Acute Pancreatitis
Inflammation of the pancreas -ranges from mild edematous disease (80%, self-limited) to severe necrotizing pancreatitis (20%, multiorgan failure, ICU mortality 15–30%). Aggressive early fluids + pain control + early feeding.
🔍 Overview
Diagnosis (Revised Atlanta -need 2 of 3)
- Abdominal pain consistent with pancreatitis (epigastric, radiating to back, worse supine)
- Lipase ≥ 3× upper limit of normal (more sensitive and specific than amylase)
- Imaging findings on CT/MRI/US (only needed if diagnosis unclear from above two)
Do NOT routinely CT on admission. CT is normal in 15–30% of early pancreatitis. Reserve CT for: diagnostic uncertainty, no improvement at 48–72h, or suspecting complications (necrosis, abscess, pseudocyst).
Etiology -"I GET SMASHED"
| Letter | Cause | % of Cases |
|---|---|---|
| I | Idiopathic | ~10–15% |
| G | Gallstones | ~40% (most common) |
| E | Ethanol | ~30% (2nd most common) |
| T | Trauma / tumor | ~2–5% |
| S | Steroids / scorpion stings | Rare |
| M | Mumps / autoimmune | Rare |
| A | Autoimmune (IgG4) | ~2% |
| S | Sphincter of Oddi dysfunction | Rare |
| H | Hyperlipidemia / Hypercalcemia / Hypothermia | TG > 1000 → ~5% |
| E | ERCP | ~5% post-ERCP |
| D | Drugs (azathioprine, valproic acid, didanosine, mesalamine) | ~2% |
Severity (Revised Atlanta Classification)
| Severity | Definition | Mortality |
|---|---|---|
| Mild (~80%) | No organ failure, no local complications | < 1% |
| Moderately severe (~15%) | Transient organ failure (< 48h) OR local complications (necrosis, pseudocyst, fluid collections) | ~5% |
| Severe (~5%) | Persistent organ failure > 48h (respiratory, renal, cardiovascular) | 15–30% |
BISAP score ≥ 3 within 24h predicts severe disease: BUN > 25, Impaired mental status, SIRS, Age > 60, Pleural effusion.
🚨 Management
Pillars of Management
1. Goal-directed IVF
Lactated Ringer's preferred de-Madaria, 2018. Goal-directed: 1.5 mL/kg/hr initially, titrate to UOP ≥ 0.5 mL/kg/hr, HR < 120, MAP ≥ 65. Reassess at 6h -avoid over-resuscitation (worsens third-spacing, pulmonary edema). Recent data suggests moderate fluids are non-inferior WATERFALL, 2022: aggressive vs moderate fluids → moderate (1.5 mL/kg/hr) was non-inferior with fewer fluid complications.
2. Pain Control
Multimodal analgesia. Acetaminophen IV 1g q6h (scheduled) + fentanyl or hydromorphone IV PRN (morphine is acceptable -the "morphine causes sphincter of Oddi spasm" concern is not clinically significant). Ketorolac 15–30 mg IV q6h if no AKI. PCA if severe.
3. Early Feeding
Start oral diet within 24h if tolerated. Low-fat solid diet (not just clear liquids). Petrov, 2013: early feeding reduces infection, organ failure, and length of stay. NPO is outdated. If oral not tolerated → nasogastric or nasojejunal tube feeding preferred over TPN. TPN only if enteral feeding fails ≥ 5 days.
4. Antibiotics
NOT routine in acute pancreatitis -even if necrosis present. Prophylactic antibiotics for necrotizing pancreatitis do NOT reduce mortality or infection Dellinger, 2007. Only treat infected necrosis (confirmed by FNA with positive gram stain/culture, or gas on CT). Use carbapenems (meropenem) -best pancreatic penetration.
5. Gallstone Pancreatitis
ERCP within 24h ONLY if concurrent cholangitis (fever, jaundice, RUQ pain = Charcot's triad) or persistent biliary obstruction. Otherwise, cholecystectomy during same admission (before discharge) to prevent recurrence PONCHO, 2015.
🔄 Updated Practice: Several old practices have been abandoned: (1) Prophylactic antibiotics do NOT prevent infected necrosis -don't give them. (2) NPO until pain resolves and lipase normalizes is WRONG -start low-fat oral diet as soon as tolerated (early feeding shortens hospital stay). (3) Old teaching said "aggressive" IV fluids (250-500 mL/hr); WATERFALL 2022 showed aggressive LR did not improve outcomes and increased fluid overload. Use goal-directed fluid resuscitation instead (1.5 mL/kg/hr LR, targeting UOP ≥0.5 mL/kg/hr).
