Ventriculoperitoneal shunt infection

Background

• Occurrence
  • 50% within first 2 weeks of placement
  • 70% within 2 months of placement
  • 80% within 6 months of placement
  • 10% present >1 year after surgery

Types

• External Infection
  • Involve the subcutaneous tract around the shunt
• Internal Infection
  • Involves the shunt and CSF contained within the shunt

Bacteriology

• 50% of cases caused by S. epidermidis
• Also caused by S. aureus, Gram-negatives, anaerobes

Clinical Features

• Internal Infection
  • Mental status changes, HA, nausea and vomiting, irritability
  • Neck stiffness (33% of patients)
  • Fever is often absent
  • Abdominal pain (VP shunt)
• External Infection
  • Swelling, erythema, tenderness along site of shunt tubing

Differential Diagnosis

Ventriculoperitoneal shunt problems

• Ventriculoperitoneal shunt obstruction
• Ventriculoperitoneal shunt overdrainage (Slit Ventricle Syndrome)
• Ventriculoperitoneal shunt infection
• Ventriculoperitoneal shunt mechanical failure

Management

• Emergent neurosurgical consultation and admission
• Shunt tap
  • LP often misses CSF shunt infections and has no role when shunt infection is suspected
• Imaging
  • Useful to exclude mechanical shunt malfunction (often coexists with infection)
• Antibiotics
  • Cefepime/Ceftazidime or carbapenem + vancomycin

Pediatric

• Empiric therapy: Vancomycin age-based dosing AND Cefotaxime 200mg/kg/day IV div q6hrs OR Ceftriaxone 100mg/kg/day IV div q12-24hrs
• Always involve neurosurgery in management
• Tailor antimicrobial therapy to culture results