Gastroenterology · General Medicine

Acute Pancreatitis

Also known as Acute pancreatitis · Haemorrhagic pancreatitis · Necrotising pancreatitis · Gallstone pancreatitis · Alcoholic pancreatitis

Acute pancreatitis is an acute inflammatory process of the pancreas caused by premature intracellular activation of trypsinogen to trypsin within pancreatic acinar cells, with autodigestion of the gland and a systemic inflammatory response. Diagnosed when 2 of 3 criteria are met: characteristic epigastric pain radiating to the back, serum lipase or amylase over 3 times the upper limit of normal, or characteristic imaging (CT/MRI). Gallstones and alcohol together cause about 80 percent of episodes; hypertriglyceridaemia is a third leading cause in some regions. Remember I GET SMASHED for the full list. Severity is graded by the Revised Atlanta classification into mild (no organ failure, no complications — the most common form), moderately severe (transient organ failure under 48 h, or local complications), and severe (persistent organ failure over 48 h). Manage with goal-directed moderate lactated Ringer's (WATERFALL — aggressive fluids harm), adequate IV opioid analgesia, early enteral feeding within 24 to 48 h (no prolonged nil by mouth), no routine prophylactic antibiotics, ERCP within 24 h only for cholangitis or persistent obstruction, and a step-up drainage approach at ~4 weeks for infected necrosis.

High yieldHigh evidenceUpdated 4 Sept 202622 min readVerification in progress

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Red flags

  • Severe constant epigastric pain radiating straight through to the back with vomiting and lipase or amylase over 3 times the upper limit of normal - acute pancreatitis; admit, IV fluids, analgesia
  • Persistent organ failure lasting over 48 h (respiratory, renal, or cardiovascular) - severe pancreatitis (Revised Atlanta); ICU
  • Periumbilical bruising (Cullen's sign) or flank bruising (Grey-Turner's sign) - severe necrotising or haemorrhagic pancreatitis; high mortality
  • Confusion, hypoxia, hypotension, RR over 30, oliguria - SIRS with developing organ failure; ICU and moderate goal-directed lactated Ringer's (WATERFALL)
  • Fever with raised inflammatory markers and gas within pancreatic necrosis on CT, or positive Gram stain on fine-needle aspiration - infected necrosis; carbapenem and drainage
  • Severe epigastric pain with free intraperitoneal gas, peritonism, lactic acidosis, or a pulsatile abdominal mass - exclude perforated peptic ulcer, mesenteric ischaemia and leaking abdominal aortic aneurysm (all can raise amylase)

Meet the patient

A 52-year-old woman arrives at 2am with severe, constant epigastric pain that bores straight through to her back. She has vomited three times, cannot get comfortable lying flat, and is leaning forward in the chair. Her lipase is over three times the upper limit of normal. The ultrasound already ordered shows gallstones.[9]

Three questions decide her next 48 hours, and they are the three that decide every pancreatitis case: is this really pancreatitis?, how severe will it get?, and am I about to make it worse with the fluids? Hold those three and the whole topic falls into place.[1]

Two of three — the diagnosis that needs no scan

You do not need a CT to make this diagnosis. The 2012 Revised Atlanta classification grades severity; diagnosis is the two-of-three rule (pain, enzymes, imaging) used across guidelines — clinical symptoms, raised lipase or amylase, and/or characteristic imaging:[1][11]

  1. Characteristic pain — acute onset of severe, constant epigastric pain, frequently radiating straight through to the back, often eased by sitting forward.
  2. Lipase or amylase over three times the upper limit of normal — and lipase is the preferred enzyme: current diagnostic strategies favour serum lipase over amylase for higher sensitivity and specificity, and lipase has a longer half-life, which helps late presentations.
  3. Characteristic imaging on contrast-enhanced CT, MRI, or ultrasound.[1][18]

When the clinical picture and the enzymes agree, imaging is not required to confirm the diagnosis — ordering a scan delays fluids and adds nothing. The corollary is the trap that costs marks: a normal amylase does not exclude pancreatitis. It falls in hypertriglyceridaemic pancreatitis (lipaemic serum fouls the assay) and in late presentations after the enzyme has already cleared. Reach for lipase first.[9]

The number rule: 2-of-3. Two of three makes the diagnosis; one of three forces you to image. Say it once in the viva and the criteria marks are banked.[1]

Etymology for viva gold: pancreas is Greek pan-kreas, "all flesh" — the ancients noted a gland that was almost entirely digestive tissue with no obvious mechanical job. Trypsin is from Greek tryein, "to wear away" — which is precisely what it does to the gland when it fires early.[1]

I GET SMASHED — and the two that own about 80 percent

Gallstones and alcohol together cause about 80 percent of pancreatitis. Name them first, every time, then recite the rest. The mnemonic every final-prof candidate is expected to reproduce is I GET SMASHED.[11]

