Acute Pancreatitis - Gastrointestinal

Snapshot

A 50-year-old man presents to the emergency room with acute onset epigastric pain. His past medical history includes hyperlipidemia, hypertriglyceridemia, diabetes, and alcohol abuse. His last drink was this morning and he drinks 20 beers a day. He denies any fevers or chills but reports nausea and 2 episodes of nonbloody, nonbilious vomiting. Physical exam is notable for tenderness to palpation of the epigastrium. There is no muscle spasm with percussion of the cheeks. Laboratory evaluation shows significantly elevated amylase and lipase. He is started on aggressive fluid resuscitation.

Introduction

Clinical definition
- acute inflammation of pancreas and surrounding tissue, often by autodigestion with pancreatic enzyme leakage
Epidemiology
- risk factors
  - gallstones (more common)
  - heavy alcohol use (more common)
  - electrolyte abnormalities
    - ↑ serum calcium
  - ↑ triglycerides
  - trauma
  - drugs
    - thiazides
    - sulfa drugs
    - NRTIs
    - protease inhibitors
    - statins
    - valproic acid
    - many others
  - viral infections
    - mumps
  - autoimmune disease
  - endoscopic retrograde cholangiopancreatography (ERCP)
  - scorpion sting
Pathogenesis
- inflammation is caused by leakage of pancreatic enzymes into pancreatic tissue
- causes autodigestion of pancreas and surrounding tissue
Prognosis
- Ranson criteria predict mortality

Ranson Criteria
Clinical Signs
On Admission	Within 48 hours
Glucose > 200 mg/dL Age > 55 years LDH > 350 IU/L WBC > 16,000/mL AST > 250 IU/dL	Calcium < 8.0 mg/dL Hematocrit ↓ by >10% PaO2 < 60 mmHg Base deficit > 4 mEq/L BUN ↑ by 5 mg/dL Sequestered fluid > 6 L
Mortality
3-4 signs	20% mortality
5-6 signs	40% mortality
7+ signs	100% mortality

Presentation

Symptoms
- sudden onset epigastric pain radiating to the back
- nausea and vomiting
- systemic inflammation
  - fever
  - chills
Physical exam
- inspection
  - flank ecchymosis
    - Grey Turner sign
  - periumbilical ecchymosis
    - Cullen sign
      - seen in
        
        acute pancreatitis
        
        hemorrhagic pancreatitis
        
        hemorrhage
- palpation
  - epigastric tenderness

Studies

Diagnostic testing
- imaging
  - abdominal radiograph
    - findings
      - sentinel loop
        
        isolated and dilated loop of bowel seen in inflammatory conditions
  - abdominal ultrasound
    - indication
      - all patients
      - to assess for gallstones
    - findings
      - enlarged pancreas
      - abscess
      - gallstones
  - computed tomography (CT) of abdomen and pelvis with contrast
    - indications
      - diagnosis uncertain
      - failure to improve clinically
      - presence of Grey Turner or Cullen sign, as this may indicate hemorrhagic pancreatitis
    - findings
      - enlarged pancreas
      - indistinct margins (due to inflammation)
      - necrosis
      - peripancreatic fluid
      - pseudocyst
      - abscess
  - CT-guided fine-needle aspiration
    - indications
      - infected necrosis
      - for Gram stain and culture to guide antibiotic selection
- studies
  - ↑ amylase
  - ↑ lipase
  - ↓ calcium
Diagnostic criteria
- diagnosis by 2 or more of the following
  - acute-onset epigastric pain
  - ↑ serum amylase or lipase to 3x upper limit of normal
  - imaging suggestive of pancreatitis

Differential

Peptic ulcer disease
- distinguishing factor
  - also presents with epigastric pain but will not have elevations in pancreatic enzymes

Treatment

Management approach
- remove all offending agents when possible
- treatment will be guided by etiology of pancreatitis
First-line
- supportive care
  - fluid resuscitation
  - electrolyte repletion
  - analgesia
  - bowel rest but feed as soon as tolerated
  - nasogastric decompression
- intravenous antibiotics
Other treatments
- endoscopic retrograde cholangiopancreatography (ERCP) with eventual cholecystectomy
  - indication
    - gallstone pancreatitis
- surgical debridement
  - indication
    - symptomatic necrotizing pancreatitis

Complications

Pancreatic pseudocyst
Fistula formation
Pancreatic abscess
Hemorrhagic pancreatitis
Pleural effusions (often on the left)
Chronic pancreatitis
Disseminated intravascular coagulation (DIC)