Complications
Two questions classify every local complication (Revised Atlanta 2012). First, is there necrosis? That decides whether a drain alone can ever be enough, because solid debris clogs a percutaneous catheter and needs necrosectomy. Second, is it under or over 4 weeks? That decides whether a mature wall exists to drain into. Those two answers produce the four collections below, and they dictate what you are allowed to do.
Local Complications: The Four Collections
| Collection | Timing | What it contains | Management, and why |
|---|---|---|---|
| Acute peripancreatic fluid collection (APFC) | < 4 weeks no necrosis | Fluid only, homogeneous, no defined wall | Leave it alone. Most resolve spontaneously, and instrumenting a sterile collection is the classic way to convert it into an infected one. |
| Pancreatic pseudocyst | > 4 weeks no necrosis | Encapsulated fluid only, defined enhancing wall, no solid debris | Drain only if symptomatic (pain, gastric outlet or biliary obstruction) or infected, by EUS-guided transmural route. Size alone is not an indication: the old "> 6 cm for > 6 weeks" rule is obsolete, because most large pseudocysts still regress and draining an asymptomatic one only risks infecting it. |
| Acute necrotic collection (ANC) | < 4 weeks necrosis | Fluid plus solid necrotic debris, heterogeneous, no wall yet | Supportive care. With no wall it will not hold a drain, and solid debris clogs a percutaneous catheter, so early drainage tends to leak and buy nothing. |
| Walled-off necrosis (WON) | > 4 weeks necrosis | Encapsulated fluid plus solid debris, mature wall | Intervene only if infected, or if sterile but causing persistent pain, obstruction, or failure to thrive. That mature wall is what makes drainage and necrosectomy safe, and is the whole reason to wait 4 weeks. |
Infected Necrosis
The commonest cause of late death in pancreatitis, and the one complication where timing beats aggression.
- Suspect it after the first week. It complicates about a third of necrotizing pancreatitis, peaking at weeks 2 to 4 as gut organisms translocate. The trigger to act is clinical deterioration, or failure to improve after 7 to 10 days.
- Gas within the collection on CT is diagnostic. Routine FNA is no longer recommended: it carries a real false-negative rate and rarely changes a decision you can already make clinically.
- Choose antibiotics that actually reach necrotic tissue, since poor perfusion excludes most agents: a carbapenem, or a fluoroquinolone plus metronidazole, narrowed once cultures return. In a stable patient antibiotics alone may be the entire treatment: in POINTER, 2021, 19 of 49 postponed-arm patients (39%) were cured without any drainage at all.
- Step up, never straight to open surgery. PANTER, 2010 compared a step-up approach (drain first, minimally invasive necrosectomy only if no improvement) against open necrosectomy: major complications or death 40% vs 69% (RR 0.57, 95% CI 0.38 to 0.87, P = 0.006), driven by new-onset organ failure 12% vs 42%. Mortality itself did not differ (19% vs 16%), and about 35% never needed necrosectomy because the drain alone was definitive.
- Postpone the drain if the patient will tolerate it. POINTER's primary endpoint was negative (no difference in complications or mortality), so the case for waiting rests on fewer interventions, not on survival. Practically: antibiotics and wait for the wall, but early drainage remains legitimate in a deteriorating patient, because it did not cause harm.
- Do not intervene on sterile necrosis unless it is symptomatic. Extent of necrosis alone never justifies intervention.
