Spontaneous Bacterial Peritonitis in Children

Spontaneous Bacterial Peritonitis in Children? I know, you are shaking your head right now. “Come on, Fox! I’ve never seen that before in a kid. That is an adult problem.” Well, while it may not be common, it may occur at any age and is based on your patient’s underlying medical comorbidities, like Pulmonary Embolism, Cholecystitis, and Neprholithiasis. So, to ensure we do not treat this issue with a cavalier attitude or get caught off guard, let’s take one minute to digest a morsel on Spontaneous Bacterial Peritonitis in Children:

Spontaneous Bacterial Peritonitis: Basics

  • Ascites = accumulated fluid in the peritoneal cavity.
    • Due to a variety of complex processes. [Sabri, 2003]
      • Increased hydrostatic pressure within hepatic / splanchnic blood vessels
      • Decreased colloid osmotic pressure within the hepatic / splanchnic vessels
      • Increased permeability of peritoneal capillaries
      • Direct leakage of fluids from organs
    • Due to numerous underlying conditions: [Sabri, 2003]
  • Patients with end-stage liver disease (and many of these other conditions) have baseline immunodeficiencies: [Srivastava, 2017; Vieira, 2005]
    • Increased permeability of the interesting mucosal barrier
    • Intestinal bacterial overgrowth
    • Decreased protein levels (ex, Low C3 and C4 levels)
    • Defects in complement system
    • Defects in neutrophil activity
    • Decreased cytokine response
  • Infected Ascites: [Srivastava, 2017; Vieira, 2005]
    • Potentially life-threatening
    • Associated with septic shock, encephalopathy, and renal failure
    • Can be classified as:
      • Spontaneous Bacterial Peritonitis (SBP)
      • Culture Negative Neutrocytic Ascites (CNNA)
      • Monomicrobial Non-Neutrocytic Bacterascites
      • SBP refers to bacterial peritonitis that is not associated with gut perforation or secondary cause of infection. [El-Shabrawi, 2011]
      • SBP and CNNA are treated similarly initially.
    • Infected ascites occurs most often in children with Chronic Liver Disease, then next most commonly in patients with acute viral hepatitis and acute liver failure.
    • Infected Ascites occurs in ~29% of pediatric patients with ascites. [Srivastava, 2017; Vieira, 2005]
  • Presentation of Spontaneous Bacterial Peritonitis can be subtle. [Bes, 2017; Srivastava, 2017; El-Shabrawi, 2011; Vieira, 2005]
    • Unfortunately, SBP cannot be diagnosed solely by clinical signs and symptoms.
    • Patients with infected ascites are difficult to distinguish from those without infected ascites based only on exam and initial lab results.
    • ~50% of patients with SBP/CNNA were asymptomatic! [Srivastava, 2017]
  • SBP should be considered and paracentesis performed in patients with: [Bes, 2017; Srivastava, 2017; El-Shabrawi, 2011; Vieira, 2005]
    • Fever, abdominal pain, and/or chills
    • Signs of systemic infection
    • Worsening ascites or 1st ascites episode
    • Worsening renal function
    • Encephalopathy
    • Consider diagnostic paracentesis in those with recent hospitalization or current need to hospitalization.

Spontaneous Bacterial Peritonitis: Evaluation

  • Diagnostic Paracentesis
    • Can be performed safely at the bedside, even with concurrent clotting system disorders. [Sabri, 2003]
    • Use of ultrasound is helpful to define greatest region of ascites accumulation and avoid blood vessels and intestines.
  • Ascites Laboratory Evaluation: [Vieira, 2005; Sabri, 2003]
    • Color
      • Typically amber in color, although may be clear if protein level is very low.
      • Opacity / Cloudy color usually due to neutrophils.
      • Milky color? Think chylous ascites (from thoracic duct blockage/injury).
    • Cell Count and Differential
      • Leukocyte Count
        • Should be < 250 cells / mm^3, with lymphocyte predominance.
        • Polymorphonuclear (PMN) count > 250 suggest Spontaneous Bacterial Peritonitis!
      • Erythrocytes should be < 10,000 cells/mm^3
    • Protein concentration is usually <2.5 g/dL… may reflect low ascitic bactericidal activity. [Vieira, 2005]
    • Glucose level (may be <30 mg/dL with tuberculous peritonitis)
    • Amylase level (may be elevated in pancreatic ascites)
    • Triglyceride level (may be >400 mg/dL in chylous ascites)
    • Lactate level (may be elevated with intra-abdominal malignancy)
    • Bilirubin Level (may be elevated with biliary tract leakage)
    • Creatinine Level (may be elevated with urinary tract abnormalities)
    • Gram Stain
    • Cytology
    • Bacterial Culture (both anaerobic and aerobic)
      • Inoculation of ascitic fluid into blood culture bottles at the bedside leads to better yield for fluid culture.
      • Cultures are negative in up to 50% of cases of SBP. [Vieira, 2005]

Spontaneous Bacterial Peritonitis: Management

  • PMN count > 250 cells/mm^3 warrant empiric IV antibiotics. [Sabri, 2003]
  • Give antibiotics: [Srivastava, 2017; Vieira, 2005]
    • In children, common bacteria include:
      • E. coli
      • K. pneumoniae
      • S. pneumoniae
      • H. influenzae
      • N. meningitides
      • Anaerobic organisms are less common.
    • Broad spectrum coverage is warranted.
      • Cefotaxime 100-200 mg/day divided q6-8, max 12g/day is 1st choice.
      • Cetriaxone 50-75 mg/kg/day divided q12-24, max 2 g/day
      • Amp/Sulbactam 100-150 mg/kg/day divided q6
      • If culture results become available, antibiotic selection can be tailored based on susceptibilities.
  • Intravenous albumin
    • 20-25% at 1 g/kg [Bes, 2017]
    • Has been shown to help, likely by decreasing renal impairment. [El-Shabrawi, 2011]
  • Other supportive therapies for Ascites [El-Shabrawi, 2011]
    • Sodium and water restriction
    • Careful diuresis
    • Colloid expansion
    • Support caloric / protein intake

Moral of the Morsel

  • Fluid Likes to Get Infected. Keep SBP on your Ddx anytime you have a patient with ascites.
  • Don’t trust your exam. Lack of fever and pain does not rule out SBP.
  • Don’t wait for the Culture Results. If PMN count is >250 cells/mm^3, treat empirically.

Sean M. Fox

I enjoy taking care of patients and I finding it endlessly rewarding to help train others to do the same. I trained at the Combined Emergency Medicine and Pediatrics residency program at University of Maryland, where I had the tremendous fortune of learning from world renowned educators and clinicians. Now I have the unbelievable honor of working with an unbelievably gifted group of practitioners at Carolinas Medical Center. I strive every day to inspire my residents as much as they inspire me.

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