Acute Pancreatitis (AP)

Definition

Acute, reversible inflammation, edema, and necrosis/hemorrhage
Caused by inciting trigger (e.g. viral illness) leading to pancreatic (acinar) injury and release of digestive enzymes which results in further cell injury and inflammatory response
Commonly associated with other illnesses

Pediatric mild AP:
- AP that is not associated with any organ failure, local or systemic complications
- Usually resolves within the first week after presentation (recovery of normal physiology and function within 6mo)
- The most common form of pediatric AP
Pediatric moderately severe AP:
- AP with either:
  - Development of transient organ failure/dysfunction (lasting <48 hours)
  - Development of local or systemic complications
    - Local complications would include the development of (peri) or pancreatic complications including fluid collections or necrosis
    - Systemic complications would include exacerbation of previously diagnosed co-morbid disease (such as lung disease or kidney disease)
Pediatric severe AP:
- AP with development of organ dysfunction that persists >48 hours
- Persistent organ failure may be single or multiple, and may develop beyond the first 48 hours of presentation

Amylase
- Up to 45% from pancreas, the rest is from the salivary glands
- Increases within hours and remains elevated for 3-5d
- Also increased with:
  - DKA
  - Renal failure
  - Burns
  - Mumps
  - Anorexia
  - Bulimia
Lipase
- More sensitive for pancreas
- Increases within 6 hours of symptoms; serum levels peak at 24 to 30 hours and can remain elevated for more than 1 week (8-14 days)
Increased Transaminases and GGT suggest biliary obstruction
Calcium decreases due to precipitation in Ca soaps

Infections
Trauma
Biliary Disease
- Cholelithiasis
- Choledochal cyst
- Biliary Sludge
Anatomic
- Pancreatic Divisum
- Annular pancreas
Obstruction
- Duodenal Ulcer
- Tumor of the papilla
- Duodenal Crohns
- Tumor/Mass
Medications
- Valproic acid
- L-asparaginase
- Acetaminophen overdose (see toxins below)
- Azathioprine
- Mercaptopurine
- Mesalamine
- Metronidazole
- Tetracyclines
- Cytarabine
- Furosamide
- Steroids
Genetic
- PRSS1 mutations
- CFTR mutations
- SPINK-1 mutations
Metabolic
- Hypercalcemia
- Hypertriglyceridemia
- Malnutrition
Toxins
- Acetaminophen overdose
- Organophosphates
- Alcohol
- Spider bite
- Scorpion sting venom
- Heroin
- Amphetamines
Systemic Illness
- HUS
- SLE
- HSP/IgAV
- Juvenile RA
- IBD
- CF
- Sickle Cell
- Kawasaki
- Shock/hypoperfusion injury

The presence of systemic inflammatory response syndrome (SIRS) carries an increased risk for developing persistent organ dysfunction
SIRS criteria as per the 2002 International Pediatric Sepsis Consensus:
- The presence of minimum 2 of the following 4 criteria (one of which must be abnormal temperature or leukocyte count):
  - Temperature of >38.5°C or <36°C
  - Leukocyte count elevated or depressed for age or >10% immature neutrophils
  - Elevated heart rate >2SDs above normal for age in the absence of external factors such as associated fussiness, crying, or irritability, or unexplained persistent elevation over a 0.5- to 4-h time period
  - Children younger than 1y:
    - Decreased heart rate <10th percentile for age in the absence of external factors such as vagal stimulation or medications, or otherwise unexplained persistent depression over a 0.5-h time period
  - Mean respiratory rate >2 SD above normal for age or requiring mechanical ventilation for an acute process not related to underlying disease or general anesthesia

Adequate fluid resuscitation with crystalloid appears key especially within the first 24 hours
- 1.5 - 2x MIVF preferably LR improves outcomes
Analgesia may include opioid medications when opioid-sparing measures are inadequate
- Parenteral opioids preferred
- Increase sphincter of Oddi pressure (does not change clinical course or outcomes)
Pulmonary, cardiovascular, and renal status should be closely monitored particularly within the first 48 hours
Enteral nutrition should be started as early as tolerated, whether through oral, gastric, or jejunal route
- No evidence that clears or low fat diet improve outcome
Little evidence supports the use of prophylactic antibiotics, antioxidants, probiotics, and protease inhibitors
Esophago-gastroduodenoscopy, endoscopic retrograde cholangiopancreatography, and endoscopic ultrasonography have limited roles in diagnosis and management
- Used in cases of obstruction (e.g. gallstone)
Children should be carefully followed for development of early or late complications and recurrent attacks of AP