Pancreatitis, Acute

Pancreatitis, Acute

 

Acute pancreatitis is a reversible inflammatory process of the pancreas.

Epidemiology

  • Incidence  – >200,000 patients per year admitted to the hospital for acute pancreatitis in the U.S.
  • Age – peak age 40-50 years
  • Gender
    • Gallstone-induced pancreatitis, F>M
    • Alcohol-induced pancreatitis, M>F

Risk factors

  • Gallstones/choledocholithiasis
  • Chronic alcohol consumption
  • Drug-induced – estrogen, corticosteroids, isoniazid, metronidazole, azathioprine  
  • Iatrogenic – surgery, post endoscopic retrograde cholangiopancreatography (ERCP)
  • Infection – viral, bacterial, fungal
  • Hyperlipidemia
  • Hypercalcemia, hyperparathyroidism
  • Autoimmune – systemic lupus erythematous
  • Genetic – cystic fibrosis
  • Congenital anomalies – pancreas divisum
  • Tumor
  • Idiopathic

Pathophysiology

  • Inappropriate or premature activation of trypsin thought to be initiating event
  • Early stages are characterized by interstitial edema of pancreatic parenchyma and necrosis of peripancreatic fat
  • In 20% of patients, pancreatitis progresses to coagulation necrosis of glandular elements

Clinical presentation

  • Upper abdominal pain – may radiate to flank, lower abdomen
  • Nausea, emesis
  • Fever, respiratory distress, hypotension
  • Retroperitoneal hemorrhage
    • Grey Turner sign – grey discoloration over flank
    • Cullen sign – bruising in and around umbilicus

Diagnosis

  • Laboratory tests
    • Amylase, lipase
  • Imaging
    • Ultrasound (US) Computed Tomography scan (CT), Endoscopic Retrograde Cholangiopancreatogram (ERCP)

Prognostic criteria

  • Ranson, Imrie scoring system, APACHE II scale
Potential Complications of Acute Pancreatitis
  • Pancreatic - acute fluid collection, necrosis, pseudocyst, abscess, ascites
  • Intestinal - paralytic ileus, GI hemorrhage
  • Hepatobiliary - jaundice, obstruction of the common bile duct, portal vein thrombosis
  • Systemic
    • Metabolic
      • Malnutrition
      • Hypocalcemia
      • Hypoglycemia
    • Hematological
      • Disseminated intravascular coagulation
      • Portal vein thrombosis
  • Renal - acute renal failure
  • Cardiovascular - circulatory failure (shock)
  • Respiratory - hypoxic acute respiratory failure
(Used with permission from Sargent, 2006, 1002)
Clinical Criteria Used in Prognostic Scoring Systems for Acute Pancreatitis
APACHE II Scale Equation includes the following factors: age, rectal temperature, mean arterial pressure, heart rate, PaO2, arterial pH, serum potassium, serum sodium, serum creatinine, hematocrit, white blood cell count, Glasgow Coma Scale score, chronic health status

Click here for APACHE II scoring calculator
CT Severity Index CT grade
A is normal pancreas (0 points)
B is edematous pancreas (1 point)
C is B plus mild extrapancreatic changes (2 points)
D is severe extrapancreatic changes plus one fluid collection (3 points)
E is multiple of extensive fluid collections (4 points)
Necrosis score:
None (0 points)
>one third (2 points)
<one third but less than one half (4 points)
>one half (6 points)

Scoring: CT grade + necrosis score
Imrie Scoring System Age >55 years
White blood cell count >15,000/mm3 (15.0 X 109/L)
Blood glucose >180 mg/dL (10 mmol/L) in patients without diabetes
Serum lactate dehydrogenase >600 U/L
Serum AST or ALT >100 U/L
Serum calcium <8 mg/dL
PaO2 <60 mm Hg
Serum albumin <3.2 g/dL (32 g/L)
Serum urea >45 mg/dL (16.0 mmol/L)

Scoring: One point for each criterion met 48 hours after admission
Ranson’s Criteria At admission or diagnosis:
Age >55 years
White blood cell count >16,000/mm3 (16.0 X 109/L)
Blood glucose >200 mg/dL (11.1 mmol/L)
Serum lactate dehydrogenase >350 U/L
AST >250 U/L

During initial 48 hours:
Hematocrit decrease >10%
Blood urea nitrogen increase >5 mg/dL (1.8 mmol/L)
Serum calcium <8 mg/dL (2 mmol/L)
Base deficit >4 mmol/L (4 mEq/L)
Fluid sequestration >6,000 mL
PaO2 <60 mm HG

Scoring: One point for each criterion met

APACHE II = Acute Physiology and Chronic Health Evaluation; PaO2 = partial arterial oxygen tension; CT = computerized tomography; AST = aspartate transaminase; ALT = alanine transaminase
(Used with permission from Carroll, 2007, 1516)

Clinical Outcomes and Predicative Value of Prognostic Scoring Systems for Acute Pancreatitis

Prognostic Scoring System

Associated Outcomes

Positive LR

Negative LR
APACHE II score =8 at 24 hours Need for intensive care unit, severity, secondary pancreatic infection, pancreatic necrosis, mortality, organ failure and longer hospital stay 1.7 to 4.0 0.25
Imrie score =3 Mortality, severity, pancreatic fluid collections 4.6 0.36
Ranson’s criteria score >3 at 48 hours Major complications, severity, organ failure, pancreatic necrosis, mortality, longer hospital stay 2.4 to 2.5 0.47
LR = likelihood ratio; APACHE II = Acute Physiology and Chronic Health Evaluation
(Used with permission from Carroll, 2007, 1517)

Treatment

  • Supportive
  • Remove anatomic causes (e.g., gallstones)
  • Antibiotics in severe pancreatitis

See Also