100,000 population annually
Mild edematous pancreatitis accounts for 80% of cases
Severe necrotizing pancreatitis occurs in 20% of cases
Overall mortality: 5-10% (higher in severe cases)

Etiology and Risk Factors

Common Causes (According to Love & Bailey)

Etiology	Frequency	Remarks
Gallstones	40-50%	Most common cause worldwide.
Alcohol	25-35%	More common in males, chronic consumption.
Idiopathic	10-20%	No identifiable cause after investigation.
Hypertriglyceridemia	1-4%	Triglycerides >1000 mg/dL
ERCP-induced	3-5%	Iatrogenic, usually mild.
Drug-induced	1-2%	Azathioprine, thiazides, steroids, etc.
Trauma	1-2%	Blunt abdominal trauma, surgical injury.

Less Common Causes

Infections (mumps, coxsackievirus, CMV)
Autoimmune pancreatitis
Hypercalcemia
Pancreatic duct obstruction
Hereditary pancreatitis
Scorpion venom (Tityus trinitatis)

Pathophysiology

Key Mechanisms According to Love & Bailey

1. Autodigestion Theory

The fundamental pathological process involves premature activation of pancreatic enzymes within the pancreas itself:

Trypsinogen → Trypsin (key activating enzyme)
Activation of other proenzymes (phospholipase A2, elastase)
Digestion of pancreatic parenchyma and peripancreatic tissues
Release of inflammatory mediators

2. Inflammatory Cascade

Activation of complement system
Release of cytokines (TNF-α, IL-1, IL-6, IL-8)
Activation of coagulation system
Systemic inflammatory response syndrome (SIRS)

3. Gallstone Pathogenesis

“Common channel” hypothesis:

Gallstone impacts at ampulla of Vater
Obstruction of pancreatic duct
Increased intraductal pressure
Activation of pancreatic enzymes
Pancreatic injury and inflammation

Clinical Features

Cardinal Symptoms

Abdominal pain: Severe, constant, epigastric radiating to back
Nausea and vomiting: Profuse, not relieving pain
Fever: Low-grade in mild cases, high in severe cases
Abdominal distension: Due to ileus

Physical Examination Findings

Finding	Description	Significance
Abdominal tenderness	Epigastric with guarding	Localized or generalized peritonitis
Cullen’s sign	Periumbilical bruising	Indicates hemorrhagic pancreatitis
Grey Turner’s sign	Flank bruising	Indicates hemorrhagic pancreatitis
Hypotension	Systolic BP <90 mmHg	Severe pancreatitis with third spacing
Tachycardia	Heart rate >100/min	Systemic inflammatory response
Tachypnea	Respiratory rate >20/min	Pleural effusion or ARDS

Diagnosis and Investigations

Diagnostic Criteria (Atlanta Classification)

Requires at least 2 of the following 3 features:

Abdominal pain consistent with acute pancreatitis
Serum amylase or lipase >3 times upper limit of normal
Characteristic findings on imaging (CT, MRI, or US)

Laboratory Investigations

Test	Findings	Clinical Significance
Serum amylase	Elevated (>3× normal)	Rises in 2-12 hours, normalizes in 3-5 days
Serum lipase	Elevated (>3× normal)	More specific, remains elevated longer
Complete blood count	Leukocytosis	Marked elevation in severe cases
Liver function tests	Elevated bilirubin/ALP	Suggests gallstone etiology
Serum calcium	Hypocalcemia	Prognostic marker, indicates severity
CRP	Elevated	Best laboratory marker of severity

Imaging Studies

Abdominal ultrasound: First-line for detecting gallstones, assessing biliary tree
Contrast-enhanced CT: Gold standard for diagnosis and assessing severity
MRI/MRCP: Excellent for detecting ductal abnormalities, subtle necrosis
Endoscopic ultrasound: For detecting microlithiasis, tumors

Severity Assessment

Ranson’s Criteria (at admission and 48 hours)

At Admission	During Initial 48 Hours
Age >55 years	Hct decrease >10%
WBC >16,000/mm³	BUN increase >5 mg/dL
Blood glucose >200 mg/dL	Serum calcium <8 mg/dL
LDH >350 IU/L	Arterial PO₂ <60 mmHg
AST >250 IU/L	Base deficit >4 mEq/L
	Fluid sequestration >6 L

