What is the evaluation and management of a patient presenting with symptoms of cholithiasis (formation of gallstones) versus cholecystitis (inflammation of the gallbladder)?

Cholelithiasis vs Cholecystitis: Evaluation and Management

Ultrasound is the first-line imaging test for both cholelithiasis and cholecystitis, with 96% accuracy for detecting gallstones and the ability to differentiate simple stone disease from acute inflammation requiring urgent intervention. 1

Key Clinical Distinctions

Cholelithiasis (Gallstones Alone)

• Presentation: May be asymptomatic or cause intermittent biliary colic—right upper quadrant pain without fever or inflammatory signs 2
• Physical exam: Right upper quadrant tenderness may be present but Murphy's sign is typically absent 1
• Laboratory: Normal white blood cell count and C-reactive protein 1

Acute Cholecystitis (Inflamed Gallbladder)

• Presentation: Right upper quadrant pain, fever, nausea/vomiting, and food intolerance 1
• Physical exam: Murphy's sign (focal tenderness over sonographically localized gallbladder) has a positive likelihood ratio of 2.8, though specificity is limited 1
• Laboratory: Elevated white blood cell count and C-reactive protein 1
• Critical point: No single clinical or laboratory finding can definitively rule in or rule out cholecystitis; combinations of findings yield diagnostic impressions with positive likelihood ratios of 25-30 3

Diagnostic Algorithm

Initial Imaging: Ultrasound for All Patients

Ultrasound is the mandatory first test regardless of suspected diagnosis 1

For cholelithiasis detection:

• Sensitivity/specificity: 96% accuracy for gallstones 1
• Differentiates stones from sludge, polyps, or masses 1

For acute cholecystitis diagnosis:

• Sensitivity: 88% (95% CI: 74%-100%)
• Specificity: 80% (95% CI: 62%-98%) 1
• Key findings: Gallbladder wall thickening, pericholecystic fluid, distended gallbladder, stones impacted in cystic duct, sonographic Murphy's sign 1

Important caveat: Ultrasound has limited utility in critically ill patients where gallbladder abnormalities are common without true cholecystitis 1

Second-Line Imaging When Ultrasound is Equivocal

If acute cholecystitis suspected but ultrasound equivocal:

• Tc-99m cholescintigraphy is the preferred next test with superior diagnostic accuracy:
  • Sensitivity: 97% (95% CI: 96%-98%)
  • Specificity: 90% (95% CI: 86%-95%) 1
  • Gallbladder nonvisualization indicates cystic duct obstruction and confirms cholecystitis 1

Alternative advanced imaging:

• MRI with MRCP: Sensitivity 85% (95% CI: 66%-95%), specificity 81% (95% CI: 69%-90%) for cholecystitis 1

  • Superior for detecting choledocholithiasis (common bile duct stones): 85-100% sensitivity, 90% specificity 1
  • Better visualization of cystic and common bile ducts than ultrasound 1
  • Can distinguish acute from chronic cholecystitis based on T2 signal characteristics 1

• CT with IV contrast: Not first-line but useful when ultrasound negative and alternative diagnoses need exclusion 1

  • Can detect complications (emphysematous, gangrenous, perforated cholecystitis) 4
  • Adjacent liver hyperemia is an early finding in acute cholecystitis 1

Management Based on Diagnosis

Asymptomatic or Minimally Symptomatic Cholelithiasis

Watchful waiting is appropriate 5, 6

• Risk of developing moderate-to-severe symptoms: 2-6% per year, cumulative 7-27% over 5 years 5
• No intervention required unless symptoms develop 6

Symptomatic Cholelithiasis (Biliary Colic)

Refer to surgeon/gastroenterologist within 2 weeks regardless of symptom severity 2

Treatment options:

• Laparoscopic cholecystectomy: Definitive treatment for recurrent symptoms 6, 2
• Medical dissolution therapy with ursodiol: For patients refusing surgery or non-surgical candidates 5, 6
  • Requires radiolucent stones
  • Partial dissolution within 6 months predicts >70% chance of complete dissolution 5
  • Stone recurrence occurs in 30-50% within 2-5 years after dissolution 5

Uncomplicated Acute Cholecystitis

Early laparoscopic cholecystectomy within 7-10 days of symptom onset is the definitive treatment 1

• Single-shot antibiotic prophylaxis only; no postoperative antibiotics needed 1

Alternative delayed approach (not for immunocompromised):

• Antibiotic therapy for no more than 7 days followed by planned delayed cholecystectomy 1

Antibiotic regimens for uncomplicated cholecystitis:

• Non-critically ill, immunocompetent: Amoxicillin/clavulanate 2g/0.2g q8h 1
• Critically ill or immunocompromised: Piperacillin/tazobactam 6g/0.75g loading dose, then 4g/0.5g q6h or 16g/2g continuous infusion 1
• Beta-lactam allergy: Eravacycline 1 mg/kg q12h or tigecycline 100mg loading dose then 50mg q12h 1

Complicated Acute Cholecystitis

Immediate laparoscopic or open cholecystectomy required 1

Antibiotic duration:

• Immunocompetent, non-critically ill with adequate source control: 4 days 1
• Immunocompromised or critically ill with adequate source control: Up to 7 days based on clinical response and inflammatory markers 1
• Ongoing infection beyond 7 days warrants diagnostic investigation for complications 1

Cholecystostomy option: For patients with multiple comorbidities unfit for surgery who fail antibiotic therapy, though inferior to cholecystectomy for critically ill patients 1

High-risk antibiotic regimens (inadequate source control or ESBL risk):

• Ertapenem 1g q24h or eravacycline 1 mg/kg q12h 1

Septic shock regimens:

• Meropenem 1g q6h by extended/continuous infusion, or doripenem 500mg q8h by extended/continuous infusion, or imipenem/cilastatin 500mg q6h by extended infusion 1

Critical Pitfalls to Avoid

• Do not rely on Murphy's sign alone—it has low specificity and is unreliable if patient received pain medication before examination 1
• Do not use CT as first-line imaging—ultrasound must be performed first 1
• Do not skip cholescintigraphy when ultrasound is equivocal—it has the highest sensitivity/specificity for cholecystitis 1
• Do not delay surgery in immunocompromised patients—delayed cholecystectomy is contraindicated in this population 1
• Do not continue antibiotics beyond 7 days without investigating for complications 1