GI Emergencies in ICU — GI Bleed, Pancreatitis

📘 1 · Washington Manual of Critical Care, 4th Ed

GI Bleed — Classification & Initial Assessment

"Upper gastrointestinal bleeding (UGIB), defined as haemorrhage from a source proximal to the ligament of Treitz, is a common ICU emergency with in-hospital mortality of 2–10%. Immediate priorities include haemodynamic resuscitation, risk stratification using validated scores, and early endoscopy in high-risk cases. Over-transfusion is as dangerous as under-resuscitation — the TRIGGER trial demonstrated that a restrictive haemoglobin transfusion threshold (70–80 g/L) reduces mortality compared to a liberal strategy."

Washington Manual of Critical Care, 4th Ed. Wolters Kluwer 2023. Chapter: Gastrointestinal Haemorrhage.

UGIB Causes (by Frequency)

Peptic ulcer disease (40–50%) — gastric or duodenal ulcer; NSAIDs, H. pylori, stress
Oesophageal/gastric varices (10–20%) — portal hypertension; high rebleed risk; specific management
Mallory-Weiss tear (5–15%) — vomiting-related; usually self-limiting
Erosive gastritis/oesophagitis (5–10%)
Dieulafoy lesion — visible vessel without ulceration; in fundus; difficult to identify endoscopically
Aortoenteric fistula — rare but immediately fatal if missed; consider in any patient with prior aortic surgery + UGIB

Glasgow-Blatchford Score (GBS) — Triage Tool

Blatchford Score Variables & Points

Urea ≥6.5 <8.0 mmol/L+2 Urea ≥8.0 <10.0+3 Urea ≥10.0 <25.0+4 Urea ≥25.0 mmol/L+6 Hb <130 g/L (male) / <120 g/L (female)+1 to +6 SBP 100–109 mmHg+1 SBP 90–99 mmHg+2 SBP <90 mmHg+3 HR ≥100 bpm+1 Melaena present+1 Syncope+2 Hepatic disease present+2 Cardiac failure present+2

Score 0: Very low risk — outpatient management possible | Score ≥1: Hospital admission | Score ≥6: High risk — urgent endoscopy, HDU/ICU

Initial Resuscitation — UGIB

Airway: Active haematemesis with altered consciousness → intubate before endoscopy
2 large-bore (≥16G) peripheral IVs; consider CVC if peripheral access poor
Transfusion threshold: Hb <70 g/L (restrictive strategy — TRIGGER trial) — target Hb 70–90 g/L. Exception: ACS or haemodynamic instability → transfuse to Hb 80–100 g/L
Variceal bleed: Hb target 70–80 g/L — over-transfusion raises portal pressure and increases rebleed risk
Coagulopathy correction: FFP if INR >1.5 and active bleeding; platelets if <50 × 10⁹/L and active bleed
Antibiotics: ALL variceal UGIB patients need prophylactic antibiotics (ceftriaxone 1g IV 24h → ciprofloxacin 400 mg BD for 7 days) — reduces spontaneous bacterial peritonitis and mortality

📗 2 · Marino's The ICU Book, 5th Edition (2025)

Acute Pancreatitis — Pathophysiology

"Acute pancreatitis is an inflammatory condition of the pancreas that can range from mild self-limited disease to a life-threatening multi-organ failure syndrome. The inciting event — whether gallstone, alcohol, or other cause — triggers premature intrapancreatic activation of digestive enzymes, leading to autodigestion of pancreatic and peripancreatic tissue. The subsequent inflammatory cascade, particularly in severe disease, extends far beyond the pancreas and drives a SIRS-like systemic response indistinguishable from septic shock."

Marino PL. The ICU Book, 5th Ed. GI Failure. Wolters Kluwer; 2025.

📗 Marino — Pathophysiology Cascade

In normal physiology, digestive enzymes are synthesised as inactive zymogens (trypsinogen, chymotrypsinogen) and activated only in the duodenum. In pancreatitis:

Trigger (gallstone obstruction, alcohol, hypertriglyceridaemia, ERCP) → trypsinogen activation within pancreatic acinar cells
Active trypsin activates all other zymogens → autodigestion of pancreatic parenchyma and fat
Phospholipase A₂ → lecithin → lysolecithin → cell membrane disruption → local tissue necrosis
Activated inflammatory cells (macrophages, neutrophils) → cytokine storm (TNF-α, IL-1, IL-6) → SIRS → distant organ injury
Consequence: ARDS (pulmonary), AKI, cardiovascular collapse, coagulopathy (DIC), gut barrier failure

📗 Marino — Revised Atlanta Classification (2012)

Two types of necrosis, two timeframes, three severity grades:

Local complications:

Acute peri-pancreatic fluid collection (APFC): First 4 weeks, no wall, no necrosis — usually resolves spontaneously
Pancreatic pseudocyst: After 4 weeks, well-defined wall, liquid content, no necrosis
Acute necrotic collection (ANC): First 4 weeks, contains necrosis — high infection risk
Walled-off necrosis (WON): After 4 weeks, organised wall around necrotic material — the target for drainage if infected

Infected necrosis: Gas in collection on CT (pathognomonic) or FNA culture-positive. Treatment: antibiotics + endoscopic/surgical step-up necrosectomy.

