EM · Procedural & diagnostic ED skills

Lumbar puncture in the emergency department

Also known as Lumbar puncture · LP · Spinal tap · Cerebrospinal fluid sampling · CSF analysis

Lumbar puncture in the ED — the indications (suspected meningitis or encephalitis, subarachnoid haemorrhage after a negative CT, demyelinating disease — multiple sclerosis, CIDP, Guillain-Barre, and the therapeutic uses — idiopathic intracranial hypertension, cryptococcal meningitis, intrathecal drug delivery), the contraindications (raised intracranial pressure with papilloedema or a focal deficit, coagulopathy with an INR over 1.4 or platelets under 50, overlying skin infection), the anatomy (the conus at L1/L2, the dural sac at S2, Tuffier's line crossing L4), the technique (L3/L4 or L4/L5, midline, the bevel parallel to the longitudinal dural fibres, the atraumatic over the cutting needle), the CSF interpretation (bacterial — high neutrophils, low glucose; viral — lymphocytes, normal glucose; TB — very low glucose, very high protein; SAH — xanthochromia and uniform red cells), and the post-dural puncture headache (atraumatic needle halves it; caffeine and the epidural blood patch treat it). ACEM-primary, globally tagged.