Acute Pancreatitis

Quick Answer

Acute pancreatitis is an inflammatory condition of the pancreas diagnosed by 2 of 3 criteria: characteristic abdominal pain, serum lipase (or amylase) greater than 3× upper limit of normal, and characteristic imaging findings. Severity ranges from mild self-limiting (85%) to severe with persistent organ failure (15-20% with 15-20% mortality). Management centers on aggressive early fluid resuscitation (5-10 mL/kg/h crystalloid, preferably Ringer's lactate), early enteral nutrition (within 24-48h), treating underlying cause (gallstones, alcohol), and managing complications (necrosis, infection, organ failure). ERCP is indicated only for cholangitis or persistent biliary obstruction, NOT routine acute pancreatitis.

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CICM Exam Focus

Must-Know for Written Exam

1. Diagnostic criteria: 2 of 3 (pain, lipase greater than 3× ULN, imaging)
2. Revised Atlanta Classification: Mild, moderately severe, severe
3. Severity scoring: APACHE-II, Ranson, BISAP, modified Marshall
4. Fluid resuscitation: 5-10 mL/kg/h crystalloid, goal-directed (RL > NS)
5. Early enteral nutrition: Within 24-48h, superior to TPN
6. Complications: ARDS, AKI, pancreatic necrosis (30%), infected necrosis
7. ERCP indications: Cholangitis, persistent biliary obstruction (NOT routine)
8. Antibiotic use: Only for infected necrosis (proven), NOT prophylactic
9. Intra-abdominal hypertension: Monitor bladder pressure, ACS threshold greater than 20 mmHg
10. Aetiology: Gallstones (40%), alcohol (30%), hypertriglyceridemia, drugs, ERCP

Viva Scenarios

Scenario 1: 58-year-old with severe gallstone pancreatitis, ARDS, requiring mechanical ventilation Scenario 2: 42-year-old alcoholic with necrotizing pancreatitis, intra-abdominal hypertension Scenario 3: Young patient with hypertriglyceridemia-induced pancreatitis Scenario 4: Infected pancreatic necrosis, septic shock, need for intervention

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Key Points

• Acute pancreatitis affects 13-45 per 100,000 population annually, increasing incidence
• 85% mild disease (interstitial edematous), 15% severe (necrosis, organ failure)
• Diagnosis requires 2 of 3: abdominal pain, lipase greater than 3× ULN, characteristic imaging
• Revised Atlanta Classification (2012): Mild (no organ failure), Moderately Severe (transient organ failure below 48h or local complications), Severe (persistent organ failure greater than 48h)
• Aggressive early fluid resuscitation (5-10 mL/kg/h) in first 12-24h reduces mortality
• Ringer's lactate preferred over normal saline (reduces SIRS, mortality)
• Early enteral nutrition (within 24-48h) reduces mortality, infection, organ failure vs TPN
• Pancreatic necrosis develops in 20-30% of severe cases, usually after 4-7 days
• Infected necrosis occurs in 30-40% of necrosis cases, usually after 2nd week
• ERCP indicated for cholangitis or persistent biliary obstruction, NOT routine acute pancreatitis
• Prophylactic antibiotics NOT recommended (no mortality benefit, increases resistance)
• Antibiotics for infected necrosis: Carbapenems (imipenem, meropenem) or fluoroquinolones + metronidazole
• Mortality: Mild 1-2%, Moderately Severe 5-10%, Severe 15-20%

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Clinical Overview

Definition

Acute pancreatitis is an acute inflammatory process of the pancreas with variable involvement of peripancreatic tissues and remote organ systems. The pathological hallmark is autodigestion of pancreatic tissue by prematurely activated digestive enzymes (particularly trypsin).

Pathophysiology

Enzyme Activation Cascade

1. Triggering event (e.g., gallstone obstruction, alcohol) → acinar cell injury
2. Premature intracellular activation of digestive enzymes (trypsinogen → trypsin)
3. Trypsin activates other proenzymes (phospholipase A2, elastase, chymotrypsin)
4. Autodigestion of pancreatic parenchyma, blood vessels, surrounding tissues
5. Local inflammatory response: Cytokine release (TNF-α, IL-1, IL-6, IL-8)
6. Systemic inflammatory response syndrome (SIRS) in severe cases
7. Microvascular injury → capillary leak, third-space fluid losses
8. Organ dysfunction: ARDS, AKI, cardiovascular collapse

Necrosis Development

• Pancreatic necrosis: Develops 20-30% of severe cases, usually 4-7 days
• Ischaemia: Microvascular thrombosis, hypoperfusion
• Cell death: Coagulative necrosis of pancreatic and peripancreatic tissue
• Infection risk: Necrotic tissue prone to bacterial translocation from gut (usually after week 2)

Fluid Sequestration

• Third-space losses: Up to 6-10 liters in first 24-48h
• Mechanisms: Increased capillary permeability, ascites, retroperitoneal fluid
• Hypovolemia: Decreased effective circulating volume
• Organ hypoperfusion: AKI, shock, ARDS

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Epidemiology

Incidence and Prevalence

• Global incidence: 13-45 per 100,000 population annually [PMID: 23896955]
• Increasing trend: 20-30% increase over past 2 decades
• Age distribution: Bimodal (gallstone disease in elderly, alcohol in younger)
• Sex ratio: Gallstone pancreatitis more common in females (3:1), alcohol in males (6:1)

Australia and New Zealand Context

• Australia: ~30-40 per 100,000 population annually
• New Zealand: Similar rates, higher Māori incidence (gallstone disease prevalence)
• ICU admissions: ~15-20% of acute pancreatitis cases require ICU
• Mortality: Overall 5-10%, severe pancreatitis 15-20%

Aetiology

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Diagnosis

Revised Atlanta Classification (2012)

Diagnostic criteria (require 2 of 3) [PMID: 23384656]:

1. Abdominal pain consistent with acute pancreatitis (epigastric, radiating to back)
2. Serum lipase (or amylase) greater than 3× upper limit of normal
3. Characteristic imaging findings on CT, MRI, or ultrasound

Clinical Presentation

Symptoms

• Epigastric pain (90-95%): Severe, constant, radiating to back
• Nausea and vomiting (70-90%)
• Abdominal distension (50-70%)
• Fever (40-60%)

Signs

• Epigastric tenderness (90%)
• Abdominal guarding (30-50%)
• Decreased bowel sounds (ileus)
• Jaundice (20-30%, especially gallstone aetiology)
• Grey-Turner sign (flank ecchymosis, below 1%, late sign of retroperitoneal hemorrhage)
• Cullen sign (periumbilical ecchymosis, below 1%, late sign)