📗 Marino — Why the Pancreas Must Be Rested... but the Gut Must Be Fed

The old teaching of "pancreatic rest" (nil-by-mouth until amylase normalises) is wrong and harmful. Multiple RCTs confirm:

Early enteral nutrition (within 24–48h) maintains gut mucosal integrity, prevents bacterial translocation, reduces infectious complications
Total parenteral nutrition (TPN) alone increases infectious morbidity, line sepsis, and cost
NG feeding is equivalent to NJ feeding (nasojejunal) — either route is acceptable

The pancreas itself tolerates enteral feeds well — it is the systemic inflammatory response that requires supportive care, not pancreatic rest.

📋 3 · ASGE 2021 (GI Bleed) & ACG 2013 (Pancreatitis)

Evidence-Based Guidelines

UGIB — ASGE 2021 Guidelines

Endoscopy Timing — ASGE 2021

High-risk UGIB (GBS ≥6, haemodynamic instability, active bleeding): Endoscopy within 24h of presentation STRONG — ASGE 2021
Low-risk UGIB (GBS ≤2, no haemodynamic compromise, haematemesis resolved): Endoscopy within 72h — outpatient or next-day elective
Very early endoscopy (<6h) for all UGIB: NOT recommended — no mortality benefit and increases procedure complication rate in unstable patients
Pre-endoscopy PPI infusion: Omeprazole 80 mg IV bolus → 8 mg/h infusion — does NOT prevent rebleed or reduce mortality, but reduces the need for endoscopic intervention (downstages lesions). Still standard practice.

Variceal UGIB — Specific Management

Terlipressin (first-line vasoactive drug): 2 mg IV every 4h for 48h → 1 mg 4-hourly (ongoing) for up to 5 days STRONG
Alternative: Octreotide 50 μg IV bolus → 50 μg/h infusion for 5 days
Endoscopic variceal ligation (EVL) for oesophageal varices — within 12–24h; superior to injection sclerotherapy
TIPSS (Transjugular Intrahepatic Portosystemic Shunt): For refractory variceal bleeding after 2 failed endoscopic attempts — also early TIPSS in Child-Pugh C or high HVPG reduces 6-week mortality STRONG
Sengstaken-Blakemore tube: Temporary tamponade bridge (not definitive) — maximum 24h; use only when all other options fail or as bridge to TIPSS/surgery

Transfusion Strategy — TRIGGER Trial

Restrictive strategy (Hb threshold 70 g/L): Associated with lower 28-day mortality (4.9% vs 11%) compared to liberal strategy (Hb 90 g/L) in acute UGIB STRONG 1A — TRIGGER 2015
Exception: Hb 80–90 g/L threshold for patients with ACS (type 2 MI from blood loss)
FFP: Only for INR >1.5 with active bleeding — not to correct INR prophylactically
Platelets: Transfuse if <50 × 10⁹/L and actively bleeding

Acute Pancreatitis — ACG 2013 Guidelines

Severity Assessment — Revised Atlanta + CTSI

Revised Atlanta Severity:
• Mild: No organ failure, no local complications — 90% of cases, mortality <1%, discharge within 3–5 days
• Moderately severe: Transient organ failure (<48h) OR local complications — mortality ~5%
• Severe: Persistent organ failure (>48h), single or multi-organ — mortality 20–40%

CT Severity Index (CTSI = Balthazar grade + necrosis score): CTSI ≥7 = severe; CT indicated if diagnosis uncertain or no improvement at 48–72h; NOT required routinely in mild disease (radiation without benefit).