Systemic and Vascular Complications
| Complication | Timing | Management, and why |
|---|---|---|
| Persistent organ failure defines severe disease | First week | SIRS progressing to organ failure beyond 48 hours is what defines severe disease on the Revised Atlanta scale and what kills in the early mortality peak. Expect ARDS, AKI, and distributive shock. Late deaths are a separate mechanism: infected necrosis and sepsis. |
| Abdominal compartment syndrome | First days, with resuscitation | Sustained intra-abdominal pressure > 20 mmHg with new organ dysfunction (WSACS); intra-abdominal hypertension starts at ≥ 12 (grade I 12 to 15, II 16 to 20, III 21 to 25, IV > 25). Driven by ileus, retroperitoneal edema, ascites, and over-resuscitation, which is a second reason to keep fluids moderate. Measure it rather than eyeballing it: bladder pressure with ≤ 25 mL instilled saline, supine, at end-expiration, transducer at the midaxillary line. Decompress medically first (NG and rectal decompression, prokinetics, sedation and if needed paralysis, percutaneous drainage of tense ascites, stop the fluid), since each lowers pressure without opening the abdomen. Decompressive laparotomy is reserved for overt ACS, because an open abdomen carries fistula, hernia, and failed-closure morbidity you cannot take back. |
| Splanchnic vein thrombosis ~22% of necrotizing pancreatitis | Variable | Most often the splenic vein, producing left-sided portal hypertension with isolated gastric varices. Anticoagulation is individualized against bleeding risk rather than automatic. Splenectomy for refractory variceal bleeding. |
| Splenic artery pseudoaneurysm | Weeks, with necrosis | Enzymatic erosion of the vessel wall. The warning signs are a sentinel bleed, an unexplained hemoglobin drop, or blood in a drain. Treat by angioembolization, not laparotomy, because operating in an inflamed necrotic field carries far higher mortality. |
| Disconnected pancreatic duct syndrome | Late, with necrosis | Necrosis of the neck transects the duct, so a viable upstream tail keeps secreting into a dead end. Suspect it when a collection recurs every time the drain comes out. It needs an indefinite transmural stent or surgery, and missing it means an endless cycle of re-drainage. |
| Exocrine insufficiency and new diabetes | Months | Common after necrotizing disease, so arrange follow-up rather than discharging to nobody. Check fecal elastase for exocrine failure and start pancreatic enzyme replacement if low; screen for new diabetes. |
📋 Clinical Example -Acute Pancreatitis Severity Assessment
Patient: 52M heavy drinker, epigastric pain radiating to back × 12h, lipase 2,400 (>3× ULN), HR 105, Cr 1.8.
Initial management:
- Goal-directed IV LR at 1.5 mL/kg/hr (WATERFALL, 2022 -'aggressive' fluid strategy did not improve outcomes and increased fluid overload. Use goal-directed approach: target UOP ≥ 0.5 mL/kg/hr, trending BUN and hematocrit). NOT NS -LR reduces SIRS in pancreatitis.
- NPO initially → start low-fat diet as soon as tolerated (early feeding improves outcomes -do NOT wait for pain to fully resolve or lipase to normalize).
- Pain: IV hydromorphone (Dilaudid) 0.5–1mg q3h PRN. Morphine is safe despite old myths about sphincter of Oddi spasm.
- NO prophylactic antibiotics (even in severe pancreatitis -doesn't prevent infected necrosis).
Severity assessment at 48h:
- BISAP score: BUN > 25 (+1), impaired mental status (+0), SIRS (+1), age > 60 (+0), pleural effusion (+0) = 2 → moderate risk.
- CT only if: not improving by day 3–5, or concern for complications (necrosis, pseudocyst, abscess). Do NOT CT on admission -necrosis takes 48–72h to develop.
Complications to watch: Necrotizing pancreatitis (infected necrosis → antibiotics + drainage), pseudocyst (>4 weeks), pancreatic abscess. Infected necrosis = carbapenems + IR/surgical drainage.
🧪 Workup
Workup
- Lipase >3× ULN
- BMP, CBC, LFTs, Ca²⁺
- RUQ US -ALL patients
- Triglycerides
- CRP at 48h
- MRCP if CBD dilated
- CT at 72h+ only if worsening
💊 Medications
Medications
| Drug | Dose | Route | Notes |
|---|---|---|---|
| LR | 1.5mL/kg/hr | IV | Goal-directed hydration |
| Hydromorphone | 0.5-1mg q3-4h | IV | Multimodal pain |
| Ketorolac | 15-30mg q6h×5d | IV | NSAID adjunct |
| No prophylactic abx | - | - | Unless infected necrosis |
📋 On Rounds
Pimp Questions
When do you give antibiotics in acute pancreatitis?
Only for infected necrosis. Prophylactic antibiotics for necrotizing pancreatitis showed no benefit in multiple RCTs. Sterile necrosis is managed supportively. Suspect infection if: worsening at > 7–10 days, new fever/leukocytosis, gas in necrotic collection on CT. Confirm with FNA. Treat with meropenem (best penetration into pancreatic tissue).
Why LR over NS for pancreatitis resuscitation?
de-Madaria, 2018: LR reduced SIRS at 48h compared to NS. The mechanism: NS causes hyperchloremic metabolic acidosis (high chloride load), which may worsen pancreatic inflammation. LR is more physiologic (contains lactate buffer, less chloride). This is consistent with broader critical care data favoring balanced crystalloids SMART, 2018.
A patient has pancreatitis with TG level of 2,800 mg/dL. How does this change management?
Hypertriglyceridemia-induced pancreatitis (TG typically > 1,000 mg/dL). Management additions beyond standard care: (1) Insulin drip (regular insulin 0.1-0.3 units/kg/hr) -insulin activates lipoprotein lipase → rapidly clears triglycerides. Target TG < 500. Add dextrose to prevent hypoglycemia. (2) NPO strictly until TG < 500 (dietary fat would raise TG further). (3) Fibrate therapy (fenofibrate or gemfibrozil)
When do you order MRCP vs ERCP in gallstone pancreatitis?
