Acute Pancreatitis


Background

  • Acute pancreatitis (AP) is a common disease of gastroenterology
    • Characterized by auto-digestion of pancreas via inflammatory processes mediated by pancreatic enzymes
    • Diagnosis generally established by 2 out of 3 criteria
      • Epigastric or upper abdominal area pain that may radiate to the back
      • Serum amylase and/or lipase > 3 times upper limit of normal
      • Characteristic findings from abdominal imaging (i.e. Contrast-Enhanced CT or MRI)
         
  • Two distinct phases of AP have now been identified
    • Early (w/in 1 week): systemic inflammatory response syndrome (SIRS) and/or organ failure
    • Late ( > 1 week): local complications
       
  • The Atlanta revised (2013) criteria classifies three types
    • Mild AP: absence of organ failure, absence of local complications
    • Moderately severe AP: local complications and/or transient organ failure < 48 hrs resolved
    • Severe AP: persistent organ failure > 48 hrs w/o resolution
    • Note: Modified Marshal Score for persistent organ failure requires further validation

Mechanism

  • Damage to pancreatic acinar cell, impairs zymogen granule secretions, early edema to gland leading to activation of pancreatic enzymes and autodigestion
    • Inflammatory processes (i.e. PMNs and macrophages release of proteolytic enzymes, superoxide, cytokines) resulting in pancreatic hemorrhage and necrosis
    • Rarely patients develop Systemic Inflammatory Response Syndrome (SIRS) likely mediated by pancreatic enzymes and cytokines released into systemic circulation from the inflamed pancreas
  • Pseudocyst formation can result from necrotic pancreatic or peripancreatic tissue that has been walled off by granulation tissue or bacterial seeding (abscess)
  • Most AP self-limiting and resolves < 48 hrs w/ only adequate hydration (mild or moderately severe AP)
  • Severe AP persistent organ failure > 48 hrs

Etiology

  • Mechanical obstruction
    • Gallstones (40-70%) most common cause
    • Sludge or other biliary tract disease
    • Cancer, ampullary stenosis, duodenal stricture or obstruction
  • Toxic
    • Ethanol, especially in alcoholism, is second most common cause (25-35%)
    • Methanol poison, scorpion venom, organophosphate poisoning
  • Metabolic
    • Hyperlipidemia
    • Hypercalcemia
  • Drugs
    • Estrogens, thiazide diuretics, furosemide, sulfonamides, tetracycline, steroids, INH, ASA, azathioprine, valproic acid
    • AIDS drugs (didanosine, pentamidine), metronidazole, enalapril, statins, and many others
  • Infection
    • Viruses- mumps, coxsackie, EBV, hepatitis B, CMV, VZV, HSV, HIV
    • Bacteria- mycoplasma, Legionella, Leptospira, salmonella
  • Trauma
    • Blunt or penetrating
    • Iatrogenic injury during surgery or ERCP
  • Congenital
    • Pancreas divisum
  • Vascular
    • Ischemia, atheroembolism, vasculitis
  • Genetic
    • CFTR and others
  • Miscellaneous
    • Pregnancy, post-ERCP
    • Idiopathic (30%)

Clinical Features

  • Mid-epigastric constant, boring pain radiating to back and worse when supine
  • Nausea, vomiting, abdominal distention
  • Fever
  • Tachycardia, hypotension
  • Altered mental status
  • Shock

Diagnosis

  • History/Symptoms
    • Abdominal pain
      • Constant, epigastric, radiates to back
      • At times can be diffuse or RUQ
    • Nausea, vomiting, intractable hiccups, retching
    • Marked distress
      • Inability to find comfortable position, paucity of other findings
    • Diarrhea less common
    • If suspect EtOH: establish abuse and duration
    • Gallstones
       
  • Physical exam/Signs
    • General, Vitals: acute pain and guarding, jaundice if obstruction of common bile duct present, fever
    • Abd/GI/GU
      • Abdominal tenderness
      • Ileus: Abd distention, commonly associated
      • Cullen's sign (Periumbilical bluish discoloration from intraperitoneal hemorrhage)
    • Respiratory
      • Respiratory distress (33%): range from tachypnea to focal atelectasis to uni-/bilateral pleural effusions (left pleural effusion very suggestive)
      • Tachypnea and shallow respirations due to pain
    • Cardiovascular
      • Tachycardia
      • Hypotension (shock w/ severe or hemorrhagic dz)
    • Neurological/Musculoskeletal
      • Chvostek's sign (Tapping the facial nerve near tragus elicits twitching of nose or lips)
    • Extremities/Skin
      • Peripheral signs of fat necrosis
      • Grey-Turner's sign (Flank/ groin discoloration from retroperitoneal hemorrhage)
         
