To guide staff in performing lumbar puncture in children and to:
Ensure the safety and comfort of the infant or child whilst obtaining a cerebrospinal fluid (CSF) sample.
Collect an adequate CSF sample to enable the diagnosis of central nervous system infections, inflammation and metabolic disorders without contaminating the specimen.
Failure to follow this guideline may lead to:
Complications associated with lumbar punctures due to incorrect procedure or patient selection.
Increased risk of CSF sample contamination which may lead to a child receiving unnecessary antimicrobial therapy.
Patients who require a lumbar puncture (LP) must be discussed with a Consultant or Senior Doctor before commencing the procedure.
A lumbar puncture should never delay potentially lifesaving interventions such as the administration of antibiotics to patients with suspected bacterial meningitis.
Informed verbal consent from patient and parent/guardian is required prior to commencement of an LP and should be documented in the patient record. This should include discussion and explanations about the diagnostic benefits of the procedure and the potential complications.
A lumbar puncture health fact sheet should be provided to parents to assist with consent and education.
Lumbar puncture is the procedure used to obtain cerebral spinal fluid (CSF)
For comparison with CSF glucose a BGL should be obtained immediately before the procedure
An LP is only conducted after a thorough neurological examination and raised intracranial pressure (ICP) or other contraindications have been excluded.
A normal CT scan does not exclude raised ICP and is not a substitute for a thorough examination.
Difficult LP – where a non-urgent lumbar puncture is perceived to be difficult (e.g. patient body mass index > 30), consideration should be given at the outset as to whether the procedure would be better performed under image guidance.
If a lumbar puncture is attempted unsuccessfully on two occasions, the patient should be referred to a more senior clinician to either perform the procedure or refer for it to be done under image guidance
For therapeutic lumbar puncture with intrathecal chemotherapy administration, refer to the Department of Oncology guidelines
Suspected meningitis or encephalitis
Suspected sub-arachnoid haemorrhage with a normal CT
Measurement of opening pressure in suspected benign intracranial hypertension
Therapeutic reduction in ICP in benign intracranial hypertension
Disease staging and instillation of chemotherapy in oncology patients
To assist with the diagnosis of other central nervous system pathologies including demyelinating, neuroinflammatory and neurometabolic conditions.
Coma or decreased conscious state: absent/non-purposeful response to painful stimuli
Small transparent, semi permeable, occlusive dressing.
Spinal lumbar puncture needles (length depends on age).
22G or 25G bevelled spinal needles with stylet. Needle length and gauge depend on the age and size of the child and the indication for lumbar puncture. Pencil point is preferred in older children to reduced risk of headache.
Picture for illustration of equipment only – this is not an aseptic set up.
Additional equipment that may be required:
Local anaesthetic, 2ml / 5ml syringe, needles
Surgical face mask (in peri-operative environment or for intrathecal chemotherapy)
Protective eye goggles
Procedural Sedation and Analgesia
Apply topical anaesthetic cream (e.g. EMLA) to insertion site and cover with occlusive dressing for 45-60 minutes (except where specimens are urgent)
During the procedure options are:
Local anaesthetic (1% lignocaine) infiltration
Oral sucrose for infants < 3 months old
Nitrous oxide for children older than 3 years with a normal conscious state
When sample collection is complete, reinsert the stylet
Remove the needle and stylet
Use sterile gauze to apply gentle pressure to the insertion site
Cover the insertion site with a transparent occlusive dressing (e.g. Tegaderm), which should remain in situ for 24 hours
Remove personal protective equipment and perform hand hygiene (Moment 3)
Label the CSF containers with the patient’s name, date of birth, UMRN and date and time of specimen collection.
Place labelled containers in a biohazard bag and send urgently to the laboratory for cell count, protein, glucose, microscopy and culture. CSF PCR (herpes simplex, enterovirus etc should be requested as indicated).
If specimen collection occurs outside of laboratory opening hours, contact the on-call microbiology scientist via switchboard to perform an urgent microscopy.
Failure to obtain specimen, repeated attempts (common)
Headaches2,4 (common, up to 15%)
Transient/ persistent paraesthesiae/ numbness
Intracranial subdural haemorrhage
Spinal epidural haemorrhage
Cardiorespiratory compromise due to positioning
Spinal epidermoid tumours associated with needles without a stylet (rare)
A minimum of hourly neurological observations are required for all patients post procedure, including checking of LP site
Routine bed rest after a lumbar puncture is not required2, and patients should be allowed to mobilise as soon as it is safe to do so and, if applicable, recovered from sedating medication.
All CSF should be sent for urgent cell count, protein, glucose, microscopy and culture.
Normal CSF should not contain neutrophils but may have variable WBC depending on age.
The table below can be used as a guide for CSF interpretation:
Normal Term Neonate
>2/3 Serum glucose or >2.0mmol/L
Normal (>1 month age)
>2/3 Serum glucose or >2.5mmol/L
Partially treated bacterial meningitis may have a CSF picture of bacterial meningitis, viral meninigitis or a combination of both.
Blood stained CSF from a traumatic procedure can be more difficult to interpret.
There are various methods to calculate whether WCC is significant in a traumatic tap:
A ratio of 1 WBC to 750 RBC in CSF is normal if a patient’s FBC is normal
A calculation may be used to correct CSF WBC counts which are falsely increased due to a traumatic tap:
WBCs added = WBC(blood) x RBC(CSF) / RBC(blood)
Current available evidence does not support bed rest over immediate mobilisation in the reduction of postural headaches; therefore routine bed rest is not required.2-4
Arevalo-Rodriguez I, Ciapponi A, Roqué i Figuls M, Muñoz L & Bonfill Cosp X. Posture and fluids for preventing post-dural puncture headache. Cochrane Database of Systematic Reviews 2016, Issue 3. Art. No.: CD009199. DOI: 10.1002/14651858.CD009199.pub3.
Evans RW, Armon C, Frohman EM & Goodin DS. Assessment: prevention of post-lumbar puncture headaches. Report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology 2000; 55(7): 909-14.
E, Aerssens P, Alliet P, Gillis P & Raes M. Post-dural puncture headaches in children. A literature review. European Journal of Pediatrics 2003; 162: 117-21.
Endorsed by Clinical Practice Advisory Committee November 2017