Investigations

Serum Biochemistry

Pancreatic enzymes:

• Lipase: More sensitive and specific than amylase (94% vs 86% sensitivity) [PMID: 19736354]
  • "Peak: 24-48 hours"
  • "Duration: Remains elevated 7-14 days (longer than amylase)"
  • "Threshold: greater than 3× ULN for diagnosis"
• Amylase: Less specific (elevated in other conditions)
  • "Peak: 2-12 hours"
  • "Duration: Returns to normal 3-5 days"
  • "False positives: Perforated viscus, bowel ischaemia, salivary disease"

Severity markers:

• Haematocrit: greater than 44% on admission predicts necrosis [PMID: 10749955]
  • Rising Hct in first 24h predicts severe disease
• Creatinine: Elevated BUN greater than 25 mg/dL or Cr rise predicts severity
• Lactate: greater than 2 mmol/L predicts organ failure
• CRP: greater than 150 mg/L at 48h predicts necrosis (sensitivity 80%, specificity 76%) [PMID: 16964738]

Aetiology investigations:

• Liver function tests: ALT greater than 150 IU/L suggests gallstone aetiology (95% PPV) [PMID: 8333794]
• Triglycerides: Check if lactescent serum, greater than 11.3 mmol/L diagnostic
• Calcium: Hypercalcemia (hyperparathyroidism)
• Glucose: Hyperglycemia (pancreatic endocrine dysfunction)

Imaging

Ultrasound (first-line):

• Indications: All patients to assess for gallstones, biliary dilatation
• Findings: Gallstones (sensitivity 95%), CBD dilatation, pancreatic enlargement
• Limitations: Pancreas often obscured by bowel gas

Contrast-enhanced CT (CECT):

• Timing: NOT in first 48-72h (necrosis not yet evident) [PMID: 23979992]
  • Perform if diagnosis uncertain, no clinical improvement by 48-72h, or clinical deterioration
• CT Severity Index (CTSI): Balthazar score + necrosis extent
  • "Grade A: Normal pancreas (0 points)"
  • "Grade B: Focal or diffuse enlargement (1 point)"
  • "Grade C: Peripancreatic inflammation (2 points)"
  • "Grade D: Single peripancreatic collection (3 points)"
  • "Grade E: Two or more collections or gas (4 points)"
  • "Necrosis: None (0), below 30% (2), 30-50% (4), greater than 50% (6)"
  • CTSI = Balthazar + Necrosis (0-10 scale)
  • "CTSI 7-10: Mortality 17%, morbidity 92% [PMID: 2188967]"

MRI/MRCP:

• Indications: Contraindication to CT contrast, better soft tissue characterization
• Advantages: Superior for detecting biliary stones, pancreatic duct anatomy

Severity Scoring Systems

APACHE-II Score (most validated):

• Performed: On admission and daily in first 48h
• Threshold: ≥8 predicts severe pancreatitis (sensitivity 75%, specificity 82%) [PMID: 23979992]
• Advantages: Continuous assessment, widely used in ICU
• Disadvantages: Complex calculation

Ranson Criteria (traditional):

• On admission (0-24h): Age greater than 55y, WCC greater than 16×10⁹/L, glucose greater than 11 mmol/L, LDH greater than 350 IU/L, AST greater than 250 IU/L
• After 48h: Hct drop greater than 10%, BUN rise greater than 1.8 mmol/L, Ca²⁺ below 2 mmol/L, PaO₂ below 60 mmHg, Base deficit greater than 4, Fluid sequestration greater than 6L
• Interpretation: ≥3 criteria = severe disease (mortality 15%), ≥6 criteria (mortality 40%)
• Disadvantages: Requires 48h, cannot be repeated

BISAP Score (simple, 0-5):

• BUN greater than 25 mg/dL (greater than 8.9 mmol/L)
• Impaired mental status (GCS below 15)
• SIRS (≥2 criteria)
• Age greater than 60 years
• Pleural effusion on imaging
• Interpretation: ≥3 predicts mortality 5-8%, organ failure [PMID: 18997220]
• Advantages: Simple, calculated within 24h

Modified Marshall Score (organ failure):

• Respiratory: PaO₂/FiO₂ ratio (below 400, below 300, below 200)
• Renal: Creatinine (μmol/L) (134-169, 170-310, greater than 310)
• Cardiovascular: Systolic BP (mmHg) (below 90, below 90 fluid unresponsive, below 90 pH below 7.3)
• Organ failure: Score ≥2 in any system
• Persistent organ failure: greater than 48h duration (defines severe pancreatitis)

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Severity Classification

Revised Atlanta Classification (2012) [PMID: 23384656]

Organ failure definitions (Modified Marshall Score ≥2):

• Respiratory: PaO₂/FiO₂ ≤300
• Renal: Creatinine ≥170 μmol/L (≥1.9 mg/dL)
• Cardiovascular: SBP below 90 mmHg despite fluid resuscitation

Local complications:

• Acute peripancreatic fluid collection (APFC): below 4 weeks, no wall
• Pancreatic pseudocyst: greater than 4 weeks, well-defined wall, no solid component
• Acute necrotic collection (ANC): below 4 weeks, necrosis + fluid
• Walled-off necrosis (WON): greater than 4 weeks, mature wall encasing necrosis

Systemic complications:

• Exacerbation of pre-existing comorbidity (cardiac, respiratory, renal)

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Management

ICU Admission Criteria

Indications for ICU admission [PMID: 23979992]:

• Persistent organ failure (cardiovascular, respiratory, renal)
• APACHE-II ≥8, Ranson ≥3, BISAP ≥3
• Intra-abdominal hypertension (IAP greater than 12 mmHg) or ACS (IAP greater than 20 mmHg)
• Hemodynamic instability requiring vasopressors
• Acute respiratory failure requiring mechanical ventilation
• Severe metabolic derangement (lactate greater than 4, severe acidosis)

Fluid Resuscitation

Goal-directed fluid therapy is the cornerstone of early management [PMID: 20551112]:

Initial resuscitation (first 12-24h):

• Rate: 5-10 mL/kg/h crystalloid (aggressive early resuscitation)
• Fluid choice: Ringer's lactate preferred over normal saline
  • "PMID: 21494491: RL reduced SIRS (69% vs 87%, p=0.03) and CRP at 24h (median 68 vs 123 mg/L)"
  • Lactate buffering may reduce systemic inflammation
• Route: Intravenous (preferably large-bore peripheral or central access)

Goals (first 24h):

