Facts About Acute Cholecystitis
Acute cholecystitis is primarily associated with gallstones, with approximately 90-95% of cases being calculous cholecystitis, while only 5-10% are acalculous in nature. 1
Etiology and Pathophysiology
- Gallstone Association: 90-95% of acute cholecystitis cases are associated with gallstones (calculous cholecystitis) 1
- Acalculous Cholecystitis: Only 5-10% of cases occur without stones 1
- Bacterial Involvement: Bacterial infection is a secondary event, not the primary cause of acute cholecystitis 1
- Culture Results: Positive bacterial cultures are found in only 20-40% of cases 1
- Common Organisms: When positive, cultures typically show E. coli, Klebsiella, Enterococcus, and anaerobes 1
Diagnostic Considerations
Clinical Presentation
- Right upper quadrant pain or tenderness
- Fever
- Nausea and vomiting
- Murphy's sign (pain on palpation during inspiration)
- Leukocytosis and elevated inflammatory markers (CRP)
Imaging Studies
- Ultrasound: First-line imaging modality with high sensitivity (81%) and specificity (83%) for detecting gallstones 1
- HIDA Scan: Most accurate test for diagnosing acute cholecystitis 1
- A normal HIDA scan effectively rules out acute cholecystitis 1
- Non-visualization of the gallbladder on HIDA scan indicates cystic duct obstruction, which is highly suggestive of acute cholecystitis
- CT Scan: Less sensitive than ultrasound for gallstones but better for identifying complications such as perforation or emphysematous cholecystitis 1
Management Approach
- Early Laparoscopic Cholecystectomy: Preferred treatment within 72 hours of diagnosis 1
- Medical Management: Before surgery, includes fasting, IV fluids, antimicrobial therapy, and analgesia 2
- Alternative Approaches: Percutaneous cholecystostomy for critically ill patients unfit for surgery 2
Important Caveats
- No single clinical or laboratory finding has sufficient diagnostic power to establish or exclude acute cholecystitis 1
- Diagnosis requires a combination of history, physical examination, laboratory tests, and imaging 1
- Delaying surgical intervention results in longer hospital stays and more complications 1
- Misinterpreting normal HIDA scans can lead to incorrect diagnosis 1
- Acute cholecystitis may present atypically without classic findings such as leukocytosis, fever, or positive Murphy's sign 3
Based on the evidence provided, option A (75% associated with stone) is incorrect as 90-95% of acute cholecystitis cases are associated with gallstones. Option B (Positive with organism) is incorrect as only 20-40% of cases have positive bacterial cultures. Option C (HIDA scan normal even with acute cholecystitis) is incorrect as a normal HIDA scan effectively rules out acute cholecystitis.