Interpretation: Mortality: 0-2 criteria = 2%, 3-4 criteria = 15%, 5-6 criteria = 40%, >6 criteria = 100%

Management Principles

Initial Management (According to Love & Bailey)

Resuscitation:
- Aggressive IV fluid therapy (crystalloids)
- Monitor urine output (target >0.5 mL/kg/hr)
- Correct electrolyte abnormalities
Pain Management:
- Opioids (preferably patient-controlled analgesia)
- Avoid morphine (may cause sphincter of Oddi spasm)
Nutritional Support:
- Mild cases: NPO initially, advance as tolerated
- Severe cases: Enteral nutrition (nasojejunal preferred)
- Parenteral nutrition if enteral route not feasible
Monitoring:
- Vital signs, fluid balance, organ function
- Serial clinical assessment and laboratory tests

Specific Treatments

Gallstone Pancreatitis

Early ERCP (within 72 hours) for cholangitis or persistent biliary obstruction
Cholecystectomy during same admission for mild cases
Delayed cholecystectomy (after resolution) for severe cases

Severe Acute Pancreatitis

ICU admission for monitoring and organ support
Antibiotics for infected necrosis (proven or suspected)
Minimally invasive or open necrosectomy for infected necrosis not responding to antibiotics

Complications of Acute Pancreatitis

Local Complications

Complication	Timing	Management
Acute peripancreatic fluid collection	<4 weeks	Conservative, drainage if symptomatic
Pancreatic pseudocyst	>4 weeks	Drainage if >6cm or symptomatic
Acute necrotic collection	<4 weeks	Antibiotics if infected, drainage
Walled-off necrosis	>4 weeks	Drainage if infected or symptomatic
Pancreatic abscess	>4 weeks	Percutaneous or surgical drainage

Systemic Complications

Respiratory: Pleural effusion, ARDS, atelectasis
Cardiovascular: Hypotension, arrhythmias, myocardial depression
Renal: Acute kidney injury, renal failure
Hematological: DIC, thrombocytopenia
Metabolic: Hypocalcemia, hyperglycemia, hypertriglyceridemia
Gastrointestinal: Ileus, portal vein thrombosis, colonic necrosis

References

Love, R. J. M., & Bailey, H. (Latest Edition). A Short Practice of Surgery. London: Edward Arnold.
Chapter on Pancreatic Diseases in Love & Bailey’s textbook
American Gastroenterological Association Guidelines on Acute Pancreatitis
International Association of Pancreatology Guidelines
Atlanta Classification of Acute Pancreatitis (Revised)

Key Learning Points from Love & Bailey

“The management of acute pancreatitis requires a multidisciplinary approach with careful monitoring, aggressive fluid resuscitation, and timely intervention for complications.”
- Love & Bailey, A Short Practice of Surgery

Important Clinical Pearls

Early aggressive fluid resuscitation improves outcomes
Contrast-enhanced CT is the gold standard for diagnosis and staging
Enteral nutrition is preferred over parenteral nutrition
Infected pancreatic necrosis requires drainage and/or debridement
Cholecystectomy should be performed during the same admission for gallstone pancreatitis

This educational blog is based on the surgical textbook “A Short Practice of Surgery” by Love and Bailey.

For medical professionals and students only. Always consult current guidelines and local protocols.

Most common cause of acute pancreatitis is gall stones.
2nd most common cause is alcohol.
Other cause include Secondary to trauma.
Iatrogenic causes e.g. post-ERCP(Endoscopic Retrograde CholangioPancreaticography).
Pathogenesis is Explained by Co-localisation theory, In which enzymes of pancreas activate inside it and start causing damage to pancreas.
Clinical features include pain in epigastric region, which relieves on bending.
Signs include grey turner sign, cullen sign and fox sign.
Diagnostic criteria involves any 2 positive out of imaging suggestive, three fold rise in serum amylase and pain in right epigastric region associated with acute pancreatitis.
Investigation of choice is (CECT)Contrast Enhanced Computed Tomography.
For chronic pancreatitis there is TIGARO classification where T stands for Toxins, I stands for Idiopathic, G stands for Genetic, A stands for Autoimmune, R stands for Recurrent, O stands for Obstructive.
Investigation of choice is MRCP.