Lumbar puncture

Disclaimer These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline.  Read the full CAHS Emergency Department disclaimer

Aim

To guide staff in performing lumbar puncture (LP) in children and to:

1. Ensure the safety and comfort of the infant or child/adolescent whilst obtaining a cerebrospinal fluid (CSF) sample.
2. Measure opening pressure, if required and collection of an adequate and appropriate CSF sample to enable the diagnosis of central nervous system infections, inflammation and metabolic disorders without contaminating the specimen.
3. Safely and timely transport the specimen to the laboratory.

Pre-procedure

• Patients who require a lumbar puncture (LP) must be discussed with an ED Consultant or Senior Doctor before commencing the procedure
• A lumbar puncture should never delay potentially life saving interventions such as the administration of antibiotics to patients with suspected bacterial or viral meningitis
• Informed verbal consent is required prior to commencement of an LP. This should include discussion and explanations about the diagnostic (and potentially therapeutic benefits) benefits of the procedure and the potential complications.
• A Lumbar puncture - Health Facts sheet (PDF) should be provided to parents to assist with consent and education.

General¹

• LP is a procedure performed to obtain a cerebral spinal fluid (CSF) sample.
• LP must be undertaken with strict adherence to aseptic technique.
  • For comparison with CSF glucose a capillary/venous blood glucose level (BGL) should be obtained immediately before the procedure.
• An LP is performed only after a thorough examination which focuses on detecting signs of raised intracranial pressure (ICP).
• A normal CT (Computerised Tomography) scan does not exclude raised ICP and is not a substitute for a thorough examination.
• Difficult LP - where a non-urgent lumbar puncture is anticipated to be difficult (e.g. patient body mass index > 30), consideration should be given at the outset as to whether the procedure should be deferred and performed under image guidance and/or general anaesthesia.
• After two unsuccessful attempts at LP, 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.
• If the fluid obtained is likely to be blood and not blood-stained CSF, a senior clinician should decide whether the procedure should be deferred, and empiric therapy commenced.
• For therapeutic lumbar puncture with intrathecal chemotherapy administration, refer to the Oncology Department.

Indications

• Suspected meningitis or encephalitis
• Suspected sub-arachnoid haemorrhage with a normal CT
• Measurement of opening pressure in suspected idiopathic intracranial hypertension
• Therapeutic reduction in ICP in idiopathic intracranial hypertension
• To assist with the diagnostic assessment of neuroinflammatory disorders such as acute disseminated encephalomyelitis (ADEM), transverse myelitis and Guillain-Barre Syndrome (GBS), and neurometabolic conditions.

Contraindications⁵

• Coma or decreased conscious state: absent / non-purposeful response to painful stimuli.
• Signs of raised intracranial pressure (ICP):
  • Altered pupillary responses
  • Absent doll’s eye reflexes
  • Decerebrate or decorticate posturing
  • Papilloedema
  • Abnormal respiratory pattern, hypertension, bradycardia (Cushing's triad).
• Within 30 minutes of seizure or if normal conscious level has not returned post seizure.
• New focal neurological signs - hemiparesis, extensor plantar responses, ocular palsies.
• Strong suspicion of meningococcal infection with risk of disseminated intravascular coagulation (typical purpuric rash in an unwell child).
• Local infection at the needle insertion site.
• Known or suspected coagulation defects.
• Cardiovascular compromise/shock.
• Respiratory compromise e.g. baby with apnoeas.
• Thrombocytopaenia: If platelets < 50x109/L discuss with Consultant (or <100x109/L in oncology patients).

Preparation

Staff

• Doctor performing the LP.
• One to two assistants will be required to assist with appropriate positioning, holding of the patient and preparing the equipment – at least one should be a nurse / doctor experienced in clinical positioning for a LP.

Equipment

• Dressing trolley
• Large dressing pack.
• Sterile: gown, gloves, hand towel, fenestrated drape, gauze.
• Appropriate skin antiseptic:
  • Infants, children, adolescents: chlorhexidine 2% & isopropyl alcohol 70% (e.g. Maxi swabstick) or
  • Povidone iodine 10% if known sensitivity to chlorhexidine
  • Neonates ≥ 28 weeks gestation: chlorhexidine 1% & isopropyl alcohol 70% (swab stick preferable)
  • Preterm neonates < 28 weeks gestation: povidone iodine 10% solution.
• 3 sterile CSF specimen containers.
  • More than 3 containers may be required if multiple tests are required on the CSF sample. 
  • Minimum required volumes for each test are indicated in the PathWest test directory. Discuss with the Clinical Microbiologist prior to sample collection, if necessary.
• Small transparent, semi permeable, occlusive dressing.
• Spinal lumbar puncture needles (length depends on age).
• 22G or 25G bevelled spinal tap 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.