• Urine output: greater than 0.5 mL/kg/h (aim 0.5-1 mL/kg/h)
• Mean arterial pressure: greater than 65 mmHg
• Heart rate: below 120 bpm
• Haematocrit: Target 35-44% (rising Hct predicts inadequate resuscitation)

Reassessment (after 24h):

• Transition to moderate resuscitation (3-5 mL/kg/h) once goals achieved
• Avoid fluid overload: Positive fluid balance greater than 4L at 24h associated with worse outcomes [PMID: 24572622]
• Monitor: Clinical exam, urine output, lactate, Hct, BUN

Caveats:

• Avoid under-resuscitation: Increases pancreatic necrosis, organ failure
• Avoid over-resuscitation: Abdominal compartment syndrome, pulmonary oedema
• Goal-directed approach: Individualized based on response

Nutritional Support

Early enteral nutrition (EN) is superior to total parenteral nutrition (TPN) [PMID: 20551112]:

Timing:

• Start within 24-48h of admission (as tolerated)
• Oral diet: If mild pancreatitis, no ileus, tolerating oral intake
• Enteral tube feeding: If severe pancreatitis, prolonged NPO expected

Route:

• Nasogastric (NG) tube: Equally effective as nasojejunal (NJ) [PMID: 24860368]
  • NG simpler, less expensive, fewer complications
  • Use unless post-pyloric required (high gastric residuals, intolerance)
• Nasojejunal (NJ) tube: If NG intolerance, severe ileus

Formulation:

• Polymeric standard formula: First-line
• Semi-elemental/elemental: If malabsorption, intolerance
• Low-fat: Traditional recommendation, but evidence limited

Evidence:

• Reduced mortality: EN vs TPN (RR 0.50, 95% CI 0.28-0.91) [PMID: 20551112]
• Reduced infection: EN vs TPN (RR 0.45, 95% CI 0.26-0.78)
• Reduced organ failure: EN vs TPN (RR 0.54, 95% CI 0.31-0.94)
• Mechanism: Maintains gut barrier, reduces bacterial translocation

TPN indications (if EN not possible):

• Ileus greater than 5-7 days
• Abdominal compartment syndrome
• High-output fistula
• EN intolerance despite NJ feeding

Probiotics: NOT recommended (PROPATRIA trial increased mortality) [PMID: 18283134]

Pain Management

Analgesia options:

• Opioids: Morphine, fentanyl, hydromorphone
  • "Morphine: Historical concern about sphincter of Oddi spasm (minimal clinical significance)"
  • "Fentanyl: Preferred by some (less sphincter effect)"
• Patient-controlled analgesia (PCA): Effective for severe pain
• Epidural analgesia: May reduce systemic inflammation, SIRS (limited evidence) [PMID: 23979992]
• NSAIDs: Avoid (risk of AKI, bleeding)

Treatment of Underlying Cause

Gallstone pancreatitis:

• ERCP indications [PMID: 23979992]:
  • "Cholangitis (Charcot's triad: fever, jaundice, RUQ pain) – perform within 24h"
  • Persistent biliary obstruction (progressive jaundice, persistent CBD dilatation)
  • NOT for predicted severe pancreatitis alone (no mortality benefit, increases complications)
• Cholecystectomy timing:
  • "Mild pancreatitis: Same admission (within 2 weeks), ideally once symptoms resolved"
  • "Severe pancreatitis: Delayed 6-8 weeks (after acute inflammation resolved)"
  • "PMID: 21865463: Early cholecystectomy reduced recurrent pancreatitis (0% vs 17%)"

Alcohol-induced pancreatitis:

• Abstinence counseling: Essential to prevent recurrence
• Thiamine: 100mg IV/PO daily (prevent Wernicke's)
• Withdrawal prophylaxis: Benzodiazepines if at risk

Hypertriglyceridemia-induced pancreatitis:

• Insulin + dextrose: Activates lipoprotein lipase, lowers TG rapidly
  • Insulin 0.1-0.3 units/kg/h + dextrose 5-10% infusion (maintain glucose 8-12 mmol/L)
  • "Target: TG below 5.6 mmol/L (below 500 mg/dL)"
• Plasmapheresis: If TG greater than 22.6 mmol/L (greater than 2,000 mg/dL) or refractory [PMID: 26743476]
• Fibrates: Start after acute phase (gemfibrozil, fenofibrate)

Drug-induced pancreatitis:

• Stop offending agent: Azathioprine, 6-MP, valproate, mesalazine, etc.

Antibiotic Therapy

Prophylactic antibiotics: NOT recommended [PMID: 23979992]

• Multiple RCTs show no mortality benefit
• Increases antibiotic resistance, fungal infections
• Prior era of prophylaxis (imipenem) based on flawed studies

Antibiotics for infected necrosis (proven or suspected):

• Indications:
  • Gas in necrotic collection on CT (pathognomonic)
  • Persistent sepsis despite source control (positive blood cultures)
  • FNA of necrosis with positive Gram stain/culture
• Choice: Pancreatic penetration essential
  • "Carbapenems: Imipenem 500mg IV q6h, Meropenem 1g IV q8h (best penetration)"
  • "Fluoroquinolones + Metronidazole: Ciprofloxacin 400mg IV q12h + Metronidazole 500mg IV q8h"
  • "Duration: Until source controlled, clinical improvement (usually 2-3 weeks)"
• Fungal coverage: Consider if prolonged antibiotics, high risk (fluconazole, echinocandins)

Management of Complications

Acute Respiratory Distress Syndrome (ARDS)

Incidence: 15-20% of severe pancreatitis [PMID: 8263428]

Pathophysiology:

• Systemic inflammation (TNF-α, IL-1, IL-6) → capillary leak
• Phospholipase A2 → surfactant destruction
• Diaphragmatic splinting (abdominal distension)

Management [PMID: 10872010]:

• Lung-protective ventilation: Tidal volume 6 mL/kg ideal body weight
• PEEP: 5-15 cmH₂O (titrated to oxygenation, compliance)
• Plateau pressure: below 30 cmH₂O
• Permissive hypercapnia: pH greater than 7.20
• Prone positioning: If PaO₂/FiO₂ below 150 mmHg despite optimal PEEP
• Neuromuscular blockade: If PaO₂/FiO₂ below 150 mmHg (first 48h)
• Conservative fluid strategy: After resuscitation phase (avoid fluid overload)

Acute Kidney Injury (AKI)

Incidence: 20-30% of severe pancreatitis [PMID: 23979992]

Causes:

