Treatment of Acute Pancreatitis

1. Initial Assessment and Severity Stratification

• BISAP score (most practical): BUN >25 mg/dL, impaired mental status, SIRS, age >60 years, pleural effusion. Score ≥3 predicts substantially increased in-hospital mortality.
• APACHE II ≥8 at 24 h
• Hemoconcentration (Hct >44%) and admission BUN >20 mg/dL
• Persistent SIRS at 24 h is the strongest predictor of organ failure and necrosis
• CRP >100 mg/L during hospitalization suggests severity

• Low BISAP, no SIRS → regular ward
• Persistent SIRS or comorbidities → step-down unit
• High BISAP, non-responder to IV fluids, organ failure → ICU

2. Fluid Resuscitation (Cornerstone of Treatment)

• Preferred fluid: Lactated Ringer's (LR) - shown to lower CRP levels, reduce systemic inflammation, and cause less metabolic acidosis compared to normal saline. It is more physiologic and may have anti-inflammatory properties.
• Dosing strategy: Recent RCT evidence has shifted practice toward a goal-directed rather than fixed aggressive approach:
  • Bolus: 10-15 mL/kg, then 1.5-3 mL/kg/h, titrated to response
  • An overly aggressive strategy (20 mL/kg bolus + 3 mL/kg/h) was associated with fluid overload without improvement in outcomes
  • Target: HR normalization, MAP adequate, urine output >0.5 mL/kg/h; in severe cases, CVP 8-12 mmHg, mixed venous O2 sat ≥70%
• Monitoring response: Check hematocrit and BUN every 8-12 h. A falling BUN and Hct within the first 12-24 h confirms adequate resuscitation. A rising BUN is associated with higher in-hospital mortality.
• Avoid fluid overload: Watch for tachypnea, hypoxia, edema, pleural effusions; diurese once hypovolemia resolves.

3. Analgesia

• IV opioid analgesics are the standard for pain control. There is no convincing evidence to prefer one opioid agent over another (e.g., morphine vs. hydromorphone).
• The old contraindication to morphine (sphincter of Oddi spasm) is not clinically significant.
• NSAIDs and rectal indomethacin have roles in post-ERCP pancreatitis prevention but are not the primary analgesic in management.

4. Nutrition

• ~2-fold reduction in total and pancreatic infectious complications
• ~2.5-fold reduction in risk of death
• Lower rates of infected peripancreatic necrosis (OR 0.28), single organ failure (OR 0.25), MOF (OR 0.41) vs PN

5. Antibiotics

• Prophylactic antibiotics are NOT recommended - sterile necrosis does not benefit, and prophylaxis selects for resistant organisms.
• Do not use probiotics - a multicenter RCT showed mortality more than doubled in the probiotic group, possibly from intestinal ischemia.
• When to use antibiotics:
  • Documented infected pancreatic necrosis (radiographic or positive fluid culture)
  • Clinical sepsis with a clear infectious source
  • Cholangitis
• Antibiotic choice for infected necrosis: Carbapenems (imipenem, meropenem) penetrate pancreatic necrosis better than cephalosporins or fluoroquinolones.
• Goal of antibiotics in infected necrosis: Stabilize the patient and defer intervention until at least 4 weeks after onset to allow collection to mature and wall off.

6. Etiology-Directed Treatment

Gallstone Pancreatitis

• Abdominal ultrasound should be performed in all patients to assess for biliary etiology.
• ERCP is indicated only if there is: ascending cholangitis OR biliary obstruction (not for uncomplicated gallstone pancreatitis alone).
• ERCP should be performed within 24-48 h if cholangitis is present.
• Cholecystectomy during the same admission is recommended for mild AP to prevent recurrence. Endoscopic biliary sphincterotomy is an alternative for poor surgical candidates.

Hypertriglyceridemia (TG >1000 mg/dL)

• Insulin infusion (drives triglyceride uptake into cells), fibrates, and plasmapheresis in severe cases.
• Long-term: fibrate therapy, dietary fat restriction.

Hypercalcemia

• Treat the underlying cause (hyperparathyroidism, malignancy).

Drug-induced

• Discontinue the causative agent.

7. Management of Necrotizing Pancreatitis and Complications

Sterile Necrosis

• Conservative management. No surgical intervention unless symptomatic sterile necrosis persists >8 weeks (e.g., gastric outlet obstruction, pain, disconnected pancreatic duct).
• CT-guided FNA can confirm sterility if clinical deterioration occurs.

Infected Necrosis - The "Step-Up Approach"

1. Antibiotics to stabilize + defer
2. Minimally invasive drainage first: endoscopic or percutaneous drainage (wait at least 4 weeks for the collection to "wall off" - walled-off necrosis is more amenable to drainage)
3. Step up to endoscopic necrosectomy or surgical (video-assisted retroperitoneal debridement/VARD) only if drainage alone fails

• 75% mortality in first 2 weeks
• 45% mortality at 2-4 weeks
• 8% mortality if delayed beyond 30 days

Emergent indications (regardless of timing):

• Intestinal ischemia
• Perforated viscus
• Acute uncontrolled hemorrhage
• Abdominal compartment syndrome

8. Monitoring and Discharge

• Serial vitals, urine output every 6-8 h
• Hematocrit + BUN every 8-12 h
• Lipase/amylase need not be serially tracked (levels don't correlate with severity)
• CT scan: not routinely indicated at presentation; use if diagnosis uncertain, failure to improve by 72 h, or to assess for complications
• Patients with mild AP can be discharged when pain is controlled and oral intake is tolerated

Recent Guideline Update (2025)

1. Fluid resuscitation with LR - goal-directed, not reflexively aggressive
2. Oral or enteral nutrition early - NPO only when truly needed
3. No prophylactic antibiotics
4. ERCP only for cholangitis/obstruction, not routine
5. Delayed (>4 weeks), step-up, minimally invasive approach to necrotizing pancreatitis