Acute Cholecystitis

Acute gallbladder inflammation from cystic duct obstruction — calculous (90%) or acalculous (critically ill)

Symptoms / Associated Sx

  • RUQ or epigastric pain — constant, worsening over hours (unlike biliary colic which waxes/wanes)

  • Fever, chills, nausea, vomiting, anorexia

  • Murphy's sign (inspiratory arrest with deep RUQ palpation)

  • RUQ tenderness with guarding

Denies

  • Jaundice (rules out concurrent CBD stone/cholangitis if absent)

  • Fever + jaundice + RUQ pain together (raises cholangitis, not isolated cholecystitis)

  • Hemodynamic instability (rules out gangrenous/emphysematous if absent — do not be falsely reassured)

Social History (SHx)

"5 Fs" risk factors (female, fat, forty, fertile, fair), prior biliary colic, prolonged fasting/TPN (acalculous), ICU admission, sickle cell disease, rapid weight loss.

Main Etiology

  • Calculous (90%): cystic duct obstruction by gallstone → bile stasis → inflammation → secondary infection

  • Acalculous (10%): critically ill (ICU, TPN, burns, major surgery) — bile stasis without stones; higher mortality

  • Gangrenous: necrosis — diabetics, elderly, delayed presentation

  • Emphysematous: gas-forming organisms (Clostridium, E. coli) — diabetics; surgical emergency

Most Common DDx

  • Acute cholangitis (RUQ pain + fever + jaundice = Charcot's triad; CBD dilation with stone; CBD dilated vs. normal in isolated cholecystitis)

  • Acute pancreatitis (epigastric pain radiating to back; lipase >3× ULN; may coexist — check both; no Murphy's sign)

  • Perforated peptic ulcer (sudden-onset severe epigastric pain; free air on imaging; rigid abdomen; no Murphy's sign)

  • Appendicitis (RLQ pain; migration from periumbilical; rebound at McBurney's; CT confirms; no biliary findings)

  • Hepatic abscess (fever + RUQ pain; CT shows hypodense collection in liver parenchyma; gallbladder normal)

  • Right lower lobe pneumonia (fever + RUQ/right-sided pain from diaphragmatic irritation; CXR consolidation; no gallbladder findings)

  • Acalculous cholecystitis (same presentation but no stones on US; critically ill patients; HIDA confirms; higher mortality)

DATA

  • CBC (WBC >10k); CMP (LFTs, bilirubin — if elevated, suspect CBD stone); lipase (concurrent pancreatitis); PT/INR

  • Blood cultures (if febrile + systemic signs)

  • RUQ ultrasound (first-line: gallstones, wall thickening >4 mm, pericholecystic fluid, sonographic Murphy's)

  • HIDA scan (gold standard — non-visualization of GB = cystic duct obstruction; use if US equivocal)

  • CT (complications — gangrenous, emphysematous, perforation)

Home Meds

  • Anticoagulants (hold; reverse for emergent surgery); antiplatelets (hold 5–7 days)

  • Diabetes medications (hold during NPO)

Plan

  • NPO; IV fluid resuscitation; analgesia (ketorolac 15–30 mg IV q6h ± hydromorphone 0.2–0.4 mg IV q4h PRN)

  • Antibiotics:

    • Mild (TG I): Cefazolin 1–2 g IV q8h or ampicillin-sulbactam 3 g IV q6h

    • Moderate (TG II): Piperacillin-tazobactam 3.375 g IV q6h

    • Severe/complicated/healthcare-associated: Meropenem 1 g IV q8h ± Vancomycin

  • Cholecystectomy:

    • Laparoscopic — preferred; early surgery (<72h) reduces complications and LOS

    • High surgical risk: percutaneous cholecystostomy → interval cholecystectomy at 6–8 weeks

    • Gangrenous or emphysematous → emergent surgery

  • Surgery consult immediately; daily CBC, CMP, LFTs; trend fever curve

  • PT/OT pre- and post-operatively

  • Discharge: Low-fat diet × 4–6 weeks; return precautions: fever, worsening pain, jaundice; surgery follow-up 2–4 weeks; if cholecystostomy tube: interval cholecystectomy scheduling 6–8 weeks

Red Flags

  • Emphysematous cholecystitis (gas in GB wall on CT) → emergent surgery; high mortality in diabetics

  • Gangrenous cholecystitis → emergent surgery; clues: severe pain, WBC >20k, diabetes, elderly

  • Gallbladder perforation → emergent surgery + IR drainage

  • Charcot's triad = cholangitis complicating cholecystitis → ERCP + antibiotics urgently

  • Acalculous cholecystitis in ICU → high index of suspicion; HIDA or CT; percutaneous cholecystostomy if too ill