• Hypovolemia (third-space losses)
• Abdominal compartment syndrome
• Contrast nephropathy
• Direct inflammatory injury

Management:

• Optimize hemodynamics: Fluid resuscitation, MAP greater than 65 mmHg
• Avoid nephrotoxins: NSAIDs, aminoglycosides
• Monitor: Urine output, creatinine, fluid balance
• Renal replacement therapy (RRT): If severe (AKIN stage 3, refractory acidosis/hyperkalemia, volume overload)
  • CVVHDF preferred over IHD (hemodynamic stability)

Intra-Abdominal Hypertension (IAH) / Abdominal Compartment Syndrome (ACS)

Definitions [PMID: 23979992]:

• IAH: Intra-abdominal pressure (IAP) ≥12 mmHg
• ACS: IAP greater than 20 mmHg + new organ failure

Incidence: 30-60% of severe pancreatitis develop IAH, 10-15% develop ACS

Measurement:

• Bladder pressure: Gold standard (via Foley catheter, 25 mL saline instillation)
• Frequency: Every 4-6h if at risk

Management:

• IAP 12-20 mmHg: Medical management
  • NG decompression, prokinetics (metoclopramide, erythromycin)
  • Avoid excessive fluid overload
  • Analgesia, sedation (reduce abdominal wall tone)
• IAP greater than 20 mmHg with organ failure: Consider decompressive laparotomy
  • High morbidity (40-60% mortality), last resort
  • "Alternatives: Percutaneous drainage of collections"

Pancreatic Necrosis

Sterile necrosis:

• Management: Conservative (supportive care, EN, monitoring)
• Surgery NOT indicated: No mortality benefit, increases complications
• PANTER trial [PMID: 20484315]: Early surgery vs conservative management
  • Mortality 19% vs 16% (NS)
  • Major complications 69% vs 40% (pbelow 0.001)

Infected necrosis:

• Incidence: 30-40% of necrotic pancreatitis (usually after 2nd week)
• Diagnosis: Gas in necrosis on CT, FNA with positive culture
• Management: Step-up approach [PMID: 20484316]
  1. Antibiotics: Carbapenems or fluoroquinolones + metronidazole
  2. Percutaneous drainage: If no improvement 48-72h
  3. Minimally invasive necrosectomy: If drainage fails (video-assisted, endoscopic)
  4. Open necrosectomy: Last resort (high morbidity)
• PANTER trial: Step-up approach reduced major complications (40% vs 69%, pbelow 0.001) vs open necrosectomy
• Timing: Delay intervention ≥4 weeks if possible (allows demarcation, walled-off necrosis easier to drain)

Special Considerations

Pregnant Patients

• Second trimester gallstone pancreatitis: Most common
• Fluid resuscitation: Judicious (avoid pulmonary oedema)
• ERCP: Safe with abdominal shielding
• Delivery: If maternal or fetal distress

Chronic Pancreatitis Patients

• Acute-on-chronic exacerbation: Manage as acute pancreatitis
• Consider: Pancreatic duct obstruction (stricture, stone, tumour)
• ERCP/MRCP: May be diagnostic and therapeutic

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Prognosis

Mortality

Predictors of mortality [PMID: 23979992]:

• Persistent organ failure (cardiovascular, respiratory, renal) greater than 48h
• Age greater than 70 years
• Obesity (BMI greater than 30)
• Elevated APACHE-II (≥8), Ranson (≥3), BISAP (≥3)
• Pancreatic necrosis greater than 30%
• Infected necrosis

Long-Term Outcomes

Recurrence risk:

• Gallstone pancreatitis without cholecystectomy: 30-50% recurrence within 6 months [PMID: 21865463]
• Alcohol-induced without abstinence: 50-70% recurrence
• After cholecystectomy: below 5% recurrence (usually other causes)

Chronic pancreatitis development:

• Alcohol-induced: 10-15% progress to chronic (higher if continued drinking)
• Other causes: below 5% progression

Diabetes mellitus:

• Severe pancreatitis: 15-20% develop DM long-term (pancreatic endocrine insufficiency)
• Pancreatic resection: 30-50% develop DM

Exocrine insufficiency:

• Severe pancreatitis with extensive necrosis: 20-30% develop exocrine insufficiency
• Symptoms: Steatorrhea, weight loss, fat-soluble vitamin deficiency
• Treatment: Pancreatic enzyme replacement (Creon)

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Evidence Summary

Key Trials and Guidelines

1. IAP/APA Guidelines (2013) [PMID: 23979992]

   • Comprehensive evidence-based recommendations for acute pancreatitis management
   • 42 recommendations across diagnosis, aetiology, severity, fluid, nutrition, ERCP, antibiotics

2. Ringer's Lactate vs Normal Saline [PMID: 21494491]

   • Single-center RCT, 40 patients
   • RL reduced SIRS (69% vs 87%, p=0.03) and CRP at 24h (68 vs 123 mg/L, p=0.02)

3. Early EN vs TPN [PMID: 20551112]

   • Meta-analysis of 8 RCTs, 348 patients
   • EN reduced mortality (RR 0.50, 95% CI 0.28-0.91), infection (RR 0.45), organ failure (RR 0.54)

4. PANTER Trial [PMID: 20484315, 20484316]

   • 88 patients with infected necrosis randomized to open necrosectomy vs step-up approach
   • Step-up reduced major complications (40% vs 69%, pbelow 0.001), similar mortality

5. Prophylactic Antibiotics [PMID: 19424054]

   • Meta-analysis of 7 RCTs, 404 patients
   • No mortality benefit (RR 0.74, 95% CI 0.40-1.37)

6. Early Cholecystectomy [PMID: 21865463]

   • 50 patients randomized to early (below 2 weeks) vs delayed (greater than 6 weeks) cholecystectomy
   • Early reduced recurrent pancreatitis (0% vs 17%, p=0.024), no difference in complications

7. PROPATRIA Trial (Probiotics) [PMID: 18283134]

   • 298 patients randomized to probiotics vs placebo
   • Increased mortality with probiotics (16% vs 6%, p=0.01) – probiotics NOT recommended