Blood, Plasma, Serum	Reference Range
ALT	8-20 U/L
Amylase, serum	25-125 U/L
AST	8-20 U/L
Bilirubin, serum (adult) Total // Direct	0.1-1.0 mg/dL // 0.0-0.3 mg/dL
Calcium, serum (Ca²⁺)	8.4-10.2 mg/dL
Cholesterol, serum	Rec: < 200 mg/dL
Cortisol, serum	0800 h: 5-23 μg/dL //1600 h: 3-15 μg/dL 2000 h: ≤ 50% of 0800 h
Creatine kinase, serum	Male: 25-90 U/L Female: 10-70 U/L
Creatinine, serum	0.6-1.2 mg/dL
Electrolytes, serum
Sodium (Na⁺)	136-145 mEq/L
Chloride (Cl^-)	95-105 mEq/L
Potassium (K⁺)	3.5-5.0 mEq/L
Bicarbonate (HCO₃^-)	22-28 mEq/L
Magnesium (Mg²⁺)	1.5-2.0 mEq/L
Estriol, total, serum (in pregnancy)
24-28 wks // 32-36 wks	30-170 ng/mL // 60-280 ng/mL
28-32 wk // 36-40 wks	40-220 ng/mL // 80-350 ng/mL
Ferritin, serum	Male: 15-200 ng/mL Female: 12-150 ng/mL
Follicle-stimulating hormone, serum/plasma	Male: 4-25 mIU/mL Female: premenopause: 4-30 mIU/mL midcycle peak: 10-90 mIU/mL postmenopause: 40-250
pH	7.35-7.45
PCO₂	33-45 mmHg
PO₂	75-105 mmHg
Glucose, serum	Fasting: 70-110 mg/dL 2-h postprandial:<120 mg/dL
Growth hormone - arginine stimulation	Fasting: <5 ng/mL Provocative stimuli: > 7ng/mL
Immunoglobulins, serum
IgA	76-390 mg/dL
IgE	0-380 IU/mL
IgG	650-1500 mg/dL
IgM	40-345 mg/dL
Iron	50-170 μg/dL
Lactate dehydrogenase, serum	45-90 U/L
Luteinizing hormone, serum/plasma	Male: 6-23 mIU/mL Female: follicular phase: 5-30 mIU/mL midcycle: 75-150 mIU/mL postmenopause 30-200 mIU/mL
Osmolality, serum	275-295 mOsmol/kd H₂O
Parathyroid hormone, serume, N-terminal	230-630 pg/mL
Phosphatase (alkaline), serum (p-NPP at 30° C)	20-70 U/L
Phosphorus (inorganic), serum	3.0-4.5 mg/dL
Prolactin, serum (hPRL)	< 20 ng/mL
Proteins, serum

Hematologic	Reference Range
Bleeding time	2-7 minutes
Erythrocyte count	Male: 4.3-5.9 million/mm³ Female: 3.5-5.5 million mm³
Erythrocyte sedimentation rate (Westergren)	Male: 0-15 mm/h Female: 0-20 mm/h
Hematocrit	Male: 41%-53% Female: 36%-46%
Hemoglobin A1c	≤ 6 %
Hemoglobin, blood	Male: 13.5-17.5 g/dL Female: 12.0-16.0 g/dL
Hemoglobin, plasma	1-4 mg/dL
Leukocyte count and differential
Leukocyte count	4,500-11,000/mm³
Segmented neutrophils	54%-62%
Bands	3%-5%
Eosinophils	1%-3%
Basophils	0%-0.75%
Lymphocytes	25%-33%
Monocytes	3%-7%
Mean corpuscular hemoglobin	25.4-34.6 pg/cell
Mean corpuscular hemoglobin concentration	31%-36% Hb/cell
Mean corpuscular volume	80-100 μm³
Partial thromboplastin time (activated)	25-40 seconds
Platelet count	150,000-400,000/mm³
Prothrombin time	11-15 seconds
Reticulocyte count	0.5%-1.5% of red cells
Thrombin time	< 2 seconds deviation from control
Volume
Plasma	Male: 25-43 mL/kg Female: 28-45 mL/kg
Red cell	Male: 20-36 mL/kg Female: 19-31 mL/kg

Cerebrospinal Fluid	Reference Range
Cell count	0-5/mm³
Chloride	118-132 mEq/L
Gamma globulin	3%-12% total proteins
Glucose	40-70 mg/dL
Pressure	70-180 mm H₂O
Proteins, total	< 40 mg/dL

Sweat	Reference Range
Chloride	0-35 mmol/L
Urine
Calcium	100-300 mg/24 h
Chloride	Varies with intake
Creatinine clearance	Male: 97-137 mL/min Female: 88-128 mL/min
Estriol, total (in pregnancy)
30 wks	6-18 mg/24 h
35 wks	9-28 mg/24 h
40 wks	13-42 mg/24 h
17-Hydroxycorticosteroids	Male: 3.0-10.0 mg/24 h Female: 2.0-8.0 mg/24 h
17-Ketosteroids, total	Male: 8-20 mg/24 h Female: 6-15 mg/24 h
Osmolality	50-1400 mOsmol/kg H₂O
Oxalate	8-40 μg/mL
Potassium	Varies with diet
Proteins, total	< 150 mg/24 h
Sodium	Varies with diet
Uric acid	Varies with diet
Body Mass Index (BMI)	Adult: 19-25 kg/m²