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Spontaneous Bacterial Peritonitis — Diagnostic Tap, Albumin, and Third-Generation Cephalosporins

System: Hepatology • Reviewed: Sep 2, 2025 • Step 1Step 2Step 3

Synopsis:

In any cirrhotic with ascites and abdominal pain or encephalopathy, perform diagnostic paracentesis; PMN ≥250 cells/mm³ confirms SBP. Start cefotaxime or ceftriaxone promptly and give albumin on day 1 and 3 to prevent renal failure; begin long-term prophylaxis after recovery when indicated.

Key Points

  • Use the highest‑yield diagnostic test early; do not let testing delay time‑critical therapy.
  • Set objective targets and reassess frequently.
  • Plan definitive source control or disease‑specific therapy when indicated; document follow‑up and patient education.

Algorithm

  1. Perform paracentesis before antibiotics when safe; diagnose with PMN ≥250.
  2. Start cefotaxime/ceftriaxone and albumin; manage complications; stop diuretics if AKI.
  3. Plan secondary prophylaxis; evaluate for transplant; vaccination and counseling.

Clinical Synopsis & Reasoning

In any cirrhotic with ascites and abdominal pain or encephalopathy, perform diagnostic paracentesis; PMN ≥250 cells/mm³ confirms SBP. Start cefotaxime or ceftriaxone promptly and give albumin on day 1 and 3 to prevent renal failure; begin long-term prophylaxis after recovery when indicated.


Treatment Strategy & Disposition

Stabilize ABCs. Initiate guideline‑concordant first‑line therapy with precise dosing and continuous monitoring. Escalate to advanced/procedural interventions based on explicit failure criteria. Define ICU, step‑down, and ward disposition triggers; involve specialty teams early.


Epidemiology / Risk Factors

  • Risk varies by comorbidity and precipitants; see citations for condition‑specific data.

Investigations

TestRole / RationaleTypical FindingsNotes
Ascitic fluid cell count, albumin, culture in blood culture bottlesDiagnosisPMN ≥250, SAAG, organism IDEssential first step
Renal function and bilirubinPrognosisAKI risk guides albumin dosing
Ultrasound for ascites and complicationsAdjunctGuide tap and r/o loculations

High-Risk & Disposition Triggers

TriggerWhy it mattersAction
Sepsis, hypotension, or AKIHigh mortalityICU; albumin for renal protection
SBP recurrence or MDR organismsTreatment failure riskID consult; adjust antibiotics
GI bleedingInfection risk ↑Prophylactic antibiotics
Severe hyponatremia/hepatic encephalopathyDecompensationClose monitoring
Transplant candidatePrognosisNotify transplant team

Pharmacology

Medication/InterventionMechanismOnsetRole in TherapyLimitations
Cefotaxime 2 g IV q8h or Ceftriaxone 2 g IV dailyAntibioticsHoursFirst-line empiric therapyAdjust to culture
Albumin 1.5 g/kg day 1 + 1.0 g/kg day 3Renal protectionDaysPrevents HRS/AKIDose by weight
Norfloxacin/TMP‑SMX for secondary prophylaxisPreventionDaysReduce recurrenceAvoid with resistance issues

Prognosis / Complications

  • Outcome depends on timeliness of diagnosis and definitive therapy; monitor for complications.

Patient Education / Counseling

  • Provide red‑flag education, adherence guidance, and explicit return precautions; arrange timely specialty follow‑up.

References

  1. AASLD ascites/SBP guidance — Link

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