Illustration of equipment only, not 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
• Manometer set.

Procedural sedation and analgesia

• Topical anaesthetic creams (e.g. lidocaine (lignocaine) 2.5% with prilocaine 2.5% (EMLA®) ) may be applied in the setting of non-urgent or planned LPs. Apply to the planned LP site and cover with occlusive dressing for 45-60 minutes.
• During the procedure options are:
  • Local anaesthetic lidocaine (lignocaine) 1% infiltration
  • Oral sucrose for infants < 3 months old
  • Nitrous oxide sedation for children older than 3 years with a normal conscious state
  • Procedural Sedation - Clinical Practice Manual (internal WA Health only) may be considered
  • Non-pharmacological techniques
  • Distraction, parental presence

Monitoring

• All seriously ill children require continuous pulse oximetry monitoring
• Consider cardiac monitoring where appropriate
• When sedation has been used follow the relevant protocol / guideline
• A minimum of hourly neurological observations for 4 hours for all patients post procedure (may require longer depending on underlying illness)

Procedure

1. Prepare the trolley

• Perform hand hygiene.
• Decontaminate dressing trolley with a detergent wipe and allow it to dry prior to procedure set up.
• Open sterile equipment onto sterile field.

2. Position of patient

• Perform hand hygiene before touching the patient.
• Appropriate positioning increases the interspinous distance, facilitating access to meninges and CSF.
  
  • Position the patient in a lateral position with the patient facing the positioning nurse
  • Patient knees and chin are to be drawn to the chest, and body well flexed (foetal position)
  • The hips should be vertical to align the iliac crests i.e. back should be 90 degrees to the bed
  • The patients back should be positioned parallel and close to the edge of the bed.

Alternatively

• Older patients may prefer to remain in a sitting position. Have the patient slouch shoulders over a pillow without bending at the hips and maintaining the 90 degree back to bed position.
• Avoid over flexion of the neck, especially in infants as respiratory compromise may result.

3. Preparation

• Perform hand hygiene (Moment 1) before touching the patient.
• Identify the LP site – a line between the top of the iliac crest intersects the spine at approximately the L3/L4 interspace:
  • Site for needle insertion should be L3/L4 or L4/L5 interspace.
• Wash hands using aseptic technique and put on sterile gown, gloves and mask.
• Prepare skin with antiseptic swab sticks or sterile forceps and gauze:
  • Wipe antiseptic swab in a circular motion commencing at the proposed insertion site
  • Repeat with second swab stick or sterile forceps and gauze.
• Drape the patient with the fenestrated sterile drape ensuring the airway is visible at all times.
• Remove caps from the CSF specimen containers.  Mark the containers 1,2,3 if marker pen is included in sterile pack (optional).
• Identify the landmarks and palpate the needle insertion point.
• If using local anaesthetic:
  • Infiltrate the skin with lidocaine (lignocaine)1% (allow 1-2 minutes for anaesthetic effects).
• Ensure the skin is dry prior to the needle insertion.
• Reconfirm the land marks and LP site prior to the needle insertion.

4. Spinal needle insertion

• Hold the spinal needle so that bevel is in the superior position (facing up)
• With the stylet in position, insert the needle through the skin and wait for any patient movement to stop
• Aiming for the umbilicus, advance the needle in the direction towards patient’s umbilicus until there is a decrease in resistance.

• Remove the stylet and check for CSF appearing at the needle hub:
• If CSF is not flowing:
  • Replace stylet fully and advance or reposition the needle slightly and recheck for CSF as above.
• If CSF is flowing
  • If opening pressure measurement is required, connect manometer to spinal needle.
  • Collect 10 drops in each (x3) sterile container (note which container holds the first collection).
  • Minimum required volumes for each test are indicated in the PathWest test directory. Discuss with the Clinical Microbiologist prior to sample collection, if necessary.
• When sample collection is complete, reinsert the stylet
• Remove the needle and stylet as one
• 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).