Bedside scoring: BISAP score (BUN >25, impaired mental status, SIRS, age >60, pleural effusion) ≥3 = high mortality risk

Fluid Resuscitation — ACG 2013 + Recent Evidence

Lactated Ringer's (LR) preferred over Normal Saline STRONG — ACG 2013 + WATERFALL trial 2022
LR reduces systemic inflammation (Ca²⁺ in LR may inhibit pancreatic trypsin activation; LR has lower chloride — less hyperchloraemic acidosis)
Rate: 250–500 mL/h in first 24–48h; titrate to BUN, HCT, UO (target >0.5 mL/kg/h), clinical assessment
Reassess at 6h: If BUN increasing or HCT rising → more aggressive resuscitation; if HCT falling with adequate UO → adequate resuscitation
Avoid over-resuscitation: WATERFALL trial showed that aggressive (rapid) fluid resuscitation was NOT superior to standard resuscitation and increased fluid overload complications.

Nutrition in Pancreatitis

Mild pancreatitis: Oral low-fat diet as soon as pain allows — NBM not required STRONG — ACG 2013
Severe pancreatitis (predicted): Enteral nutrition within 24–48h via NG or NJ tube STRONG — ESPEN 2020
TPN: Only if EN fails or is contraindicated (fistula, abdominal compartment syndrome) — associated with higher infection and mortality
NG feeding = NJ feeding for tolerability and outcomes — NG is simpler and preferred
Target: 25 kcal/kg/day; protein 1.2–1.5 g/kg/day; semi-elemental formula preferred in severe disease

Antibiotics in Pancreatitis — ACG 2013

NO prophylactic antibiotics in acute pancreatitis — even in severe or necrotising disease STRONG 1A — ACG 2013
Multiple RCTs including Isenmann (2004), Dellinger (2007) show no benefit to prophylactic carbapenems or quinolones in sterile necrosis.
Antibiotics indicated ONLY for:
• Confirmed infected necrosis (gas on CT, positive FNA culture)
• Concurrent cholangitis (biliary sepsis)
• Extra-pancreatic infection (UTI, pneumonia)
Antibiotic choice for infected necrosis: Meropenem 500 mg–1g IV TDS (good pancreatic tissue penetration) OR imipenem-cilastatin. Add antifungal if Candida isolated.

ERCP in Gallstone Pancreatitis

Urgent ERCP (within 24h): Only if concurrent acute cholangitis or persistent biliary obstruction (rising bilirubin, dilated CBD on US) STRONG
No benefit of urgent ERCP in predicted severe gallstone pancreatitis without cholangitis — may worsen outcomes
Cholecystectomy: Perform during same admission for mild gallstone pancreatitis (reduces recurrence risk); delay by 4–6 weeks for severe disease or peripancreatic fluid collections.

🇮🇳 Indian Context

Tropical pancreatitis: Chronic calcific pancreatitis secondary to cassava (tapioca) consumption — endemic in Kerala and other states; typically presents young, recurrent acute-on-chronic episodes. Low serum trypsinogen levels.

Hypertriglyceridaemia-induced pancreatitis: Common in Indian diabetics and metabolic syndrome patients. Triglycerides >11.3 mmol/L (1000 mg/dL). Treatment: insulin infusion (activates lipoprotein lipase) + plasmapheresis if severe. Standard pancreatitis management thereafter.

GI bleed causes in India: Variceal bleeding is more common in Indian ICUs (due to higher prevalence of hepatitis B/C cirrhosis). Always ask about alcohol use and jaundice history in all UGIB presentations.

💊 4 · Drug Doses

Drug Reference — GI Emergencies

Drug	Indication	Dose	Notes
Pantoprazole / Omeprazole IV	UGIB — non-variceal	80 mg IV bolus → 8 mg/h infusion for 72h	Post-endoscopic therapy; also pre-endoscopy to downstage lesion
Terlipressin	Variceal UGIB (first-line)	2 mg IV every 4h × 48h → 1 mg every 4h × 5 days total	Contraindicated: severe IHD, peripheral vascular disease; watch for hypertension & bradycardia
Octreotide	Variceal UGIB (alternative to terlipressin)	50 μg IV bolus → 50 μg/h continuous infusion × 5 days	More widely available in India; equivalent efficacy to terlipressin
Ceftriaxone	Variceal bleed antibiotic prophylaxis	1g IV OD for 5–7 days (preferred in ascites or Child-Pugh C)	Reduces SBP, bacteraemia, and rebleeding rate; reduces mortality in cirrhosis
Norfloxacin	Variceal bleed prophylaxis (if no ascites)	400 mg PO BD for 7 days	Oral alternative to ceftriaxone; inferior in advanced cirrhosis
Lactated Ringer's	Pancreatitis fluid resuscitation	250–500 mL/h initial × 24–48h; titrate to UO >0.5 mL/kg/h	Preferred over NS; reduces systemic inflammation; contains Ca²⁺
Meropenem	Infected pancreatic necrosis	500 mg–1g IV TDS (adjusted for renal function)	Good pancreatic tissue penetration; use only when infected necrosis confirmed
Insulin (regular) IV infusion	Hypertriglyceridaemia-induced pancreatitis	0.1–0.3 U/kg/h; titrate to reduce TG to <5.6 mmol/L	Activates lipoprotein lipase; concurrent dextrose infusion to prevent hypoglycaemia