  • Gallstones — the commonest single cause: 220 of 391 episodes (56 percent) in a large prospective series, versus 62 (16 percent) for alcohol. Biliary patients were significantly more often female and older, with higher transaminase, alkaline phosphatase and bilirubin at admission.[10]
  • Alcohol — the other half of the pair: gallstones and alcohol abuse together account for about 80 percent of episodes, so take a structured alcohol history in every attack — it changes counselling and recurrence prevention.[11]

The remaining causes live in the mnemonic, and each carries an exam hook:[3]

LetterCauseThe detail examiners probe
IIdiopathicAround 10 to 15 percent — only after thorough exclusion; consider occult microlithiasis, sphincter of Oddi dysfunction, genetics (PRSS1, SPINK1, CFTR)
GGallstonesThe commonest cause
EEthanolSecond commonest
TTraumaBlunt abdominal, post-operative, post-ERCP
SSteroids or SmokingSmoking is now an independent risk factor
MMumps or MalignancyCoxsackie, CMV, Mycoplasma; pancreatic or ampullary cancer
AAutoimmuneIgG4-related type 1 and type 2; steroid-responsive
SScorpion stingTityus trinitatis in the Caribbean
HHypercalcaemia or HypertriglyceridaemiaHypertriglyceridaemia is a leading cause in some regions; measure triglycerides before labelling an attack idiopathic
EERCPAbout 10 percent risk; preventable
DDrugsAzathioprine, didanosine, thiazides, valproate, mesalazine, oestrogens, tetracyclines, GLP-1 agonists
[18] [3]

Drug-induced pancreatitis is a diagnosis of exclusion. The drug must be temporally related, other causes excluded, and the pancreatitis resolves on withdrawal (and recurs on rechallenge in classical cases). The highest-risk drugs are azathioprine and 6-mercaptopurine, didanosine, thiazides, sodium valproate, mesalazine, oestrogens, tetracyclines, and — increasingly flagged — the GLP-1 receptor agonists.[3]

A metabolic cause worth flagging. Hypertriglyceridaemia is now recognised as one of the three commonest causes of acute pancreatitis — alongside gallstone disease and alcohol abuse — and the relative frequency of the three varies by region. Approximately 15 to 20 percent of patients with severe hypertriglyceridaemia (triglycerides over 1000 mg/dL) develop acute pancreatitis. When triglycerides exceed 11.3 mmol/L the risk is about 5 percent; above 22.6 mmol/L it rises to 10 to 20 percent. Prevalence has risen with changing diet, obesity, alcohol consumption and concomitant diabetes mellitus, so measure triglycerides before labelling an attack idiopathic.[18][13]

Trypsin switched on inside the cell — the mechanism in one chain

The single sentence that earns the mechanism marks: acute pancreatitis begins when trypsinogen is activated to trypsin inside the pancreatic acinar cell — before it ever reaches the duodenal lumen where activation is meant to happen — and the gland digests itself.[9]

Normally several brakes keep trypsin silent inside the pancreas, and pancreatitis is what happens when they fail:[1]

  • Trypsinogen is meant to be activated in the duodenal lumen by enterokinase on the brush border — never inside the gland.
  • Inside the acinar cell it is held inactive by the trypsinogen-activation peptide, SPINK1, and chymotrypsin C-mediated degradation.
  • Abnormal sustained calcium signals — from bile acids, alcohol metabolites, or hypercalcaemia — switch trypsinogen on inside the cell and divert secretion to the basolateral membrane into the interstitium.
  • Failure of SPINK1 (genetic) or of lysosomal degradation lets trypsin persist and fire the rest of the zymogen cascade.[1]

Once trypsin lights the zymogen cascade, autodigestion follows along a chain you can recite — and each enzyme explains a complication:[9]

  • Elastase digests the elastic lamina of vessels — the basis of haemorrhagic, necrotising pancreatitis.
  • Phospholipase A2 digests cell-membrane phospholipids — acinar necrosis, and in the lungs surfactant destruction driving ARDS.
  • Lipase digests peripancreatic fat; free fatty acids bind calcium into soaps — the hypocalcaemia of severe disease.
  • Kallikrein and bradykinin drive vasodilation and capillary leak — the third-space loss behind shock.[1]

The systemic cascade is the bridge to organ failure. Injured acinar cells release DAMPs and cytokines — IL-6, IL-8, TNF-alpha, IL-1 beta — producing SIRS, which drives capillary leak (the intravascular hypovolaemia behind shock, and the fluid overload that follows over-resuscitation), ARDS, AKI, and DIC.[9]

Why gallstones do it: most people share a common channel at the ampulla where the bile duct and pancreatic duct join. A migrating stone transiently obstructs the pancreatic duct, raising pressure and sometimes refluxing bile into it — either way, premature trypsinogen activation. Persistent obstruction, in contrast, causes obstructive jaundice and ascending cholangitis — the indications for urgent ERCP.[9]