Senior IM Resident Pearls

  • Tokyo Guidelines 2018 grade severity: Grade I = mild; Grade II = moderate (local complications); Grade III = severe (organ failure) — drives surgical urgency

  • Early laparoscopic cholecystectomy (<72h) is superior to delayed — reduces LOS by 3–4 days, reduces readmissions (ACDC trial)

  • HIDA scan most sensitive/specific when US equivocal — non-filling of GB at 4h = cystic duct obstruction

  • Acalculous cholecystitis — higher morbidity/mortality; occurs in burns, post-op, TPN, sepsis; lower threshold for diagnosis in ICU patients with unexplained fever

  • Common mistake: Delaying cholecystectomy for "cooling off" — early surgery is now standard of care

  • Common mistake: Attributing all LFT elevation to cholecystitis — any jaundice or CBD dilation → MRCP/ERCP to rule out Mirizzi syndrome or choledocholithiasis

ORDERS

Labs

Admission Labs

  • CBC with diff

  • CMP

  • BMP

  • LFTs (AST, ALT, ALP, GGT, total/direct bilirubin)

  • PT/INR

  • PTT

  • Lipase

  • Magnesium

  • Phosphorus

Additional Labs

  • Blood cultures ×2 (if febrile/systemic signs)

  • Lactate (sepsis concern)

  • Type & Screen (operative planning)

  • HbA1c if diabetes history

Trending Labs

  • CBC daily

  • CMP daily

  • LFTs daily

  • BMP daily

  • Fever curve

  • Blood culture results

Imaging

First-Line

RUQ Ultrasound

Evaluate:

  • Gallstones

  • Gallbladder wall thickening (>4 mm)

  • Pericholecystic fluid

  • Sonographic Murphy sign

  • CBD dilation

If Ultrasound Equivocal

HIDA Scan

Gold standard:

  • Nonvisualization of gallbladder

  • Cystic duct obstruction

If Complications Suspected

CT Abdomen/Pelvis with Contrast

Evaluate:

  • Gangrenous cholecystitis

  • Emphysematous cholecystitis

  • Perforation

  • Abscess

If CBD Stone Suspected

MRCP

OR

ERCP

If:

  • Jaundice

  • Elevated bilirubin

  • CBD dilation

Procedures

Surgery (Definitive)

Laparoscopic Cholecystectomy

Preferred:

  • Within 72 hr of symptom onset

  • Same hospitalization

High Surgical Risk

Percutaneous Cholecystostomy Tube

  • IR placement

  • Interval cholecystectomy in 6–8 weeks

Emergent Surgery

Indications:

  • Gangrenous cholecystitis

  • Emphysematous cholecystitis

  • Perforation

  • Sepsis with source not controlled

Medications

Supportive Care

NPO

IV Fluids

LR Preferred

  • 100–150 mL/hr

  • Additional boluses PRN

Pain Control

First-Line

  • Ketorolac 15–30 mg IV q6h PRN

Severe Pain

  • Hydromorphone 0.2–0.4 mg IV q4h PRN

Alternative

  • Oxycodone 5–10 mg PO q4–6h PRN

Antiemetics

Ondansetron

  • 4 mg IV q6h PRN

Antibiotics

Mild (Tokyo Grade I)

Cefazolin

  • 1–2 g IV q8h

OR

Ampicillin-Sulbactam

  • 3 g IV q6h

Moderate (Tokyo Grade II)

Piperacillin-Tazobactam

  • 4.5 g IV q6h

Severe / Complicated / HCAI

Meropenem

  • 1 g IV q8h

Add Vancomycin If

  • MRSA risk

  • Healthcare-associated infection

Vancomycin

  • 15–20 mg/kg IV q8–12h

Duration

Uncomplicated

  • Usually stop within 24 hr after cholecystectomy

Severe/Complicated

  • 4–7 days after source control

Hold Medications

Before Surgery

  • Warfarin

  • DOACs

  • Heparin

  • Clopidogrel

  • Ticagrelor

Hold While NPO

  • Oral diabetes medications

Consults

General Surgery (Immediate)

  • All confirmed cholecystitis

Gastroenterology

If:

  • Suspected choledocholithiasis

  • Elevated bilirubin

  • CBD dilation

  • Need ERCP

Interventional Radiology

  • Cholecystostomy tube

  • Poor operative candidate

ICU

If:

  • Organ failure

  • Septic shock

  • Gangrenous disease

PT/OT

  • Pre-op/post-op mobility

  • Deconditioning

Nursing Orders

Monitoring

  • Vital signs q4 hr

  • Strict I&O

  • Daily weights

Diet

  • NPO until surgical plan established

Notify Physician Immediately

  • Fever

  • Hypotension

  • Jaundice

  • Worsening RUQ pain

  • AMS