Appropriate for infants, children, and adults.Advantage: easier to identify midline and maintain the correct needle trajectory.To keep the spinal cord alive, insert the needle between 元 and L5. Easiest to identify when the patient is upright.Typically at the intersection of a line connecting the posterior iliac crests and a line connecting the spinous processes.Midline: identified by palpation of the spinous processes.In adults, lumbar puncture is most commonly performed in the midline of the 元-L4 or L4-L5 interspace. We list the most important contraindications. Infection at the procedure site: e.g., cellulitis, abscess.

Consider anticoagulant reversal if LP is needed urgently.

See “ Periprocedural management of DOAC therapy” for details.

Length of delay depends on the agent and patient renal function.

Low-molecular-weight heparin: 12–24 hours after last dose.

Unfractionated IV heparin: 4–6 hours after last dose.

NSAIDs (including aspirin): no delay required.

Consider correction if platelet count 1.5.

Increased risk of epidural hematoma and spinal cord compression.

↑ ICP: Consider specialist consultation for the management of elevated ICP prior to LP.

Obtain head CT if criteria for imaging prior to LP are present.

E.g., due to space-occupying lesion with mass effect or posterior fossa mass.

Prior to LP, an effort should be made to identify potential contraindications and reduce patient risk. Pharmacologic or interventional management may be necessary. The severity of post-lumbar puncture headache ranges from mild to incapacitating. Post-lumbar puncture headache is a common complication, especially in young women, and is often accompanied by nausea and visual changes. CNS imaging and/or correction of coagulopathies should be considered prior to performing a lumbar puncture if the risk caused by procedural delay is acceptable. Untreated elevated intracranial pressure, bleeding disorders, and spinal abscesses are contraindications to lumbar puncture. Drainage of CSF is used in the treatment of idiopathic intracranial hypertension and normal pressure hydrocephalus. CSF analysis may aid in the diagnosis of meningitis, intracranial hemorrhage, multiple sclerosis, and meningeal carcinomatosis. Additional tubes (enough to contain 30 to 40 mL of CSF) may also be needed if a high-volume LP is planned for diagnosis of normal pressure hydrocephalus.Lumbar puncture ( LP) is a diagnostic and/or therapeutic procedure in which a spinal needle is passed into the subarachnoid space and cerebrospinal fluid ( CSF) is removed, CSF opening pressure is measured, and/or medications are injected. read more ) or carcinomatous meningitis are suspected. Possible causes include fungi, Mycobacterium tuberculosis, rickettsiae, spirochetes, Toxoplasma. read more or fungal meningitis Fungal meningitis that develops after epidural methylprednisolone injection Subacute meningitis develops over days to a few weeks. read more (eg, tuberculous Tuberculous meningitis Subacute meningitis develops over days to a few weeks.

Large volumes of 30 to 40 mL of CSF may need to be collected where chronic meningitis Subacute and Chronic Meningitis Subacute meningitis develops over days to a few weeks. 4 CSF collection tubes (labeled 1 through 4) for laboratory studies additional tubes if large-volume CSF collection is needed (eg, 30 to 40 mL) or additional special tests are needed.