Why alcohol does it: direct acinar toxicity (fatty acid ethyl esters), protein-plug precipitation that blocks small ductules, and sphincter of Oddi spasm. Chronic exposure builds chronic pancreatitis; an acute flare rides on top.[9]

The numbers that define the disease

2 of 3Symptoms, enzymes, imagingthe diagnostic set
80%Gallstones or alcoholthe dominant causes
1 in 5Develop complicationsnecrosis and/or organ failure
48 hPersistent organ failure = severeRevised Atlanta
2 phasesEarly and lateRevised Atlanta
[11] [3] [1]
FigureCentral mechanism: trypsinogen is prematurely activated to trypsin INSIDE the acinar cell (failure of SPINK1, abnormal calcium signalling). Trypsin activates the zymogen cascade: elastase (vessel wall, haemorrhage), phospholipase A2 (membrane and lung surfactant, necrosis and ARDS), lipase (fat necrosis with calcium soap formation — hypocalcaemia), kallikrein-kinin (vasodilation, third-space loss). Cytokine release produces SIRS and multi-organ failure. (AI-generated educational figure.)

The severity fork — mild, in the middle, or killing them

The morphological split and the severity split are two different axes — do not blur them. Morphology is what the CT shows; severity is what the bedside and the scores show. The Revised Atlanta classification defines three severity grades, and reproducing them verbatim is a viva staple:[1]

  • Mild — the most common form — no organ failure, no local or systemic complications. Usually resolves in the first week; discharge with cause-specific prevention.
  • Moderately severe — transient organ failure resolving under 48 hours, OR local or systemic complications without persistent organ failure. Manage on a monitored ward or HDU.
  • Severepersistent organ failure over 48 hours. The Revised Atlanta grades use a Marshall-style assessment of respiratory, cardiovascular, and renal function; organ failure lasting over 48 hours defines severe disease. Overall mortality is about 2 percent, rising to about 30 percent when persistent organ failure is present. Requires ICU.[1][18]

By morphology the split is between interstitial oedematous pancreatitis (the commoner pattern — diffuse gland enlargement, no necrosis, usually mild) and necrotising pancreatitis (non-enhancing tissue on contrast CT; almost one-fifth of patients develop necrosis and/or organ failure). The face-off is the one examiners reach for:[1]

Interstitial oedematous (mild)

  • The commoner morphological pattern
  • Diffuse gland enlargement, NO necrosis on contrast CT
  • Usually mild course; resolves within a week
  • Local complication: acute peripancreatic fluid collection, pseudocyst

Necrotising (severe)

  • Almost one-fifth of patients develop necrosis and/or organ failure
  • Non-enhancing pancreatic or peripancreatic tissue on contrast CT
  • Higher complication rate (infection, haemorrhage)
  • Local complication: acute necrotic collection, walled-off necrosis
  • Higher mortality if infected
[1]

The discriminator line: necrosis equals lack of enhancement on contrast CT — not "a big pancreas". An oedematous gland enhances normally; a necrotic one does not.[1]

FigureREVISED ATLANTA — SEVERITY: mild (no organ failure, no complications), moderately severe (transient organ failure under 48 h, or local or systemic complications), severe (persistent organ failure over 48 h). MORPHOLOGY: interstitial oedematous (no necrosis) vs necrotising (non-enhancing tissue). TIME-BASED LOCAL COMPLICATIONS: in the first 4 weeks and after 4 weeks, classified by content (fluid vs necrosis) and capsule. (AI-generated educational figure.)

Read the pain, then read the severity — the bedside

The classic pain is unmistakable and it teaches the anatomy. Acute onset of severe, constant, deep-seated epigastric pain radiating straight through to the back, eased by sitting forward (the autonomic plexus sits posteriorly) and worsened by lying flat, eating, coughing, and deep inspiration. It reaches maximum intensity within minutes to hours — distinguishing it from the waxing colic of biliary or renal origin. Nausea and vomiting are invariable.[9]

The examination findings track the severity, so grade as you examine.[1]

  • Mild disease — looks unwell but systemically well: low-grade fever under 38.5 degrees, mild tachycardia, mild epigastric tenderness, bowel sounds normal or slightly reduced.
  • Moderate to severe — signs of SIRS: fever over 38 degrees or hypothermia under 36, heart rate over 90, respiratory rate over 20, WBC over 12 or under 4. Hypotension, oliguria, hypoxia, confusion signal developing organ failure.
  • Established severe or haemorrhagic — distended abdomen from ileus and third-space ascites, tender and guarded epigastrium, absent bowel sounds; a palpable epigastric mass later means pseudocyst.[1]

The two eponymous bruising signs are rare but a viva favourite — and specific for severe necrotising or haemorrhagic disease.[9]

