Paeds · investigations-procedures-and-technology
Lumbar puncture in infants and children
Also known as Lumbar puncture · LP · Spinal tap · Paediatric CSF sampling · Cerebrospinal fluid analysis · Intrathecal access
Fellowship guide to lumbar puncture in infants and children. Covers the indications, the absolute contraindications of raised intracranial pressure, coagulopathy, overlying skin infection and the unstable child, the indications for CT before LP, why the infant spinal cord ends at L3 and the safe interspaces this dictates, the lateral decubitus and sitting positions and why opening pressure is reliable only in a calm child in the lateral decubitus position, the atraumatic pencil-point needle and its reduction of post-dural puncture headache, the normal CSF values and the traumatic-tap correction, the topical, local and procedural-sedation analgesia options, the common and serious complications, and the ANZ, UK and North American guideline differences on antibiotics-first in suspected meningitis.
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Red flags
- A child with raised intracranial pressure, papilloedema, focal neurology, a decreased conscious state or a prolonged postictal state in whom an LP is attempted without a CT head first — the sudden release of CSF pressure below the constriction precipitates cerebral herniation and death
- A child with uncorrected coagulopathy, a platelet count under 50 × 10⁹ per litre, or an INR over 1.5 in whom LP is attempted — the procedure can produce a spinal epidural haematoma that compresses the cord and causes permanent paraplegia
- An overlying skin infection at the puncture site — the needle can seed skin flora into the subarachnoid space and cause iatrogenic bacterial meningitis or an epidural abscess
- A septic-shocked or comatose child in whom LP is pursued before resuscitation and empirical antibiotics — the delay kills, and the LP can usually be deferred safely until the child stabilises
- An opening pressure quoted from a sitting position, or from a crying, breath-holding or straining child — the value is unreliable and must not be used to diagnose or exclude raised intracranial pressure
- Omitting analgesia in a child old enough to feel the procedure — lumbar puncture hurts, and untreated procedural pain is both an unnecessary harm and a cause of a failed or traumatic tap
Life stages
Care settings
Clinical exam formats
Board mappings
- Procedures and investigations
- Perform and supervise a lumbar puncture in an infant or child
- Recognition of contraindications and when to image before lumbar puncture
- Current 2026 PREP curriculum — Learning goal 11: Investigations and procedures
- Renewed curriculum for first-year trainees from 2027 — Learning goal 11: Investigations and procedures
- Safe performance and supervision of paediatric lumbar puncture
- Written Examination
- Clinical Applications
- Infectious diseases and neurological emergencies requiring LP
- Short Cases
- Procedural skills and consent
- Communication and patient-safety scenarios
- 11. Investigating and managing paediatric presentations
- Level 2: Performs common paediatric procedures including lumbar puncture with appropriate supervision
- Patient safety: recognising contraindications and when to image before LP
- Applied Knowledge in Practice (AKP)
- Foundations of Practice (FOP)
- Procedures: indications, contraindications and complications of LP
- Clinical
- Communication scenarios
- Safe procedural skills and consent
- General Pediatrics Content Outline — Procedural skills: lumbar puncture
- General Pediatrics Content Outline — Infectious diseases and neurologic emergencies
- General Pediatrics EPA: Perform a lumbar puncture in an infant or child
- Patient Care 3: Procedural skills
- Medical Knowledge 1: Clinical knowledge
- Systems-Based Practice: safe procedural practice and consent
- Medical Expert
- Communicator
- Pediatrics: Core EPA — Perform a lumbar puncture in an infant or child
Overview & Definition
Picture the eight-month-old febrile, irritable infant with a bulging fontanelle, or the four-year-old who has had a brief generalised seizure with fever and now looks septic. In both, question team must answer is whether there is infection or inflammation in the subarachnoid space — and the only way to answer it reliably is to sample the cerebrospinal fluid by lumbar puncture. That is the territory this page owns. [1] [10]
A lumbar puncture (LP) is the percutaneous passage of a fine, hollow, styletted needle through the skin, supraspinous and interspinous ligaments, ligamentum flavum, dura mater and arachnoid into the lumbar subarachnoid space, below the level where the spinal cord ends, to sample cerebrospinal fluid, measure its pressure, or deliver a drug. The core diagnostic use is suspected meningitis or encephalitis; the other common indications include the septic workup of the young febrile infant, unexplained altered conscious state, suspected idiopathic intracranial hypertension, the staging and intrathecal treatment of leukaemia, and a small number of therapeutic indications such as the removal of CSF in normal-pressure or idiopathic intracranial hypertension. [1] [9]
What makes paediatric LP a distinct skill from adult LP is anatomy that changes with age and a child who cannot be reasoned into holding still. The infant's spinal cord ends lower than the adult's, the dural sac ends lower, the needle and the dose of local anaesthetic must be scaled to the child, and the procedure demands genuine analgesia and often procedural sedation. The fellowship skill being tested is reading the child, choosing the right indication, screening out the contraindications, and performing a calm single-pass procedure that yields diagnostic CSF and a reliable opening pressure without harm. [1] [12]
References12ShowHide
- [1]Schulga P, Grattan R, Napier C, et al. How to use… lumbar puncture in children Arch Dis Child Educ Pract Ed, 2015.PMID 26104280
- [2]Rao S Atraumatic lumbar puncture needles are associated with fewer complications than conventional needles Arch Dis Child Educ Pract Ed, 2019.PMID 30368456
- [3]Alcock A, Salter R Towards evidence-based emergency medicine: best BETs from the Manchester Royal Infirmary. BET 2: what gauge and type of lumbar puncture needle should we be using in the paediatric population to reduce the risk of postdural puncture headaches? Emerg Med J, 2013.PMID 23275464
- [4]Bandatmakur M, Bench C, Ngwa N, et al. Factors Predisposing to Post Dural Puncture Headache in Children J Child Neurol, 2021.PMID 33882752
- [5]Janssens E, Aerssens P, Alliët P, et al. Post-dural puncture headaches in children. A literature review Eur J Pediatr, 2003.PMID 12655411
- [6]Cartwright C, Igbaseimokumo U Lumbar puncture opening pressure is not a reliable measure of intracranial pressure in children J Child Neurol, 2015.PMID 24799366
- [7]Summers AE, Wilson JL Opening Pressure and Post-Lumbar Puncture Headache in Children Undergoing Intrathecal Baclofen Trial J Child Neurol, 2024.PMID 38419482
- [8]Koch BL, Moosbrugger EA, Egelhoff JC Symptomatic spinal epidural collections after lumbar puncture in children. AJNR Am J Neuroradiol, 2007.PMID 17885251
- [9]Williams J, Lye DC, Umapathi T Diagnostic lumbar puncture: minimizing complications Intern Med J, 2008.PMID 18422562
- [10]Visintin C, Mugglestone MA, Fields EJ, et al. Management of bacterial meningitis and meningococcal septicaemia in children and young people: summary of NICE guidance BMJ, 2010.PMID 20584794
- [11]Burstein B, Waterfield T, Umana E, et al. Prediction of Bacteremia and Bacterial Meningitis Among Febrile Infants Aged 28 Days or Younger JAMA, 2026.PMID 41359314
- [12]Pessano S, Romantsik O, Olsson E, et al. Pharmacological interventions for the management of pain and discomfort during lumbar puncture in newborn infants Cochrane Database Syst Rev, 2023.PMID 37767875