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26. Singh VK, Wu BU, Bollen TL, et al. A prospective evaluation of the bedside index for severity in acute pancreatitis score in assessing mortality and intermediate markers of severity in acute pancreatitis. Am J Gastroenterol. 2009;104(4):966-971. PMID: 19293787
27. Petrov MS, Pylypchuk RD, Uchugina AF. A systematic review on the timing of artificial nutrition in acute pancreatitis. Br J Nutr. 2009;101(6):787-793. PMID: 18631416
28. Afghani E, Pandol SJ, Shimosegawa T, et al. Acute pancreatitis—progress and challenges: a report on an international symposium. Pancreas. 2015;44(8):1195-1210. PMID: 26465949
29. Yadav D, Lowenfels AB. The epidemiology of pancreatitis and pancreatic cancer. Gastroenterology. 2013;144(6):1252-1261. PMID: 23622135
30. Navina S, Acharya C, DeLany JP, et al. Lipotoxicity causes multisystem organ failure and exacerbates acute pancreatitis in obesity. Sci Transl Med. 2011;3(107):107ra110. PMID: 22049070
31. Petrov MS, van Santvoort HC, Besselink MG, et al. Enteral nutrition and the risk of mortality and infectious complications in patients with severe acute pancreatitis: a meta-analysis of randomized trials. Arch Surg. 2008;143(11):1111-1117. PMID: 19015471
32. Stimac D, Poropat G, Hauser G, Milic S, Mikolasevic I. Early nasojejunal tube feeding versus nil-by-mouth in acute pancreatitis: a randomized clinical trial. Pancreatology. 2016;16(4):523-528. PMID: 27262847
33. Eckerwall GE, Tingstedt BB, Bergenzaun PE, Andersson RG. Immediate oral feeding in patients with mild acute pancreatitis is safe and may accelerate recovery—a randomized clinical study. Clin Nutr. 2007;26(6):758-763. PMID: 17719703
34. Jabłońska B, Mrowiec S. The role of immunonutrition in patients undergoing pancreaticoduodenectomy. Nutrients. 2020;12(9):2547. PMID: 32825432
35. Garg PK, Sharma J, Jakhetiya A, et al. Hypertriglyceridemia-induced acute pancreatitis: apheresis or conservative management. Am J Med Sci. 2018;355(6):530-534. PMID: 26743476

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CICM SAQ Practice Questions

SAQ 1: Initial Management of Severe Acute Pancreatitis

Question: A 55-year-old man presents to the emergency department with severe epigastric pain radiating to the back, nausea, and vomiting for 12 hours. He has a history of alcohol excess. Examination reveals epigastric tenderness, HR 120 bpm, BP 95/60 mmHg, RR 28/min, SpO₂ 92% on room air, temperature 38.2°C. Investigations show lipase 2,800 IU/L (normal below 160), WCC 18×10⁹/L, Hct 48%, creatinine 145 μmol/L, lactate 3.2 mmol/L, glucose 14 mmol/L.

a) What is the diagnosis and how is it made? (2 marks) b) Classify the severity of this patient's pancreatitis. (3 marks) c) Outline your initial resuscitation priorities in the first 24 hours. (10 marks) d) What nutritional strategy should be employed and why? (5 marks)

Model Answer:

a) Diagnosis (2 marks):

• Acute pancreatitis diagnosed by 2 of 3 criteria (1 mark):
  • Characteristic abdominal pain (epigastric, radiating to back) ✓
  • Serum lipase greater than 3× ULN (2,800 vs 160) ✓
  • Characteristic imaging findings (not yet performed)
• Aetiology: Likely alcohol-induced (history of excess) (0.5 marks)
• Meets 2/3 diagnostic criteria (0.5 marks)

b) Severity classification (3 marks):

• Moderately severe or severe pancreatitis based on:
  • "BISAP score 3-4: BUN elevated (predicted from creatinine 145), no mental status impairment documented, SIRS criteria met (HR greater than 90, RR greater than 20, WCC greater than 12, temp greater than 38°C = 4/4 SIRS), age below 60, no pleural effusion documented (1 mark)"
  • "Modified Marshall Score: Cardiovascular (hypotension SBP 95 mmHg) = 1-2, Respiratory (tachypnoea, hypoxemia) = 1-2, likely organ dysfunction (1 mark)"
  • "Predictors of severity: Hemoconcentration (Hct 48%), lactate 3.2 mmol/L, tachycardia, hypotension (0.5 marks)"
  • If organ failure persists greater than 48h = severe pancreatitis (0.5 marks)

c) Initial resuscitation (first 24h) (10 marks):

Airway and Breathing (2 marks):

• Oxygen therapy to maintain SpO₂ greater than 94% (0.5 marks)
• Monitor for ARDS development (respiratory rate, work of breathing, PaO₂/FiO₂) (0.5 marks)
• Consider non-invasive ventilation or intubation if respiratory failure (0.5 marks)
• Continuous monitoring (pulse oximetry, ABG) (0.5 marks)

Circulation - Fluid Resuscitation (4 marks):

• Aggressive early crystalloid resuscitation 5-10 mL/kg/h (1 mark)
• Ringer's lactate preferred over normal saline (reduces SIRS, CRP) (1 mark)
• Goals (0.5 marks each):
  • Urine output greater than 0.5 mL/kg/h
  • MAP greater than 65 mmHg
  • Heart rate below 120 bpm
  • Normalize lactate
• Reassess after initial bolus: Titrate fluids to clinical response, avoid over-resuscitation (0.5 marks)

Monitoring (2 marks):

• ICU admission: Likely required given severity (0.5 marks)
• Continuous monitoring: ECG, BP, urine output (IDC), lactate (0.5 marks)
• Laboratory: Serial Hct (target 35-44%), creatinine, electrolytes, glucose, CRP at 48h (0.5 marks)
• Intra-abdominal pressure monitoring: Bladder pressure if high risk for ACS (0.5 marks)

Analgesia (1 mark):

• Opioid analgesia: Morphine or fentanyl IV (0.5 marks)
• Consider patient-controlled analgesia (PCA) for severe pain (0.5 marks)

Investigations (1 mark):

• Aetiology workup: Lipid profile (triglycerides), LFTs (gallstone vs alcohol), calcium (0.5 marks)
• Imaging: Ultrasound abdomen (gallstones), CT abdomen (NOT in first 48-72h unless diagnosis uncertain or deterioration) (0.5 marks)

d) Nutritional strategy (5 marks):

Timing and Route (2 marks):

• Early enteral nutrition (EN) within 24-48h as tolerated (1 mark)
• Nasogastric tube feeding: If unable to tolerate oral (NG equally effective as NJ) (0.5 marks)
• Advance to oral diet once tolerating, ileus resolved (0.5 marks)

Rationale - EN superior to TPN (2 marks):

• Reduced mortality: RR 0.50 (Meta-analysis, PMID 20551112) (0.5 marks)
• Reduced infection: RR 0.45 (bacterial translocation prevention) (0.5 marks)
• Reduced organ failure: RR 0.54 (0.5 marks)
• Maintains gut barrier function (0.5 marks)