  • Grey-Turner's sign — bluish-green or yellowish-brown flank bruising, blood tracking from the retroperitoneum along fascial planes.
  • Cullen's signperiumbilical bruising, blood tracking via the falciform ligament.
  • Less commonly examined: Fox's sign — bruising in the upper thigh along the inguinal ligament.[1]

Atypical presentations are the ones that bite, because they are missed:

  • The elderly present with confusion, falls, hypothermia, or non-specific decline rather than classic pain — lower threshold to image and to admit.
  • Pregnancy (usually third trimester) is mostly gallstone pancreatitis, sometimes hypertriglyceridaemic; it is missed because epigastric pain is blamed on hyperemesis, reflux, or pre-eclampsia.
  • Diabetic ketoacidosis may precipitate pancreatitis and be its consequence — check ketones and a gas in any diabetic with pancreatitis.
  • Hypertriglyceridaemic pancreatitis shows lipaemic milky plasma and eruptive xanthomata; the amylase may be falsely normal.
  • Post-ERCP pancreatitis declares itself as pain, nausea, and a rising amylase within 4 to 24 hours of the procedure.[9][18]

The mimics that also raise amylase — exclude the AAA

Several lethal abdomens can raise the amylase and masquerade as pancreatitis. The differential of severe epigastric pain radiating to the back is the differential of an acute abdomen, and the recurring preventable miss is the leaking abdominal aortic aneurysm.[9]

  • Perforated peptic ulcer — sudden knife-like epigastric pain becoming generalised, peritonism with a rigid board-like abdomen, free intraperitoneal gas under the diaphragm on an erect chest X-ray or CT. Amylase can be mildly raised. Upper-GI surgical emergency.
  • Mesenteric ischaemia or infarctionpain out of proportion to examination in an elderly vasculopath with atrial fibrillation, lactic acidosis, rectal bleeding; pneumatosis or bowel-wall thickening on CT angiography. A raised amylase is common and misleading.
  • Leaking or ruptured abdominal aortic aneurysm — tearing epigastric and back pain, syncope, hypotension, a pulsatile epigastric mass in an elderly male smoker. A raised amylase is well described. A fatal miss.
  • Inferior myocardial infarction — epigastric pain, nausea, diaphoresis, inferior ST elevation, raised troponin. An ECG is mandatory in any adult with acute epigastric pain.
  • Diabetic ketoacidosis — abdominal pain and vomiting with ketotic breath, high-anion-gap acidosis, hyperglycaemia.
  • Acute cholecystitis or biliary colic — right-upper-quadrant pain with a positive Murphy sign, normal or mildly raised lipase; cholangitis adds Charcot's triad of fever, jaundice, and rigors.[1]

The scores that decide the bed — BISAP at the door, Ranson and Glasgow at 48 hours

Severity grading is not a tick-box exercise — it decides ICU versus ward, and it predicts infected necrosis. Begin with ABCDE, run a focused abdominal exam, then deploy the score that fits the clock.[1]

ABCDE — look for the organ failure that defines severe disease:[1]

  • Airway — patent; protect if vomiting with a reduced GCS.
  • Breathing — respiratory rate, SpO2 on air. Hypoxia (SpO2 under 92 percent or PaO2 under 8 kPa) signals respiratory organ failure.
  • Circulation — heart rate, blood pressure, capillary refill, JVP. Systolic under 90 mmHg signals cardiovascular organ failure.
  • Disability — GCS or AVPU; confusion is a marker of severe disease and a Glasgow or BISAP criterion.
  • Exposure — fully expose the abdomen.[1]

Bedside observations that define severity: the Revised Atlanta grades track the organ systems whose failure defines severe disease — respiratory, renal and cardiovascular. Monitor oxygenation, urine output and blood pressure closely through the first days, because failure persisting beyond 48 hours is the definition of severe pancreatitis.[1]

SIRS at the bedside — two or more of temperature over 38 or under 36 degrees, heart rate over 90, respiratory rate over 20, WBC over 12 or under 4. SIRS at admission and at 48 hours predicts severe disease and infected necrosis.[9]

Ranson — the legacy 48-hour score

Ranson's prognostic indicators are collected at admission and over the first 48 hours, and the count grades severity: surgical series took more than 5 Ranson indicators as their threshold for moderate-to-severe disease, and earlier series used such prognostic signs to separate "mild" attacks (1.8 percent mortality) from "severe" ones (17 percent mortality). The score is an exam staple but slow — it cannot be completed at the door, which is why BISAP has largely replaced it for early triage. No score overrides the Revised Atlanta definition: severity is organ failure persisting beyond 48 hours.[19][20][1][4]

BISAP — the one to use at the door

A simple 5-point score computed within the first 24 hours, derived by Wu et al. 2008 from a large US population-based dataset. This is the bedside score that is actually usable at admission:[4]

