Absolute
  • Space occupying lesion with mass effect and evidence of increased ICP:
    • Risk of cerebral herniation
    • Suggested by midline shift or loss of cisterns on CT
  • Posterior fossa mass
  • Arnold-Chiari malformation
  • Coagulopathy (see BSN Guidance):
    • Platelets <40,000
    • INR >1.4
    • Anticoagulant & antiplatelet medication
  • Skin infection at puncture site
  • Patient refusal
Relative
  • Brain, spinal and epidural abscess
  • Issues with positioning:
    • Respiratory distress
    • Cardiovascular instability
    • Poor mobility
  • Spinal anomalies:
    • Congenital anomalies
    • Previous surgery
    • Degenerative disease