  • Labs/Tests
    • Amylase
      • Hallmark , not specific
      • Levels >1000 IU/dL are usually Gallstone Pancreatitis  as alcoholic pancreatitis rarely reaches these levels
    • Lipase
      • Fewer false positives
      • ≥ 2-3 times normal (Acute)
      • Not w/ parotitis or macroamylasemia
    • CBC, CMP, Ca, glucose, EtOH level
    • Level of pancreatic enzyme elevation does not correlate with severity
       
  • Imaging
    • KUB
      • Signs of gas-filled abscess in region of pancreas, calcifications (chronic), ascites w/ ground glass, sentinel loop ileus (air filled loop of bowel near pancreas), obscured psoas
    • CXR
      • Pleural effusion (left usually), diaphragm elevation (one or both), atelectasis or infiltrate
    • Ultrasound
      • Swelling and edema of pancreas, abscess or cyst, or calcifications; and etiology including biliary disease, gallstones
    • CT w/Contrast
      • Most important imaging test for Dx and assessment of severity
      • CT scan to be used if no improvement w/ initial conservative Tx, if complication suspected, or if other Dx considered
      • Clearer picture of pancreas, definition of pseudocyst formation or ductal calcification
    • MRI
      • Better categorizes fluid collections (acute, necrotic, hemorrhage, abscess, pseudocyst)
      • Greater sensitivity than CT to Dx mild cases
         
  • Other Tests/Criteria
    • 2013 American College of Gastroenterology guidelines for severity assessment should be used:
      • Patient Characteristics
        • > 55 yo
        • Obese (BMI > 30 kg/m2)
        • Alter mental status
        • Comorbid dz
      • SIRS score (≥ 2)
        • Temp > 38 C or < 36 C
        • HR > 90 bpm
        • RR > 20 or PaCO2 < 32 mmHg
        • WBC > 12,000 or < 4,000 or > 10% bands
      • Lab Findings
        • BUN > 20 mg/dl and rising
        • HCT > 44% and rising
        • Elevated creatinine
      • Radiological Findings
        • Pleural effusions
        • Pulmonary infiltrates
        • Multiple or extensive extrapancreatic collections

 

  • Lipase ≥ 2-3 times normal (Acute), Amylase is non-specific.
  • Elevated Alkaline Phosphatase level suggest biliary disease & gallstone Pancreatitis.
  • Imaging findings consistent with diagnosis
    • Evaluate for gallstone pancreatitis
    • CT w/ contrast is imaging study of choice.

Ranson's Criteria

Greater than 3 positives indicate severe disease

  • On admission
    • Age > 55 yo
    • WBC > 16,000
    • Glucose > 200 mg/dL
    • LDH > 350 IU
    • AST > 250
       
  • At 48 hrs
    • Hct decr 10%,
    • BUN incr 5 mg/dL [1.8 mmol/L]
    • Ca < 8 mg/dL [< 2 mmol/L]
    • PO2 < 60 mmHg, base excess decr > 4 mEq/L
    • Estimated retroperitoneal fluid sequestration > 6 L
       
  • Mortality
    • < 3 signs 0-3%
    • 3-4 signs 11-15%
    • 5-6 signs 40%
    • ≥ 7 signs 100%

Treatment

  1. Initial/Prep
    • ABCs, pain management, IV fluid hydration (aggressive)
    • Aggressive IV fluid hydration
      • 250-500 ml/hr Lactated Ringer's solution recommended
      • Most beneficial in first 12-24 hrs
      • If severe volume depletion (hypotension, tachycardia), more rapid repletion (physician discretion) may be required
      • Assess frequently within 6 hrs of admission (goal to decrease BUN)
    • NPO
      • NG tube ONLY if pt is vomiting
         
  2. Antiemetics
    • Zofran 4mg IV q4-6h prn
    • Promethazine 25mg IM q4h prn
       
  3. Pain control:
    • Morphine Sulfate 1-5mg IV q4h prn
    • Dilaudid 2mg IV q2h prn
    • Ketorolac 30mg IV initially, followed by 15mg q8h for 3 days.
       