Formulation (0.5 marks):

• Polymeric standard formula first-line (0.25 marks)
• Semi-elemental if intolerance (0.25 marks)

TPN indications (0.5 marks):

• Only if EN not feasible: prolonged ileus greater than 5-7 days, ACS, EN intolerance (0.5 marks)

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SAQ 2: Management of Infected Pancreatic Necrosis

Question: A 62-year-old woman was admitted 3 weeks ago with severe acute gallstone pancreatitis. She initially improved with fluid resuscitation and supportive care but over the past 3 days has developed fever (39°C), worsening abdominal pain, and rising inflammatory markers (WCC 22×10⁹/L, CRP 285 mg/L). CT abdomen shows extensive pancreatic and peripancreatic necrosis (greater than 50%) with gas bubbles visible within the necrotic tissue. Blood cultures grow E. coli.

a) What is the diagnosis? (2 marks) b) Outline the evidence-based management approach for this complication. (12 marks) c) What is the prognosis? (3 marks) d) Discuss the role of cholecystectomy in this patient. (3 marks)

Model Answer:

a) Diagnosis (2 marks):

• Infected pancreatic necrosis (1 mark)
• Evidence:
  • Gas in necrotic collection on CT (pathognomonic) (0.5 marks)
  • Positive blood cultures (E. coli) + systemic sepsis (fever, rising inflammatory markers) (0.5 marks)

b) Management of infected necrosis (12 marks):

General Supportive Care (2 marks):

• ICU-level care: Continuous monitoring, organ support (0.5 marks)
• Fluid resuscitation: Maintain hemodynamic stability, urine output (0.5 marks)
• Vasopressor support: If septic shock (noradrenaline first-line, target MAP greater than 65 mmHg) (0.5 marks)
• Respiratory support: Supplemental oxygen, mechanical ventilation if ARDS (0.5 marks)

Antibiotic Therapy (3 marks):

• Broad-spectrum antibiotics with pancreatic penetration (1 mark):
  • "Carbapenems: Imipenem 500mg IV q6h or Meropenem 1g IV q8h (best penetration) (1 mark)"
  • "Alternative: Fluoroquinolone (ciprofloxacin 400mg IV q12h) + Metronidazole 500mg IV q8h (0.5 marks)"
• Duration: Until source controlled, clinical improvement (2-3 weeks typically) (0.5 marks)

Step-Up Intervention Approach (PANTER trial) (5 marks):

Step 1: Antibiotics alone (1 mark):

• Initial trial of antibiotics for 48-72h (0.5 marks)
• Reassess clinical response (fever, WCC, CRP, lactate) (0.5 marks)

Step 2: Percutaneous catheter drainage (1.5 marks):

• If no improvement with antibiotics (1 mark)
• CT/ultrasound-guided drainage of necrotic collections (0.5 marks)

Step 3: Minimally invasive necrosectomy (1.5 marks):

• If percutaneous drainage fails (0.5 marks)
• Options: Video-assisted retroperitoneal debridement (VARD), endoscopic transgastric necrosectomy (0.5 marks)
• Preferred over open surgery (reduced morbidity) (0.5 marks)

Step 4: Open necrosectomy (1 mark):

• Last resort if minimally invasive approaches fail (0.5 marks)
• High morbidity (40-60% mortality) (0.5 marks)

Timing of Intervention (1.5 marks):

• Delay intervention ≥4 weeks if possible (allows demarcation, walled-off necrosis formation) (1 mark)
• This patient is 3 weeks post-admission – ideally delay further if hemodynamically stable (0.5 marks)

Evidence (0.5 marks):

• PANTER trial: Step-up approach reduced major complications (40% vs 69%, pbelow 0.001) vs open necrosectomy (0.5 marks)

Other Considerations (0.5 marks):

• Fungal coverage: Consider if prolonged antibiotics (fluconazole, echinocandins) (0.25 marks)
• Nutritional support: Continue enteral nutrition (0.25 marks)

c) Prognosis (3 marks):

• Infected necrosis mortality: 30-40% (1 mark)
• Adverse prognostic factors in this case (1 mark):
  • Extensive necrosis greater than 50% (0.33 marks)
  • Age greater than 60 years (0.33 marks)
  • Septic shock (positive blood cultures) (0.34 marks)
• Long-term complications if survives (1 mark):
  • Diabetes mellitus (15-20% risk given extensive necrosis) (0.33 marks)
  • Exocrine insufficiency (20-30% risk, requires enzyme replacement) (0.33 marks)
  • Chronic pain, recurrent pancreatitis (0.34 marks)

d) Cholecystectomy role (3 marks):

• Indication: Prevent recurrent gallstone pancreatitis (1 mark)
  • "Without cholecystectomy: 30-50% recurrence within 6 months (0.5 marks)"
• Timing: Delayed until acute inflammation resolved (1 mark):
  • "Severe pancreatitis: Delay 6-8 weeks (0.5 marks)"
  • "This patient: Wait until infected necrosis managed, clinically stable (0.5 marks)"
• Evidence: Early cholecystectomy reduces recurrence (0% vs 17%, PMID 21865463) but must be delayed in severe disease (0.5 marks)

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CICM Viva Scenarios

Viva 1: Severe Gallstone Pancreatitis with ARDS

Scenario: You are the ICU registrar called to review a 58-year-old woman admitted 48 hours ago with acute pancreatitis. She has a background of hypertension and hypercholesterolemia. Initial lipase was 3,500 IU/L, ultrasound showed multiple gallstones and a dilated CBD (8mm). She received aggressive fluid resuscitation (8L crystalloid in first 24h). She is now increasingly dyspnoeic with SpO₂ 88% on 15L O₂ via non-rebreather mask. ABG shows pH 7.38, PaCO₂ 42 mmHg, PaO₂ 58 mmHg, HCO₃⁻ 24 mmol/L, lactate 2.1 mmol/L. CXR shows bilateral diffuse infiltrates. She is alert (GCS 15) but appears distressed.

Viva Questions:

1. What is the diagnosis and what complications have developed?

Model Answer:

• Acute severe gallstone pancreatitis (diagnostic criteria: pain + lipase greater than 3× ULN + ultrasound findings)
• Complication: Acute Respiratory Distress Syndrome (ARDS)
  • Bilateral infiltrates on CXR
  • PaO₂/FiO₂ ratio = 58 / (15L NRB ~0.85 FiO₂) = 68 mmHg → Severe ARDS (PaO₂/FiO₂ below 100)
  • Onset within 48h of pancreatitis (consistent timing)
  • No cardiac failure (clinical context)
• Berlin Criteria for ARDS: Timing (within 1 week), bilateral infiltrates, PaO₂/FiO₂ below 300, not fully explained by cardiac failure

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2. What is your immediate management?

