Lumbar Puncture (LP)

Indications

Requirements

Technique

Precautions

Indications

1.  In cases of suspected neonatal sepsis (even if clinical signs of CNS infection are absent)
2.  Infants with convulsions
3.  Intraventricular haemorrhage

Requirements

• Sterile LP-pack
• Blood gas needle (25G) or butterfly needle Nr 25 or spinal needle Nr. 24-26
• Sterile specimen tubes
• Hibitane-alcohol en iodine disinfectants
• (1% Lignocaine for local anaesthesia)
• Sterile gloves

Technique

• Discuss the method of local anaesthesia with the consultant.
• Position the baby in the lateral decubitus position
• An assistant must support the baby’s shoulders and buttock.  Do not flex the neck.  (The baby may develop apnoea).
• Preparing the insertion area with hibitane and alcohol and iodine and sterile drapes.
• Insert the needle between the 4^th and 5^th lumbar spinous (directly in line with the iliac cristae processes).
• CSF is now collected in 2 tubes (0.5 - 1 ml each for micro and chemistry) and 1 fluoride tube (for glucose determination).
• If insufficient volume of CSF is collected ask only for cell counts and MCS determinations.

Precautions

1.  Do not attempt the LP above the level of L3/L4.  The neonatal spinal cord extends to L3.
2.  Insert the spinal needle and advance carefully into the intraspinous space.  Do not advance to deeply.  The anterior vertebral plexus can be penetrated and this results in a bloody CSF tap.
3.  In cases where the infant is very ill, it is sometimes better to wait until the clinical circumstances improve.
4.  Do not attempt the procedure repeatedly if the LP is initially unsuccessful.
5.  If a bloody CSF tap is obtained, spin the CSF down and observe the supernatant.  
   If it is xanthochromic an intaventricular or subarachnoid haemorrhage should be suspected.
6.  Always do a concomitant blood glucose so as to compare with the CSF glucose (fluoride tube).

Discuss the desirability of local anaesthesia in each case with the consultant concerned.