Specimens

• Label the CSF containers with the patient’s name, date of birth, UMRN and date and time of specimen collection.
• Complete pathology request form ensuring the patient details (name, date of birth and UMRN) match those given on the specimen containers. Specify the required investigations which commonly include:
  • CSF Microscopy, culture and susceptibility testing (M,C&S)
  • CSF protein and glucose (ensure a blood glucose result is available from approximately the time of CSF collection)
  • A multiplex polymerase chain reaction (PCR) panel will be routinely performed on:
    • all CSF samples from all infants < 28 days
    • all CSF samples where the total white cell count is > 5 cells per mm3
    • other CSF samples on request where the clinical suspicion of meningitis is high
• The BioFire® FilmArray® Meningitis/Encephalitis (ME) Panel is a multiplex PCR panel used to identify multiple viral and bacterial pathogens. Pathogens detected by this panel include:
  • Bacteria: Escherichia coli K1; Haemophilus influenzae; Listeria monocytogenes; Neisseria meningitidis; Streptococcus agalactiae; Streptococcus pneumoniae
  • Viruses: Cytomegalovirus (CMV). Enterovirus (EV), Herpes Simplex Virus 1 and 2 (HSV-1; HSV-2); Human Herpesvirus 6 (HHV-6); Human Parechovirus (HPeV), Varicella Zoster Virus (VZV)
  • Fungi: Cryptococus neoformans/gattii
• Place labelled containers in a biohazard bag and send to the laboratory with the completed pathology request form via a patient support assistant (PSA).
• Liaise with the laboratory if other organisms are suspected, or if Gram stain and the BioFire ® result are negative when the CSF white cell count (WCC) suggests meningitis. This will allow testing for organisms not in the BioFire ® ME panel, or use of more sensitive targeted PCRs.
• CSF cell count and culture set-up will be performed urgently.
• Document the following in patient’s notes:
  • date and time of sampling
  • name of the doctor who performed LP
  • gauge of LP needle used
  • number of attempts; 'first/second pass'
  • space entered
  • CSF appearance (i.e. clear and colourless, turbid, or bloodstained)
  • reason for CSF sampling
  • signature.

Post Procedure

Complications

• Headaches ^2,4 (common, up to 15%)
• Backaches
• Transient / persistent paraesthesia / numbness
• Cerebral herniation ( bradycardia, apnoeas, oxygen desaturations)
• Subdural haemorrhage
• Spinal epidural haemorrhage
• Paraplegia
• Infection (local and introduction into CSF spaces)
• Cardiorespiratory compromise due to positioning
• Spinal epidermoid tumours associated with needles without a stylet (rare) 

Aftercare

• A minimum of hourly neurological observations are required for all patients post procedure, including checking of LP site.
• 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 It is reasonable to encourage rest and avoid strenuous activity for the remainder of the day.
• Patients should be allowed to mobilise as soon as it is safe to do so and, if applicable, on recovering from sedating medication.

CSF Interpretation¹

• Normal CSF should not contain neutrophils but may have variable WBC depending on age.

	Neutrophils	Lymphocytes	Protein	Glucose
Normal term neonate	0	< 20	< 1g/L	> 2/3 serum glucose or > 2.0mmol.L
Normal (> 1 month of age)	0	< 5	< 0.4g/L	>2/3 serum glucose or > 2.5mmol/L
Abnormal results
Bacterial meningitis	Very high	Usually < 100	> 1g/L	Low
Viral meningitis	Usually < 100	10-1000	Normal	Normal
Partially treated	See below
Blood stained sample	See below

• Partially treated bacterial meningitis may have a CSF picture of bacterial meningitis, viral meningitis or a combination of both.
• Blood stained CSF from a traumatic procedure can be more difficult to interpret. A discussion with a Clinical Microbiologist or Infectious Diseases Physician is recommended

Antimicrobial therapy

If the lumbar puncture has been performed because central nervous system infection is thought possible or likely, empiric antimicrobial therapy should be commenced immediately.

Refer to Meningitis and Meningoencephalitis – ChAMP Guidelines for guidance.

References

1. Bonadio W. Pediatric Lumbar Puncture and Cerebrospinal Fluid Analysis. J Emerg Med 2014; 46: 141-150
2. 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.
3. 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.
4. 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.
5. UpToDate. Fastle & Bothner Lumbar puncture: Indications, contraindications, technique, and complications in children Oct 2020/ Lumbar puncture: Indications, contraindications, technique, and complications in children - UpToDate (health.wa.gov.au) Lumbar puncture: Indications, contraindications, technique, and complications in children - UpToDate (health.wa.gov.au)

Endorsed by:	Co-Director, Surgical Services	Date:	Sep 2022
		Review date:	Oct 2025

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