  4. Antibiotics in patients with infected pseudocyst, abscess or peripancreatic fluid
    • Primaxinc (Imipenem-cilastatin ) 500-1000 mg IV q6h -OR-
    • Meropenem 1 g IV -OR-
    • Ciprofloxacin 400 mg IV q12h + Metronidazole 500 mg IV -OR-
    • Ceftriaxone 1-2g IV q2h -OR-
    • Ampicillin 500 mg IV q6h
       
  5. Symptomatic hypocalcemia should be corrected
    • Calcium replacement: Ca-Gluconate 500-1000 mg PO qid
       
  6. Magnesium replacement
    • Mg-Sulfate 1-2g IV q6h on first day, then 60mg/kg/day as infusion.
       
  7. Insulin
    • MDSSI
       
  8. ERCP for patients with gallstone pancreatitis
  9. Pseudocyst on CT --> percutaneous aspiration (IR vs Surgery consult)
  10. Pt with severe systemic disease will require:
    • Intubation
    • Intensive monitoring
    • Bladder Cath, &
    • Transfusion of blood & blood products as needed.
       
  11. Symptomatic hypocalcaemia should be corrected.
  12. Laparotomy may be indicated for hemorrhage or abscess drainage.

Disposition

  1. Admit prereqs
    • All pts with symptomatic AP
    • Most pts will require hospitalization.
      • Pt who demonstrate poor prognostic signs (dropping Hb, poor urine output, persistent hypotension, hypoxia, acidosis, or hypocalcaemia) despite aggressive early treatment should be admitted to ICU with surgical consult.
         
  2. Consults
    • Gastroenterology, ICU, Infectious Disease if necessary, Nutritionist, Surgery
  3. Follow-up if applicable
    • Follow-up with primary care or surgical dept
  4. Discharge:
    • Patients with mild, uncomplicated pancreatitis and no biliary tract disease may be discharged with close follow-up if they are PO tolerant.
    • Pts with mild disease, no biliary tract, & no evidence of systemic complication may be managed as outpatients with close follow-up if they tolerate liquids and oral analgesics in ED.
    • Instruct pt to increase their diet as tolerated once nausea is controlled.

     

 

Admission Orders: Acute Pancreatitis

1. Admit to:

2. Diagnosis: Acute pancreatitis

3. Condition:

4. Vital Signs: q1-4h, call physician if BP >160/90, <90/60; P >120, <50; R>25, <10; T >38.5°C; urine output < 25 cc/hr for more than 4 hours.

5. Activity: Bed rest with bedside commode.

6. Nursing: Inputs and outputs, fingerstick glucose qid, guaiac stools. Foley to closed drainage.

7. Diet: NPO

8. IV Fluids: 1-4 L NS over 1-3h, then D5 ½ NS with 20 mEq KCL/L at 125 cc/hr.

9. Special Medications:



? Pseudocyst:

- Imipenem/Cilastone (Primaxin) 0.5-1.0 g IV q6h.
OR
Ampicillin/sulbactam (Unasyn) 3.0 gm IV q6h
OR
Rocephin 1-2 g IV q12h
OR
Cipro 400 mg IV q12h

 

- Heparin 5000 U SQ q12h.

-Total parenteral nutrition.

10. Symptomatic Medications:

-Morphine sulfate 2-4 mg IV q2-6h prn pain.
OR
- Ketorolac 30 mg IV initially, followed by 15 mg IV q8h x 3 days
-
Ranitidine (Zantac) 50 mg IV q6-8h OR- Famotidine (Pepcid) 20 mg IV q12h.
- Zofran 4 mg IV q4-6h prn n/v


 

11. Extras: 
   Upright abdomen x-ray, portable CXR, ECG, ultrasound, CT with contrast. Surgery and GI consults.


12. Labs:
 
   CBC, CMP, Calcium, Lipid Panel, Amylase, Lipase; blood C&S x 2, INR/PTT, type and hold 4-6 U PRBC and 2-4 U FFP. UA w/ C&S,