Acute Cholecystitis
General Surgery
Illness script · General Surgery
Acute Cholecystitis
Acute gallbladder wall inflammation, usually from cystic duct obstruction by a gallstone, causing RUQ pain, fever, and leukocytosis.
This illness script for Acute Cholecystitis covers predisposing factors, classic presentation, mechanism, workup, management, and the clinical pivots that separate it from look-alikes—written for USMLE Step 1 and clerkship reasoning.
01
Predisposing factors
- Classic '5 Fs': Female, Fat, Forty, Fertile, Flatulent
- Gallstones present in >90% of cases (calculous)
- Acalculous form in critically ill, ICU, or post-op patients
- Rapid weight loss, TPN, prolonged fasting favor stone formation
- Native American and Hispanic populations at highest risk
02
Presentation
- RUQ or epigastric pain >6 hours, radiating to right shoulder/scapula
- Fever and leukocytosis distinguishes from biliary colic
- Murphy's sign: inspiratory arrest on deep RUQ palpation (pathognomonic)
- Nausea, vomiting, anorexia common
- Pain onset often after fatty meal; persistent (vs. colic which resolves <6h)
- Elderly/diabetics may present atypically with minimal pain
03
Pathophysiology
- Gallstone impacts cystic duct → sustained obstruction (unlike biliary colic)
- Bile stasis → chemical irritation, mucosal injury, wall edema
- Secondary bacterial infection (E. coli, Klebsiella) in ~50%
- Acalculous: bile stasis + ischemia without stone obstruction
04
Diagnostics
- RUQ ultrasound: first-line — gallstones, wall thickening >4mm, pericholecystic fluid, sonographic Murphy's sign
- Labs: leukocytosis, mild LFT elevation; marked LFT/bili elevation → choledocholithiasis
- HIDA scan: gold standard if ultrasound equivocal — non-visualization of gallbladder confirms obstruction
- CT useful for complications (perforation, emphysematous cholecystitis)
- Pearl: normal WBC does not exclude diagnosis, especially in elderly
05
Management
- NPO, IV fluids, analgesia (NSAIDs or opioids), antibiotic coverage (gram-negative/anaerobes)
- Laparoscopic cholecystectomy: definitive treatment, ideally within 24–72 hours of admission
- Early surgery (within 72h) preferred over delayed — lower conversion rate, shorter hospitalization
- Percutaneous cholecystostomy tube for critically ill patients who cannot tolerate surgery
- Avoid delay >72h — increases risk of perforation, empyema, gangrenous cholecystitis
06
Clinical pivots
How to separate this script from the look-alikes that show up on exams and on the wards.
Biliary Colic
Pain resolves within 6 hours; no fever, no leukocytosis, negative Murphy's sign
Choledocholithiasis / Cholangitis
Charcot's triad (fever, jaundice, RUQ pain); markedly elevated bilirubin and ALP
Peptic Ulcer Disease
Epigastric pain relieved by antacids; no Murphy's sign; associated with NSAID/H. pylori use
Hepatitis
Diffuse liver tenderness, markedly elevated transaminases (AST/ALT), no gallstones on US
Keep reading
Full library- Acute AppendicitisAcute inflammation of the vermiform appendix, most commonly from luminal obstruction, causing right lower quadrant pain and peritoneal signs.
- Acute Compartment SyndromeElevated pressure within a closed fascial compartment compromises perfusion, causing ischemia and irreversible muscle/nerve damage if untreated.
Educational use only. This illness script is a study framework, not medical advice. Confirm decisions with current guidelines and your clinical supervisors.