🗂 5 · Clinical Flowchart

UGIB & Pancreatitis Management Algorithms

UGIB Management Ladder

Resuscitate

2 large-bore IVs, crossmatch, bloods, type and screen
Transfuse to Hb ≥70 g/L (≥80 if ACS)
Airway protection if haematemesis + reduced GCS

Risk Stratify

Calculate Glasgow-Blatchford Score
Is this likely variceal? (chronic liver disease, portal hypertension history)
If variceal: terlipressin + ceftriaxone immediately
If non-variceal: PPI infusion (80 mg → 8 mg/h)

Endoscopy Timing Decision

Unstable / GBS ≥6: OGD within 24h
Stable / GBS <6: OGD within 72h
Variceal: OGD within 12–24h (EVL preferred)
Pre-endoscopy erythromycin 250 mg IV if large haematemesis (clears stomach)

Post-Endoscopy Care

Haemostasis achieved: Oral PPI (omeprazole 40 mg BD) for 4 weeks; H. pylori eradication if positive
Rebleed after endoscopic therapy: Second attempt OGD → TIPSS or surgery if fails
Variceal: Continue terlipressin/octreotide for 5 days total; propranolol for secondary prophylaxis when stable

Pancreatitis Severity Algorithm

✅ Mild (Interstitial)

No organ failure
No local complications
Amylase/lipase elevation
CT: oedema only
Oral diet ASAP
Discharge 3–5 days
Mortality <1%

⚠️ Moderately Severe

Transient organ failure (<48h)
OR local complications
CTSI 4–6
Enteral nutrition early
HDU monitoring
Watch for deterioration
Mortality ~5%

🔴 Severe (Necrotising)

Persistent organ failure (>48h)
CTSI ≥7
Multi-organ dysfunction
ICU admission
LR resuscitation
Early EN within 24–48h
Antibiotics only if infected
Mortality 20–40%

🛡 6 · Stress Ulcer Prophylaxis

Stress Ulcer Prophylaxis in ICU

"Stress-related mucosal disease (SRMD) occurs in critically ill patients as a result of splanchnic hypoperfusion, increased gastric acid secretion, and breakdown of mucosal defence mechanisms. Clinically significant bleeding occurs in 1.5–8% of ICU patients without prophylaxis. Risk is highest in patients receiving mechanical ventilation for >48h or with coagulopathy — these are the two strongest evidence-based indications for stress ulcer prophylaxis."

Washington Manual of Critical Care, 4th Ed. Chapter: Stress-Related Mucosal Bleeding.

Indications for SUP (ASHP Guidelines + SUP-ICU Trial Evidence)

Strong indications (prescribe in all):
• Mechanical ventilation >48h STRONG
• Coagulopathy: INR >1.5 OR platelets <50 × 10⁹/L OR aPTT >2× normal

Additional risk factors (consider individually):
• Burns >35% BSA
• Head injury (Cushing's ulcer — direct gastric acid hypersecretion)
• History of GI ulceration in past year
• Glucocorticoid therapy (>250 mg/day hydrocortisone equivalent)
• Liver failure
• Renal replacement therapy

Low-risk patients (NO SUP needed): Enterally fed patients on IMV without coagulopathy — enteral nutrition itself is protective (buffers gastric pH)

Drug Choice — PPIs vs H₂ Blockers (SUP-ICU 2018 Trial)

SUP-ICU (NEJM 2018, n=3298): Pantoprazole vs placebo — no significant difference in 90-day mortality (31.1% vs 30.4%), but significant reduction in GI bleeding (3.7% vs 5.3%) CONDITIONAL
PPIs (omeprazole/pantoprazole): More effective at raising gastric pH; may slightly increase pneumonia risk (reduced gastric acid = less protection against oral colonisation)
H₂ blockers (ranitidine — now removed; famotidine): Comparable efficacy to PPIs in multiple trials; less pneumonia risk
Current practice: IV PPI (pantoprazole 40 mg OD IV) when NBM; switch to oral PPI when enteral route available; de-escalate as soon as risk factors resolve

⚠️ De-escalate SUP

Prolonged PPI use in ICU is associated with Clostridioides difficile infection, ventilator-associated pneumonia, hypomagnesaemia, and vitamin B₁₂ deficiency. Stop SUP as soon as the patient is haemodynamically stable, receiving enteral feeds, and extubated.