  • Blood urea nitrogen over 25 mg/dL (8.6 mmol/L)
  • Impaired mental status
  • SIRS
  • Age over 60 years
  • Pleural effusion
  • One point each, within the first 24 hours: in-hospital mortality ranged from over 20 percent in the highest-risk group to under 1 percent in the lowest (BISAP AUC 0.82, APACHE II 0.83 in validation).[4]

APACHE-II and CRP

APACHE-II is the dynamic physiological ICU score — in Wu's validation cohort its accuracy for early mortality was essentially identical to BISAP (AUC 0.83 versus 0.82), but it is complex and time-consuming. CRP at 48 hours adds discriminative value for the CT findings that matter: it predicts pancreatic fluid collections and necrosis on the 72-hour scan.[4][17]

Cross-sectional imaging — when and why

Contrast-enhanced CT is not needed at admission in obvious cases. It is indicated when the diagnosis is uncertain, when severity must be assessed at 48 to 72 hours to detect necrosis (the timing matters — necrosis may not be visible on day one), or when a complication is suspected. The lack of parenchymal enhancement defines necrosis. MRI or MRCP is equivalent for diagnosis and preferred in pregnancy and to characterise the biliary tree non-invasively; EUS hunts occult microlithiasis, sludge, and small tumours in unexplained recurrent disease.[1]

Diagnosing infected necrosis: gas within necrosis on CT is highly suggestive; a positive Gram stain or culture on image-guided fine-needle aspiration is confirmatory. Reserve FNA for the clinically deteriorating patient in whom infection is suspected but unproven.[5]

I GET SMASHED

  • IIdiopathic (around 10 to 15%)
  • GGallstones (commonest; with alcohol ~80%)
  • EEthanol (with gallstones ~80%)
  • TTrauma (blunt, post-op, ERCP)
  • SSteroids or Smoking
  • MMumps or Malignancy
  • AAutoimmune (IgG4)
  • SScorpion sting
  • HHypercalcaemia or Hypertriglyceridaemia
  • EERCP (about 10%)
  • DDrugs (azathioprine, thiazides, valproate, GLP-1)
[18] [11]

Three dogmas overturned — the modern management

FigureManagement ladder — (1) goal-directed moderate lactated Ringer's (avoid aggressive — WATERFALL). (2) Adequate IV opioid analgesia. (3) Early enteral feeding within 24 to 48 h (no prolonged NPO). (4) No routine prophylactic antibiotics — only for infected necrosis (carbapenem) or cholangitis. (5) ERCP within 24 h only for cholangitis or persistent biliary obstruction. (6) Same-admission cholecystectomy in mild gallstone disease. (7) Step-up drainage at around 4 weeks for infected necrosis. (AI-generated educational figure.)

Admit everyone; severe disease goes to ICU or HDU. Run ABCDE — high-flow oxygen to target SpO2 94 to 98 percent (88 to 92 percent in a chronic CO2 retainer), two large-bore cannulae, a urinary catheter for hourly output, reliable IV access.[3]

The single most important early intervention is goal-directed fluid resuscitation — and the single most important lesson is that aggressive fluids harm.[2]

Goal-directed moderate lactated Ringer's (WATERFALL)

  1. 1

    Crystalloid: lactated Ringer's

    Both arms of WATERFALL used goal-directed lactated Ringer's — the resuscitation strategy, not the fluid type, drove the safety difference

  2. 2

    Moderate resuscitation

    A 10 mL/kg bolus only in hypovolaemia (no bolus if normovolaemic), then 1.5 mL/kg per hour

  3. 3

    Scheduled reassessment

    Patients were assessed at 12, 24, 48 and 72 hours and resuscitation adjusted to clinical status

  4. 4

    Avoid the aggressive regimen

    20 mL/kg bolus then 3 mL/kg per hour caused fluid overload in 20.5% versus 6.3% (adjusted relative risk 2.85)

[2]

Escalate to ICU or HDU the moment organ failure develops or persists — persistent hypoxia, hypotension unresponsive to fluids, oliguria not responding to a fluid challenge, confusion. That persistence is the definition of severe pancreatitis.[1]

Feed the gut, withhold the antibiotic, time the ERCP

Early enteral feeding within 24 to 48 hours is the standard of care — and it overturned the old nil-by-mouth dogma.[3]

  • In mild pancreatitis, start a low-fat solid or liquid diet orally within 24 to 48 hours and advance as tolerated.
  • In severe disease or gastric intolerance, nasogastric feeding is as effective as nasojejunal in most trials — reserve NJ for those who fail NG.
  • Total parenteral nutrition is reserved for prolonged ileus, fistula, or enteral failure — it does not improve outcome and increases infection.[1]

