What are the symptoms of Spontaneous Bacterial Peritonitis (SBP)?

Symptoms of Spontaneous Bacterial Peritonitis (SBP)

Patients with spontaneous bacterial peritonitis may present with a wide range of symptoms from asymptomatic to severe systemic inflammation, with up to one-third of patients being entirely asymptomatic or presenting only with worsening of liver function or encephalopathy. 1

Common Clinical Presentations

Local Symptoms and Signs

• Abdominal pain (most common local symptom) 1, 2
• Abdominal tenderness on palpation (with or without rebound tenderness) 1
• Vomiting 1
• Diarrhea 1
• Ileus 1
• Worsening ascites 3

Systemic Manifestations

• Fever or hypothermia 1, 3
• Chills 1
• Altered white blood cell count 1
• Tachycardia 1
• Tachypnea 1

Complications and Deterioration Signs

• Worsening of liver function 1
• Hepatic encephalopathy (may be the only presenting symptom) 1
• Shock 1
• Renal failure/acute kidney injury 1
• Gastrointestinal bleeding 1
• Altered mental status 3

Important Clinical Considerations

Asymptomatic Presentation

• Up to one-third of patients with SBP may be entirely asymptomatic 1, 2
• Diagnosis may be missed if paracentesis is not performed routinely in at-risk patients

High-Risk Scenarios

• All patients with cirrhosis and ascites are at risk of SBP 1
• Prevalence in outpatients: 1.5-3.5% 1
• Prevalence in hospitalized patients: 10% 1
• Half of SBP episodes are present at hospital admission, while the rest are acquired during hospitalization 1

Diagnostic Pitfalls

1. Subtle presentation: The clinical presentation can be subtle or even absent in many cases 2
2. Mistaking for other conditions: Symptoms may be attributed to worsening of underlying liver disease rather than infection
3. Delayed diagnosis: Each hour of delay in diagnosis is associated with a 3.3% increase in mortality 2

When to Suspect SBP

SBP should be suspected in any patient with cirrhosis and ascites who:

• Presents with new-onset fever, abdominal pain, or tenderness
• Shows unexplained deterioration in clinical condition
• Develops worsening encephalopathy
• Has acute kidney injury
• Is admitted to the hospital for any reason (even without symptoms suggestive of infection) 1
• Presents with gastrointestinal bleeding 1

Diagnostic Approach

A diagnostic paracentesis should be performed immediately in all patients with cirrhosis and ascites who:

• Are admitted to the hospital emergently for any reason 1, 2
• Develop signs of infection, worsening liver or renal function 1, 2
• Present with hepatic encephalopathy 1, 2
• Have gastrointestinal bleeding 1, 2
• Develop shock 2

The diagnosis is confirmed by an ascitic fluid neutrophil count >250/mm³ in the absence of an intra-abdominal surgically treatable source of infection 1, 2.

Clinical Pearls

1. Don't wait for classic symptoms: Many patients with SBP don't present with the classic triad of fever, abdominal pain, and ascites
2. Consider SBP in any deterioration: Any unexplained deterioration in a patient with cirrhosis and ascites should prompt consideration of SBP
3. Early paracentesis saves lives: Perform diagnostic paracentesis promptly, as each hour of delay increases mortality by 3.3% 2
4. Don't miss bacterascites: Patients with positive ascitic fluid culture but normal neutrophil count may still require treatment if symptomatic 1

By maintaining a high index of suspicion and performing prompt diagnostic paracentesis in at-risk patients, early diagnosis and treatment of SBP can significantly reduce the associated mortality.