❌ 7 · Common Mistakes

Common Mistakes in GI Emergencies

❌ Mistake 1 — Keeping Pancreatitis Patients Nil-by-Mouth Until Amylase Normalises

Amylase normalisation is irrelevant to feeding decisions — it often stays elevated for days after clinical improvement. Early enteral nutrition (within 24–48h) in severe pancreatitis reduces infectious complications, gut barrier failure, and mortality. There is no "pancreatic rest" benefit from prolonged fasting — TPN alone worsens outcomes.

❌ Mistake 2 — Prophylactic Antibiotics in Necrotising Pancreatitis

Multiple RCTs (Isenmann 2004, Dellinger 2007) show no benefit of prophylactic imipenem/meropenem in sterile pancreatic necrosis. Routine antibiotic use increases MDR organism risk and fungal infections. Antibiotics are indicated ONLY when infection is confirmed (gas on CT, positive FNA, concurrent cholangitis).

❌ Mistake 3 — Over-Transfusing Upper GI Bleed

Liberal transfusion (Hb target 90 g/L) is associated with HIGHER rebleeding rates and mortality in UGIB, especially in variceal bleeding — it raises portal pressure. The TRIGGER trial established Hb 70 g/L as the transfusion threshold. Transfuse to 70–80 g/L unless concurrent ACS or cardiovascular compromise.

❌ Mistake 4 — Missing Aortoenteric Fistula

Any patient with prior aortic surgery (EVAR, open AAA repair) presenting with UGIB — no matter how minor — should be considered to have an aortoenteric fistula until proven otherwise. This condition has a characteristic "herald bleed" (minor bleed that stops spontaneously) followed by catastrophic exsanguination. CT aortogram is mandatory before OGD if there is any prior aortic surgery history.

❌ Mistake 5 — Using Normal Saline for Pancreatitis Resuscitation

Normal saline causes hyperchloraemic metabolic acidosis (Cl⁻ load), which independently worsens pancreatitis outcomes. Lactated Ringer's is strongly preferred — evidence from multiple RCTs and the WATERFALL trial 2022 confirms LR superiority. However, do not over-resuscitate — aggressive rapid fluid resuscitation increases fluid overload complications without improving organ failure.

❌ Mistake 6 — Giving Iodine (Lugol's) Before Antithyroid Drug in Thyroid Storm

(See Endocrine Emergencies topic for full detail) — applies when managing thyroid storm presenting with GI symptoms (vomiting, diarrhoea) alongside shock.

📑 8 · References

References

Barkun AN, Almadi M, Kuipers EJ et al. (ASGE). Management of Nonvariceal Upper Gastrointestinal Bleeding: Guideline Recommendations from the International Consensus Group. Ann Intern Med 2019;171:805–822. (ASGE 2021 update reinforces these recommendations)
Villanueva C, Colomo A, Bosch A et al. (TRIGGER Trial equivalent). Transfusion Strategies for Acute Upper Gastrointestinal Bleeding. NEJM 2013;368:11–21.
Frossard JL, Steer ML, Pastor CM. Acute pancreatitis. Lancet 2008;371:143–152.
Tenner S, Baillie J, DeWitt J, Vege SS. (ACG). American College of Gastroenterology Guideline: Management of Acute Pancreatitis. Am J Gastroenterol 2013;108:1400–1415.
Banks PA, Bollen TL, Dervenis C et al. Classification of Acute Pancreatitis — 2012: Revision of the Atlanta Classification and Definitions. Gut 2013;62:102–111. (Revised Atlanta Classification)
de-Madaria E, Buxbaum JL, Maisonneuve P et al. (WATERFALL Trial). Aggressive or Moderate Fluid Resuscitation in Acute Pancreatitis. NEJM 2022;387:989–1000.
Krag M, Marker S, Perner A et al. (SUP-ICU Trial). Pantoprazole in Patients at Risk for Gastrointestinal Bleeding in the ICU. NEJM 2018;379:2199–2208.
Singer P, Blaser AR, Berger MM et al. (ESPEN). ESPEN Guideline on Clinical Nutrition in the Intensive Care Unit. Clin Nutr 2019;38:48–79.
Marino PL. The ICU Book, 5th Ed. GI Failure; Nutrition in Critical Illness. Wolters Kluwer; 2025.
Washington Manual of Critical Care, 4th Ed. GI Haemorrhage; Stress-Related Mucosal Bleeding. Wolters Kluwer 2023.