Antibiotics are the most important "less is more" lesson in the topic. Routine prophylactic antibiotics do not reduce infected necrosis or mortality — and they cause harm: resistant organisms, fungal overgrowth, and Clostridioides difficile. Do not give them. This is a meta-analysis-level conclusion.[7]

Give antibiotics only when:[7]

  1. Infected necrosis — proven by gas in necrosis on CT or positive FNA, OR strongly suspected by clinical deterioration with raised inflammatory markers.
  2. Acute cholangitis (fever, jaundice, rigors, abdominal pain — Charcot's triad) with biliary obstruction.
  3. An extrapancreatic infection — pneumonia, UTI, bacteraemia.[7]

Infected necrosis is treated with antibiotics plus source control. Infected pancreatic necrosis requires debridement and drainage supplemented by antibiotic therapy, whereas sterile necrosis is managed conservatively — and computed-tomography-guided fine-needle aspiration is the technique of choice to tell them apart.[11][1]

ERCP is early, but only for specific indications — and routine ERCP without obstruction is the recurring trainee error:[8]

  • Within 24 hours for acute cholangitis and persistent biliary obstruction (jaundice, dilated CBD with a stone, or worsening LFTs).
  • NOT routinely in gallstone pancreatitis without obstruction — the Cochrane review (Tse and Yuan 2012) showed no benefit and a trend to harm in this group.[8]

Cholecystectomy, hypertriglyceridaemia, and the step-up for necrosis

Same-admission cholecystectomy in mild gallstone pancreatitis is non-negotiable — ACG 2024 states that biliary pancreatitis typically requires surgery to prevent recurrent disease, and in Ranson's series 7 of 21 patients (33 percent) discharged without a biliary operation developed further pancreatitis.[3][20]

  • Mild gallstone pancreatitis — same-admission laparoscopic cholecystectomy after symptoms settle, before discharge.
  • Severe pancreatitis (necrosis, organ failure) — delay cholecystectomy until complete resolution, sometimes staged after recovery from necrosectomy.
  • Unfit for surgery — ERCP plus sphincterotomy before discharge defunctions the sphincter and reduces recurrence as a second-line approach.[1]

Hypertriglyceridaemic pancreatitis needs cause-specific therapy. Cause-defining thresholds sit in the cause section (over 1000 mg/dL or 11.3 mmol/L). Specific treatment beyond standard pancreatitis care is insulin, heparin and lipid-lowering drugs; insulin therapy with close blood-glucose monitoring is safe and effective even where plasmapheresis is unavailable, and therapeutic plasmapheresis is the most effective option in severe disease, removing triglycerides and pro-inflammatory cytokines.[18][13][12]

Autoimmune pancreatitis responds to steroids — but relapse is the rule. Type 1 is the pancreatic manifestation of IgG4-related disease and is steroid-responsive: all 138 patients in a long-term cohort entered remission with initial steroid therapy, yet 47.8 percent relapsed (about three-quarters within 3 years), and long-term pancreatic insufficiency and stone formation are common.[15][14]

The step-up approach for infected necrosis is the modern standard — open necrosectomy is now the last resort. The PANTER and TENSION trials established it:[5]

  • Delay intervention around 4 weeks if possible — it lets the collection wall off and become drainable, reducing bleeding and organ failure.
  • Step 1: percutaneous or endoscopic (EUS-guided) catheter drainage — controls sepsis in most.
  • Step 2: if drainage fails, endoscopic or minimally invasive necrosectomy — PANTER showed step-up versus open necrosectomy reduced the composite of major complications or death (40 versus 69 percent), with 35 percent needing drainage alone and less new-onset multiple-organ failure (12 versus 40 percent). ExTENSION (long-term TENSION) did not show a difference in death or major complications at 7 years (53 versus 57 percent) but found fewer fistulas and fewer late reinterventions with the endoscopic route.[5][6]

The complications clock — by content and by timing

Local complications are classified by content (fluid versus necrosis) and by timing (under or over 4 weeks) — reproduce the four-box table.[1]

CollectionTimingContentCapsule
Acute peripancreatic fluid collection (APFC)first 4 weeksfluid, no necrosisnone
Pancreatic pseudocystafter 4 weeksfluid, no necrosisencapsulated
Acute necrotic collection (ANC)first 4 weeksnecrosis plus fluidnone
Walled-off necrosis (WON)after 4 weeksnecrosis plus fluidencapsulated
[1]

A pseudocyst is a fluid collection encapsulated by a non-epithelial fibrous wall, without necrosis, persisting over 4 weeks — drain (endoscopic or surgical) only if symptomatic or infected, not by a size or calendar cut-off alone.[1]

Other local complications, each with a one-line teaching point:[1]

