USMLE Prep - Medical Reference Library

Acute Cholangitis — Diagnosis and Early Management

System: Gastroenterology • Reviewed: Aug 31, 2025 • Step 1Step 2Step 3

Synopsis:

Systemic infection from biliary obstruction; diagnose with Tokyo criteria; start broad-spectrum antibiotics and perform urgent biliary drainage (ERCP) based on severity.

Key Points

  • Stabilize ABCs; begin targeted evaluation without delaying life-saving therapy.
  • Use system-specific risk tools to guide testing and disposition.
  • Order high-yield tests first; escalate imaging when indicated.
  • Start evidence-based initial therapy and reassess frequently.

Algorithm

  1. Primary survey and vitals; IV access and monitors.
  2. Focused history/physical; identify red flags and likely etiologies.
  3. Order system-appropriate labs and imaging (see Investigations).
  4. Initiate guideline-based empiric therapy (see Pharmacology).
  5. Reassess response; arrange consultation and definitive management.

Clinical Synopsis & Reasoning

For Acute Cholangitis Dx Early Mgmt, frame the differential by acuity and pathophysiology, then align diagnostics to the leading hypotheses. Prioritize stabilization while obtaining high‑yield studies such as CBC (Bleeding/anemia), CMP (LFTs/electrolytes), Lipase (if pancreatitis) (Pancreatic enzyme), CT Abd/Pelvis (selected) (Complications). Incorporate bedside imaging and targeted labs to define severity and identify complications; synthesize results with clinical trajectory to refine the working diagnosis and disposition needs.


Treatment Strategy & Disposition

Initiate disease‑directed therapy alongside supportive care, titrating to objective response. Pharmacologic options commonly include PPI (IV), Octreotide (variceal). Use validated frameworks (e.g., Empiric Antibiotic Examples) to guide escalation and site of care. Address precipitating factors, de‑escalate empiric therapies with data, and arrange follow‑up for monitoring and risk‑factor modification; admit patients with instability, high risk of deterioration, or needs for close monitoring.


Epidemiology / Risk Factors

  • NSAIDs/alcohol; biliary disease

Investigations

TestRole / RationaleTypical FindingsNotes
CBCBleeding/anemiaLow Hgb
CMPLFTs/electrolytesAbnormal LFTs
Lipase (if pancreatitis)Pancreatic enzymeElevated
CT Abd/Pelvis (selected)ComplicationsFindings vary

Empiric Antibiotic Examples

SettingRegimen
Community acquiredCeftriaxone + metronidazole OR piperacillin–tazobactam
Severe or healthcare associatedPiperacillin–tazobactam or carbapenem

Pharmacology

MedicationMechanismOnsetRole in TherapyLimitations
Piperacillin-tazobactamβ-lactam/β-lactamase inhibitorHoursSevere biliary infectionAKI
Ceftriaxone + metronidazoleCephalosporin + nitroimidazoleHoursModerate diseaseAllergy
Analgesia/antiemeticSymptomatic controlMinutesSupportive careSedation; QT (ondansetron)

Prognosis / Complications

  • Varies by etiology and bleeding severity; rebleeding/perforation

Patient Education / Counseling

  • Explain red flags and when to seek emergent care.
  • Reinforce medication adherence and follow-up plan.

Notes

Give vitamin K if coagulopathic and consider reversal before sphincterotomy. Consult GI early for ERCP logistics.


References

  1. Tokyo Guidelines — Acute Cholangitis — Link
  2. ACG Biliary Infection Guidance — Link