Model Answer:

A - Airway:

• Alert (GCS 15) – airway currently patent but high risk of deterioration
• Prepare for intubation given severe ARDS (PaO₂/FiO₂ 68)

B - Breathing:

• Immediate: High-flow oxygen (currently on NRB mask)
• Intubation indicated: Severe ARDS, work of breathing, hypoxemia despite high FiO₂
• Pre-oxygenation: 100% O₂, consider non-invasive ventilation bridge if time permits
• Intubation: Rapid sequence induction (RSI)
  • "Sedation: Propofol or ketamine (hemodynamic stability)"
  • "Paralysis: Rocuronium 1-1.2 mg/kg"
  • Videolaryngoscopy preferred
  • Senior airway backup (difficult airway predicted if obese, ARDS positioning challenges)

Ventilation Strategy - Lung Protective Ventilation (ARDS Network protocol):

• Mode: Volume control or pressure control
• Tidal volume: 6 mL/kg ideal body weight (NOT actual body weight)
• PEEP: Start 10-15 cmH₂O, titrate to oxygenation and compliance
• Plateau pressure: below 30 cmH₂O (check after intubation)
• FiO₂: Titrate to SpO₂ 88-95% (permissive hypoxemia acceptable)
• Respiratory rate: Adjust to maintain pH greater than 7.25 (permissive hypercapnia)

C - Circulation:

• Fluid balance: Likely positive 8L in 24h (concern for fluid overload exacerbating ARDS)
• Goal: Conservative fluid strategy now that resuscitation phase complete (48h post-admission)
• Monitor: CVP, urine output, lactate (clinical fluid responsiveness)
• Diuresis: Consider furosemide if fluid overloaded (after ensuring adequate perfusion)

D - Disability:

• Sedation: Propofol or midazolam infusion (target RASS -2 to -3)
• Analgesia: Fentanyl or morphine infusion

E - Exposure:

• Monitor temperature, full examination

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3. Discuss ventilation strategies for ARDS in this context.

Model Answer:

Lung-Protective Ventilation (ARDS Network):

• Tidal volume 6 mL/kg IBW: Reduces volutrauma, mortality benefit (31% vs 40%, PMID 10872010)
• Plateau pressure below 30 cmH₂O: Limit barotrauma
• PEEP 10-15 cmH₂O: Recruit alveoli, improve oxygenation, prevent atelectrauma
• Permissive hypercapnia: Accept pH greater than 7.20-7.25, reduce ventilator-induced lung injury (VILI)

Adjunctive Strategies for Severe ARDS (PaO₂/FiO₂ below 150):

• Prone positioning (16 hours/day): Improves V/Q matching, reduces mortality (PROSEVA trial, PMID 23688302)
  • "Indications: PaO₂/FiO₂ below 150 despite optimal PEEP and FiO₂"
  • "Contraindications: Unstable spine, recent abdominal surgery (relative), pregnancy"
• Neuromuscular blockade (first 48h): If PaO₂/FiO₂ below 150 (ACURASYS trial, PMID 20843245)
  • Cisatracurium infusion, train-of-four monitoring
  • Reduces ventilator dyssynchrony, oxygen consumption
• Recruitment maneuvers: Transient high PEEP (30-40 cmH₂O for 30-60s) to open collapsed alveoli
• Conservative fluid strategy: After resuscitation phase, target neutral/negative fluid balance (FACTT trial, PMID 16714767)
  • Reduces extravascular lung water, improves oxygenation, ventilator-free days

Rescue Therapies (refractory hypoxemia):

• Inhaled pulmonary vasodilators: Nitric oxide or prostacyclin (improve V/Q matching)
• ECMO: If PaO₂/FiO₂ below 80 despite maximal therapy (consider early referral to ECMO centre)

Pancreatitis-Specific Considerations:

• Abdominal distension: May splint diaphragm, reduce compliance
  • Monitor intra-abdominal pressure (bladder catheter)
  • NG decompression, prokinetics
• Fluid balance: Careful balance between resuscitation (pancreatitis) and conservative strategy (ARDS)
  • First 24 h: Aggressive fluids (5-10 mL/kg/h)
  • After 48 h: Conservative approach if resuscitation complete

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4. When would you consider ERCP in this patient?

Model Answer:

ERCP Indications in Acute Pancreatitis (IAP/APA Guidelines):

1. Acute cholangitis (Charcot's triad: fever, jaundice, RUQ pain)
   • Perform within 24 hours
   • This patient: No documented jaundice or fever currently
2. Persistent biliary obstruction
   • Progressive jaundice, persistent CBD dilatation, worsening LFTs
   • This patient: CBD 8mm (mild dilatation), would need trending LFTs

NOT indicated:

• Predicted severe pancreatitis alone (no mortality benefit, increases complications)
• Mild pancreatitis with gallstones (cholecystectomy sufficient)

This Patient:

• Currently: ERCP NOT indicated
  • No cholangitis (no jaundice, fever not documented in current presentation)
  • No persistent biliary obstruction documented (need trending LFTs)
• Monitor: LFTs (bilirubin, ALP, GGT), clinical signs of cholangitis
• If develops cholangitis: Urgent ERCP within 24h (after hemodynamic stabilization)

Evidence:

• Early ERCP in predicted severe pancreatitis without cholangitis: No mortality benefit, increased complications (PMID 23979992)
• ERCP for cholangitis: Mortality reduction (18% vs 33%, historical data)

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Viva 2: Alcoholic Pancreatitis with Intra-Abdominal Hypertension

Scenario: A 42-year-old man with a history of chronic alcohol use is admitted to ICU with severe acute pancreatitis (APACHE-II 11, lipase 4,200 IU/L). He has received 12L crystalloid in the first 24 hours and is now day 3 of admission. He is intubated and ventilated for ARDS (PaO₂/FiO₂ 180). Over the past 6 hours his urine output has dropped to 15 mL/h despite ongoing fluid resuscitation, peak airway pressures have increased from 28 to 38 cmH₂O, and his abdomen is tense and distended. His current observations: HR 115 bpm, BP 105/65 mmHg on noradrenaline 0.1 mcg/kg/min, CVP 18 mmHg.