  • Infected necrosis — the leading cause of late death; diagnose by gas in necrosis on CT or positive FNA; treat with carbapenem plus step-up drainage.
  • Haemorrhage — erosion into splenic, gastroduodenal, or pancreaticoduodenal arteries; diagnose by CT angiography, treat by interventional radiology embolisation.
  • Splenic and portal vein thrombosis — splenic vein thrombosis may cause gastric varices with a bleed risk.
  • Gastric outlet or duodenal obstruction — compression by a phlegmon or walled-off necrosis.[5]

Systemic complications track the cytokine cascade: SIRS and sepsis, organ failure (ARDS from phospholipase A2 destroying surfactant, AKI, shock, DIC), metabolic derangement (hypocalcaemia from saponification, hyperglycaemia or diabetes from endocrine loss, hypomagnesaemia), and stress ulceration with DVT or PE risk — prophylactic LMWH once bleeding risk is controlled.[9]

Long-term, watch for the insufficiencies: exocrine failure (steatorrhoea, weight loss — pancreatic enzyme replacement) and endocrine failure (type 3c diabetes), recurrent pancreatitis, and progression to chronic pancreatitis.[1]

How pancreatitis patients come to harm — the preventable list

  • A leaking AAA labelled pancreatitis because the amylase was mildly raised — the preventable death.[9]
  • Aggressive fluids chasing a falling haematocrit into pulmonary oedema and abdominal compartment syndrome (WATERFALL).[2]
  • Prolonged nil by mouth starving the gut into bacterial translocation and infected necrosis.[3]
  • Routine prophylactic antibiotics breeding resistance, fungi, and C. difficile with no benefit.[7]
  • Early open necrosectomy on day three, before the collection walls off — high mortality.[5]
  • Routine ERCP without obstruction, causing more ERCP-related pancreatitis and cholangitis.[8]
  • Forgetting same-admission cholecystectomy in mild gallstone pancreatitis — further pancreatitis in a third of patients discharged without a biliary operation in Ranson's series.[20]
  • Over-relying on amylase, missing the hypertriglyceridaemic or late-presenting case where it is normal.[9]

The trials that overturned the dogma

WATERFALL (de-Madaria et al., NEJM 2022)

Population: 249 patients with acute pancreatitis (interim analysis; trial stopped early for safety)

Key finding

Fluid overload developed in 20.5% versus 6.3% (adjusted relative risk 2.85); moderately severe or severe pancreatitis occurred in 22.1% versus 17.3% (not significant).

[2]

PANTER (van Santvoort et al., NEJM 2010)

Population: Patients with necrotising pancreatitis

Key finding

Step-up reduced the primary composite of major complications or death (40 versus 69 percent); 35 percent needed drainage alone; new-onset multiple-organ failure 12 versus 40 percent.

[5]

ExTENSION (Onnekink et al., Gastroenterology 2022) — long-term TENSION follow-up

Population: 83 of 98 TENSION patients alive after 6 months, mean 7-year follow-up

Key finding

Death or major complications 53% versus 57% (not significant). Fewer pancreaticocutaneous fistulas (8% versus 34%) and fewer reinterventions after 6 months (7% versus 24%). Pancreatic insufficiency and quality of life did not differ.

[6]

Wu 2011 (Clin Gastroenterol Hepatol)

Population: 40 patients with acute pancreatitis randomised to goal-directed or standard resuscitation with lactated Ringer's or saline

Key finding

Lactated Ringer's reduced SIRS after 24 hours (84% reduction versus 0%) and CRP (51.5 versus 104 mg/dL). Goal-directed volume targeting did not reduce SIRS versus standard volumes (11.8 versus 13.0 percent).

[21]

The antibiotic question is settled at the meta-analysis level. Poropat and colleagues' 2022 systematic review with trial sequential analysis confirmed that prophylactic antibiotics do not reduce infected necrosis or mortality — the modern guideline position.[7]

India — practice points

The commonest causes of acute pancreatitis — gallstone disease, hypertriglyceridaemia and alcohol abuse — vary by region, so the local cause mix should shape the first-line work-up. Tropical calcific pancreatitis (TCP) is a distinct chronic non-alcoholic pancreatitis first reported in the developing tropical world: expect pancreatic calcification and ductal dilation on imaging, a phenotype now seen in relatively older patients with less severe symptoms than the original 1968 description, and a substantial genetic contribution (SPINK1, cathepsin B, chymotrypsin C, CFTR and carboxypeptidase A1 variants).[18][16]

United Kingdom — NICE and BSG

NICE NG104 (2018) and BSG practice are named here as the UK exam frame; the numbers in this topic are those fetched from WATERFALL, ACG 2024, Poropat, and Tse: goal-directed moderate LR, early refeeding, no routine prophylactic antibiotics, ERCP for cholangitis or obstruction, and surgery to prevent recurrent biliary disease. The UK Sepsis Six applies to any septic patient. NG104 itself was not re-fetched this pass.[2][3][7][8]