MRCP (magnetic resonance cholangiopancreatography): non-invasive imaging to evaluate the common bile duct for stones. Order when: labs suggest choledocholithiasis (elevated bilirubin, dilated CBD on US) but patient is stable and not cholangitic. MRCP visualizes stones without procedural risk. If MRCP shows CBD stone → ERCP for stone removal. If MRCP negative → cholecystectomy without ERCP.
Clinical Examples
📋 Case 1, Gallstone Pancreatitis with Cholangitis
Patient: 52 y/o F with cholelithiasis, presents with severe epigastric pain radiating to the back, fever 39.4°C, and jaundice.
Key findings: HR 118, BP 96/58. Lipase 5,200, total bilirubin 6.8, direct 5.2, ALP 420, WBC 19K. RUQ US: gallstones, CBD dilated to 11 mm.
Management:
- Charcot's triad present (fever + jaundice + RUQ pain), emergent ERCP within 24h (do not wait for MRCP)
- IV antibiotics: pip-tazo 4.5g q6h (biliary source with sepsis)
- Moderate, goal-directed IVF with LR at 1.5 mL/kg/hr (bolus 10 mL/kg only if hypovolemic), titrated to UOP ≥ 0.5 mL/kg/hr. Do NOT run 3 mL/kg/hr: that was the aggressive arm WATERFALL stopped early for harm (fluid overload 20.5% vs 6.3%) with no benefit WATERFALL, 2022
- Cholecystectomy this admission once inflammation resolves
Teaching point: Cholangitis requires urgent ERCP (within 24h), do not waste time with MRCP when Charcot's triad is present. Use MRCP only when choledocholithiasis is suspected but the patient is stable and not cholangitic.
📋 Case 2, Hypertriglyceridemia-Induced Pancreatitis
Patient: 38 y/o M with poorly controlled DM2 and obesity, presents with severe epigastric pain. No alcohol use, no gallstones.
Key findings: Lipase 3,800, triglycerides 4,200 mg/dL, glucose 380, HbA1c 12.4%. Lipemic serum. CT: peripancreatic stranding without necrosis.
Management:
- Insulin drip 0.1-0.3 units/kg/hr, activates lipoprotein lipase to clear TGs rapidly
- Add D5 to prevent hypoglycemia during insulin infusion
- Strict NPO until TG < 500 (dietary fat raises TG further)
- Long-term: fenofibrate, very low-fat diet (< 20g/day), glycemic control
Teaching point: TG-induced pancreatitis (TG > 1,000) requires insulin drip for rapid TG clearance. Unlike gallstone pancreatitis, keep strictly NPO until TGs are controlled. Consider plasmapheresis if TG > 5,000 or refractory to insulin.
📋 Case 3, Necrotizing Pancreatitis with Infected Necrosis
Patient: 60 y/o M with alcohol-induced pancreatitis, initially improving then develops new fever and leukocytosis at day 10.
Key findings: CT abdomen: 40% pancreatic necrosis with gas bubbles in the necrotic collection. WBC 24K (was trending down), fever 38.8°C, procalcitonin rising.
Management:
- Gas in necrotic collection = infected necrosis until proven otherwise
- Meropenem 1g IV q8h (best pancreatic tissue penetration of any antibiotic)
- CT-guided FNA of collection for culture confirmation
- Interventional radiology for percutaneous drain; step-up approach preferred over early surgical necrosectomy PANTER, 2010
Teaching point: Prophylactic antibiotics for sterile necrotizing pancreatitis have no benefit. Antibiotics are indicated ONLY for infected necrosis (suspect at day 7-10+ if clinical worsening). The step-up approach (drain first, surgery only if needed) is superior to early surgery.
📣 Sample Presentation
One-Liner
"Mrs. Garcia is a 45-year-old presenting with severe epigastric pain radiating to the back × 12 hours after a fatty meal. Lipase 4,200. RUQ US shows gallstones with CBD dilation to 8 mm. BISAP score 1."
Key Points to Cover on Rounds
Acute gallstone pancreatitis. Lipase 4,200 (>3× ULN). BISAP 1 (low severity). Treatment: moderate goal-directed IVF with LR (1.5 mL/kg/hr, bolus only if hypovolemic), pain control with hydromorphone 0.5 mg IV PRN. Diet: early oral feeding initiated (clear liquids, advancing as tolerated -don't keep NPO). RUQ US: gallstones, CBD 8 mm → MRCP ordered to evaluate for choledocholithiasis. If CBD stone confirmed → ERCP before cholecystectomy. Surgery consulted for cholecystectomy this admission. CRP trending for severity.