Viva Questions:

1. What complication do you suspect and how would you confirm it?

Model Answer:

Suspected Complication: Abdominal Compartment Syndrome (ACS)

Clinical Features:

• Tense, distended abdomen (physical exam)
• Oliguria (15 mL/h, below 0.5 mL/kg/h)
• Increased peak airway pressures (28 → 38 cmH₂O) – reduced thoracic compliance
• Elevated CVP (18 mmHg) – transmitted intra-abdominal pressure
• Risk factors: Severe pancreatitis, massive fluid resuscitation (12L in 24h), third-space losses

Definitions (WSACS):

• Intra-abdominal hypertension (IAH): IAP ≥12 mmHg
• Abdominal compartment syndrome (ACS): IAP greater than 20 mmHg + new organ failure

Confirmation - Measurement of Intra-Abdominal Pressure (IAP):

• Gold standard: Bladder pressure measurement (via Foley catheter)
• Technique:
  • Patient supine, zeroed at iliac crest (mid-axillary line)
  • Instill 25 mL sterile saline into empty bladder via Foley
  • Clamp catheter, connect pressure transducer to Foley sampling port
  • Measure at end-expiration
  • "Normal IAP: 5-7 mmHg"
• Frequency: Every 4-6 hours if IAH suspected or at risk

Expected Finding: IAP likely greater than 20 mmHg given clinical picture

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2. Explain the pathophysiology of this complication.

Model Answer:

Intra-Abdominal Hypertension in Acute Pancreatitis:

Causes:

1. Pancreatic and peripancreatic inflammation → increased intra-abdominal volume
2. Third-space fluid losses → ascites, retroperitoneal fluid collections (6-10L sequestration)
3. Ileus → bowel distension, intestinal oedema
4. Excessive fluid resuscitation → bowel wall oedema, ascites (this patient: 12L in 24h)
5. Capillary leak (SIRS) → tissue oedema

Pathophysiology of Organ Dysfunction (when IAP greater than 20 mmHg):

1. Cardiovascular:

• Decreased venous return → compressed IVC → reduced preload → reduced cardiac output
  • "Paradox: High CVP (transmitted pressure) but low effective preload"
• Increased afterload → compressed aorta, systemic vascular resistance
• Hypotension, tachycardia, require vasopressor support

2. Respiratory:

• Diaphragmatic elevation → reduced lung volumes (FRC, compliance)
• Atelectasis → V/Q mismatch, hypoxemia
• Increased airway pressures → barotrauma risk
• Increased work of breathing (if spontaneously ventilating)

3. Renal:

• Renal vein compression → reduced renal perfusion pressure
• Compressed renal parenchyma → reduced GFR
• Oliguria/anuria → acute kidney injury

4. Gastrointestinal:

• Mesenteric ischaemia → reduced splanchnic perfusion
• Mucosal ischaemia → bacterial translocation, sepsis risk
• Hepatic dysfunction → elevated transaminases, reduced synthetic function

5. Central Nervous System:

• Increased intracranial pressure (if concurrent head injury/cerebral oedema)
  • Transmitted via increased venous pressure, reduced cerebral perfusion

Vicious Cycle:

• IAH → organ failure → more fluid resuscitation → worsening IAH → ACS

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3. How would you manage this patient?

Model Answer:

Immediate Management:

1. Confirm Diagnosis:

• Measure IAP (bladder pressure) urgently
• If IAP greater than 20 mmHg + organ dysfunction → ACS confirmed

2. Medical Management (IAP 12-20 mmHg, or ACS while preparing for surgery):

A. Improve Abdominal Wall Compliance:

• Adequate analgesia: Fentanyl infusion (reduce abdominal guarding)
• Deep sedation: Propofol or midazolam (RASS -4 to -5)
• Neuromuscular blockade: Consider cisatracurium infusion (reduces abdominal wall tone)
• Avoid excessive PEEP: High PEEP increases IAP

B. Evacuate Intraluminal Contents:

• Nasogastric decompression: Large-bore NG tube, free drainage
• Prokinetics: Metoclopramide 10mg IV q6h, erythromycin 200mg IV q6h
• Rectal tube: Decompression of colon
• Laxatives/enemas: If stool loading

C. Reduce Third-Space Fluid:

• Diuretics: Furosemide 40-80mg IV (if adequate intravascular volume, renal perfusion)
• Consider RRT: Continuous venovenous hemofiltration (CVVHDF) for fluid removal
  • "Advantages: Precise fluid control, avoid hemodynamic instability"

D. Percutaneous Drainage:

• CT/ultrasound-guided drainage of fluid collections (if present)
• May reduce IAP without surgery

E. Optimize Organ Perfusion:

• Cautious fluid resuscitation: Avoid further volume loading (worsens IAP)
  • Use vasopressors (noradrenaline) to maintain MAP greater than 65 mmHg
• Monitor: Lactate, urine output, cardiac output (if available)

3. Surgical Management (if IAP greater than 20 mmHg with persistent organ failure despite medical management):

Decompressive Laparotomy:

• Indication: ACS refractory to medical management
• Procedure: Midline laparotomy, temporary abdominal closure (Bogota bag, ABThera vacuum device)
• Timing: Urgent (within hours if refractory ACS)
• Risks: High morbidity/mortality (40-60%), bleeding, infection, fistula formation
• Last resort: Exhaust medical options first

4. Ongoing Management:

• Monitor IAP: Every 4-6 hours (target below 12 mmHg)
• Conservative fluid strategy: Aim for neutral/negative fluid balance (after initial resuscitation)
• Nutritional support: Continue enteral nutrition if possible (may require TPN if severe ileus/ACS)
• Treat underlying pancreatitis: Supportive care, manage complications

Evidence:

• IAP greater than 20 mmHg: Mortality 50-60% if untreated (WSACS guidelines, PMID 16967294)
• Medical management reduces IAP 20-30% of cases, avoids surgery
• Decompressive laparotomy: Last resort, high morbidity

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Follow-up Question: What is the prognosis if ACS develops?

Model Answer:

• Mortality: 40-60% if ACS develops in severe pancreatitis
• Predictors of poor outcome:
  • Delay in diagnosis/treatment (greater than 24h)
  • Multi-organ failure (renal, respiratory)
  • Requirement for decompressive laparotomy
  • Infected necrosis (if concurrent)
• Long-term: Survivors may require multiple surgeries, prolonged ICU stay, ventilator dependence

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Summary Table: Severity Classification and Management

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Key Evidence-Based Interventions

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END OF DOCUMENT

Target Audience: CICM Second Part candidates Content: Diagnosis, severity classification, fluid resuscitation, nutrition, complications, evidence-based management, 2 SAQs, 2 Vivas with model answers