Special populations — what changes

Pregnancy. The commonest cause is gallstones, with risk rising in the third trimester (progesterone-driven gallbladder hypomotility) and with hyperemesis-related biliary stasis; hypertriglyceridaemia also rises. Presentation is as the non-pregnant but may be missed — blamed on hyperemesis, reflux, or pre-eclampsia. Safe imaging is ultrasound and MRI or MRCP; avoid CT. Manage as the non-pregnant — moderate goal-directed LR, early enteral feeding, ERCP for cholangitis with foetal shielding and obstetric involvement, same-admission or early postpartum cholecystectomy. Maternal mortality is low; foetal loss rises in severe disease.[3]

The elderly. Atypical and blunted — confusion, falls, hypothermia — with higher comorbidity and higher mortality. Lower threshold for ICU and for cross-sectional imaging. Use NSAID analgesia cautiously (renal and GI bleeding); give DVT prophylaxis.[3]

The alcoholic patient. Alcohol is one of the two dominant causes, and alcohol-related attacks ride on metabolic comorbidity — hypertriglyceridaemia and concomitant diabetes are increasingly prevalent and worsen the picture. Take a structured alcohol history, check triglycerides and glucose, and engage cessation support before discharge.[11][13]

The immunocompromised. Broaden the differential to opportunistic infection (CMV, Mycobacterium avium, invasive fungal) and drug toxicity (didanosine, antiretrovirals). Lower threshold for imaging and microbiological work-up.[3]

Children. Rare — consider trauma (handlebar injury, non-accidental injury), structural disease (pancreas divisum, choledochal cyst, annular pancreas), systemic disease (cystic fibrosis, hypercalcaemia), drugs (valproate, corticosteroids), and infection (mumps). Manage in a specialist paediatric centre.[3]

The mantra, and the mnemonic

The mantra: two of three for the diagnosis, BISAP at the door, moderate Ringer's not a torrent, feed the gut, keep the antibiotic in the drawer — and wait four weeks before you drain.[1][2]

Ward-round test — three stems, thirty seconds each

Stem 1 — the woman from the top of the topic (answer)Show

The 52-year-old with epigastric pain boring to the back, vomiting, lipase over three times the upper limit of normal, and gallstones on ultrasound. What are your first three moves? Model: This is acute pancreatitis by two of three (pain plus enzymes) — no CT needed yet. (1) Admit, ABCDE, secure IV access, and monitor for the organ failure that defines severity — respiratory, renal, cardiovascular. (2) Start goal-directed moderate lactated Ringer's — a 10 mL/kg bolus only if hypovolaemic, then 1.5 mL/kg per hour with scheduled reassessment — not the aggressive 20 mL/kg bolus that WATERFALL showed causes fluid overload. (3) Score BISAP at the door, plan early refeeding, and let the admission liver enzymes point to the cause — a raised ALT predicts gallstones (positive predictive value about 79 percent), so plan cholecystectomy once she settles.[1][2][10]

Stem 2 — the older man with a mildly raised amylase (answer)Show

A 74-year-old male smoker presents with severe epigastric and back pain, syncope, hypotension, and amylase mildly raised. What must you exclude before you accept the pancreatitis label? Model: Exclude a leaking abdominal aortic aneurysm. A pulsatile epigastric mass in an elderly vasculopath with tearing back pain and syncope, plus a mildly raised amylase, is an AAA until proven otherwise — and anticoagulating or fluid-loading the wrong diagnosis is a preventable death. Palpate the aorta, get a CT angiography. Mesenteric ischaemia is the other mimic that raises amylase — look for pain out of proportion and lactic acidosis. The amylase does not make it pancreatitis.[9]

Stem 3 — the necrosis that turns septic at week three (answer)Show

A patient with severe necrotising pancreatitis develops fever, raised inflammatory markers, and gas within the necrosis on CT at day 22. What is the diagnosis, the drug, and the timing of intervention? Model: This is infected necrosis — secondary infection of pancreatic or peripancreatic necrosis is, with organ failure, the key determinant of prognosis. Give antibiotics and achieve source control: the step-up approach — percutaneous or endoscopic catheter drainage first, minimally invasive necrosectomy only if drainage fails — beat primary open necrosectomy in the PANTER trial (composite of major complications or death 40 versus 69 percent; new-onset multiple-organ failure 12 versus 40 percent), and 35 percent needed drainage alone. Open necrosectomy is the last resort; prophylactic antibiotics were never indicated — these are therapeutic, for proven infection.[9][5][6]

References21Show
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  3. [3]Tenner S, Vege SS, Sheth SG, et al. American College of Gastroenterology Guidelines: Management of Acute Pancreatitis Am J Gastroenterol, 2024.PMID 38857482
  4. [4]Wu BU, Johannes RS, Sun X, et al. The early prediction of mortality in acute pancreatitis: a large population-based study Gut, 2008.PMID 18519429
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Acute Pancreatitis · NeetVellum