- Lipase trend
- BMP q12-24h
- Ca²⁺ -hypoCa=severe
- UOP
- Oral intake tolerance
- CRP 48h
⚡ Summary
Summary
Diagnose on Two of Three
Characteristic epigastric pain radiating to the back, lipase or amylase at least 3 times the upper limit, or characteristic imaging. Lipase level does not correlate with severity, so a very high value in a well patient is not a reason for the ICU, and a modest rise in a sick one is not reassurance.
Do Not CT on Admission
CT is normal in 15 to 30% of early pancreatitis, because necrosis takes 72 h or more to declare itself. Reserve it for diagnostic uncertainty, no improvement at 48 to 72 h, or suspected complications. An early scan gives a falsely reassuring picture and contributes nothing to management.
I GET SMASHED, but Really Two Causes
Gallstones and alcohol account for roughly 70 to 80%. The rest: hypertriglyceridemia (above 1,000 mg/dL), hypercalcemia, ERCP, trauma, drugs, autoimmune, scorpion sting, mumps. Get a right upper quadrant ultrasound in everyone, and check triglycerides and calcium when the ultrasound is clean, since both are treatable at the cause.
Fluids, Analgesia, Early Feeding
Moderately aggressive lactated Ringer, preferred over normal saline, titrated to perfusion rather than to a fixed volume, since over-resuscitation causes its own harm including abdominal compartment syndrome. Treat pain properly; opioids do not worsen pancreatitis. Feed within 24 h as tolerated, going straight to a low-fat solid diet rather than up a liquid ladder.
No Prophylactic Antibiotics
They do not prevent infected necrosis and they select resistant organisms and fungi. Treat only proven or strongly suspected infection, and suspect infected necrosis when a patient deteriorates after 7 to 10 days, with gas in the collection on CT the specific sign.
Grade Severity Early and Reassess
Revised Atlanta: mild (no organ failure, no complications), moderately severe (transient organ failure under 48 h or local complications), severe (persistent organ failure beyond 48 h). Persistent organ failure is what drives mortality, which reaches 15 to 30% in severe disease, so the 48-hour reassessment matters more than the admission score.
Know the Collections and When to Touch Them
Acute peripancreatic fluid collection and acute necrotic collection in the first 4 weeks; pseudocyst and walled-off necrosis after 4 weeks. Drain for infection, obstruction or refractory symptoms, not for size alone: the old rule of draining any pseudocyst above 6 cm is obsolete. Delay intervention until the collection is walled off, and use a step-up approach of percutaneous or endoscopic drainage before surgical necrosectomy (PANTER, POINTER).
Prevent the Next Episode Before Discharge
Gallstone pancreatitis needs cholecystectomy during the same admission, since recurrence without it is 25 to 30%. Alcohol-related disease needs a cessation intervention started in hospital. Hypertriglyceridemic disease needs a fibrate and dietary management, plus insulin or apheresis acutely. Also watch for the systemic complications: ARDS, acute kidney injury, DIC and abdominal compartment syndrome.
📄 One Pager
Text version
GI · One Pager
Acute Pancreatitis
2 of 3: epigastric pain + lipase > 3× + imaging findings. Moderate goal-directed IVF (1.5 mL/kg/hr LR) + pain control + early feeding. No prophylactic antibiotics. Cholecystectomy this admission if gallstone.
Diagnosis
2 of 3: (1) characteristic epigastric pain radiating to back, (2) lipase > 3× ULN, (3) imaging findings. Lipase preferred over amylase (more specific).
Management
Moderate goal-directed IVF (LR, 1.5 mL/kg/hr). Pain control (multimodal). Early oral feeding as tolerated (don't keep NPO). No prophylactic antibiotics. Monitor for organ failure.
Etiology Workup
Gallstones (#1): RUQ US + LFTs. Alcohol (#2). TG > 1000: insulin drip + fibrates. If unclear: MRCP, IgG4 (autoimmune), genetic testing. ERCP only if cholangitis.
Key Drugs
LR250-500 mL/hr initially
Hydromorphone0.5-1 mg IV PRN
APAP/ketorolacMultimodal adjuncts
Insulin dripIf TG-induced
Pitfalls
- Keeping patient NPO (early feeding is safe + beneficial)
- Prophylactic antibiotics (no benefit, promotes resistance)
- Missing gallstone as cause (US + LFTs in all patients)
- Not doing cholecystectomy this admission for gallstone pancreatitis
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