Acute Pancreatitis

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Acute Pancreatitis: Definition & Etiology - Pancreas Ablaze!

  • Definition: Acute inflammatory process of the pancreas, typically reversible, with variable involvement of regional tissues or remote organ systems.
  • Etiology:
    • Gallstones (most common, ~40-50%)
    • Alcohol (~30-40%)
    • 📌 I GET SMASHED mnemonic:
      • Idiopathic
      • Gallstones
      • Ethanol
      • Trauma
      • Steroids
      • Mumps/Malignancy
      • Autoimmune (e.g., IgG4-related)
      • Scorpion sting
      • Hypercalcemia/Hypertriglyceridemia (Triglycerides > 1000 mg/dL)
      • ERCP
      • Drugs (e.g., azathioprine, valproate, thiazides)

⭐ Gallstones and alcohol together account for approximately 70-80% of acute pancreatitis cases in most populations.

Anatomy of Pancreas, Biliary System, and Duodenumoka

Acute Pancreatitis: Pathophysiology - Enzyme Mayhem

  • Core: Pancreatic autodigestion by prematurely activated enzymes in acinar cells.
  • Initiation & Enzyme Cascade:
    • Critical event: Intra-acinar activation of trypsinogen to trypsin.
    • Trypsin activates other zymogens:
      • Proelastase $\rightarrow$ Elastase (vessel/tissue damage).
      • Prophospholipase A2 $\rightarrow$ Phospholipase A2 (membrane damage).
  • Pathological Consequences:
    • Acinar cell injury and necrosis.
    • Local inflammation and cytokine release (TNF-α, IL-1, IL-6), leading to systemic effects (SIRS).
    • Fat necrosis via saponification: $Ca^{2+} + \text{fatty acids} \rightarrow \text{calcium soaps}$; may cause hypocalcemia.

⭐ The critical initiating event in acute pancreatitis is the intra-acinar activation of trypsinogen to trypsin.

Acute Pancreatitis: Clinical & Diagnosis - Spotting the Flames

  • Symptoms: Acute, severe, persistent epigastric pain radiating to back; relieved by leaning forward. Nausea, vomiting.
  • Signs:
    • Epigastric tenderness, guarding.
    • Severe: Tachycardia, hypotension, jaundice.
    • ⚠️ Cullen's sign (periumbilical ecchymosis), Grey Turner's sign (flank ecchymosis) → retroperitoneal hemorrhage, severe disease, poor prognosis. Cullen's sign in acute pancreatitis
  • Diagnosis (Revised Atlanta Criteria - Need 2 of 3):
    1. Characteristic abdominal pain.
    2. Serum amylase and/or lipase ≥ 3x ULN.
    3. Characteristic imaging findings (CECT, MRI, USG).
  • Labs:
    • Lipase: More sensitive & specific than amylase, remains ↑ longer.
    • CRP: ↑ indicates severity.

    ⭐ Serum lipase is preferred over amylase for diagnosing acute pancreatitis due to its higher specificity and longer duration of elevation.

  • Imaging:
    • USG Abdomen: Initial (to detect gallstones).
    • CECT: Best for diagnosis confirmation (if unclear), assessing severity (e.g., necrosis), and detecting complications (usually 48-72 hours after onset if indicated).

Acute Pancreatitis: Severity & Complications - Gauging the Inferno

  • Revised Atlanta Classification:
    • Mild: No organ failure, no local/systemic complications.
    • Moderately Severe: Transient organ failure (<48h) OR local/systemic complications (no persistent organ failure).
    • Severe: Persistent organ failure (>48h).
  • Severity Scoring:
    • BISAP (Bedside Index of Severity in Acute Pancreatitis): 1 point each for:
      • BUN >25 mg/dL
      • Impaired mental status (GCS <15)
      • SIRS (≥2 criteria)
      • Age >60 years
      • Pleural Effusion
      • Score ≥3 indicates ↑ mortality.
    • Others: Ranson's criteria, APACHE II.
  • Local Complications:
    • Acute Peripancreatic Fluid Collection (APFC)
    • Pancreatic Pseudocyst (>4 wks, encapsulated fluid, defined wall)
    • Acute Necrotic Collection (ANC)
    • Walled-Off Necrosis (WON) (>4 wks, encapsulated necrosis ± debris)
    • Infected necrosis (critical)
    • Pancreatic abscess
  • Systemic Complications:
    • SIRS, ARDS, AKI
    • Cardiovascular collapse/shock, DIC
    • Metabolic: Hypocalcemia (saponification), Hyperglycemia

⭐ Hypocalcemia (serum Ca < 8 mg/dL or ionized Ca < 1.0 mmol/L) indicates severe disease and poor prognosis.

CT scan showing pancreatic pseudocyst

High‑Yield Points - ⚡ Biggest Takeaways

  • Gallstones and alcohol abuse are the leading causes of acute pancreatitis.
  • Characterized by severe epigastric pain, often radiating to the back, with nausea and vomiting.
  • Elevated serum lipase (more specific) and amylase are crucial for diagnosis.
  • Ranson's criteria and APACHE II score are used to assess severity and prognosis.
  • Major complications include pancreatic pseudocyst, necrosis, ARDS, and hypocalcemia (saponification).
  • Sentinel loop on X-ray and Grey Turner's/Cullen's signs indicate severe disease.

Practice Questions: Acute Pancreatitis

Test your understanding with these related questions

A 25-year-old obese woman who denies any history of alcohol abuse presents with severe abdominal pain radiating to the back. Laboratory results indicate an increase in serum amylase and lipase, with a marked decrease in calcium. Which of the following likely has caused this condition?

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Flashcards: Acute Pancreatitis

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_____ invasion is characteristic of pancreatic ductal adenocarcinoma

TAP TO REVEAL ANSWER

_____ invasion is characteristic of pancreatic ductal adenocarcinoma

Perineural

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