From the Guidelines
Lumbar puncture is indicated for several clinical scenarios where examination of cerebrospinal fluid (CSF) is necessary for diagnosis or treatment, including suspected central nervous system infections, subarachnoid hemorrhage, inflammatory conditions, and certain cancers involving the central nervous system. The primary indications for lumbar puncture include:
- Suspected central nervous system infections such as meningitis or encephalitis
- Subarachnoid hemorrhage not detected by imaging
- Inflammatory conditions like multiple sclerosis
- Idiopathic intracranial hypertension requiring pressure measurement or therapeutic drainage
- Certain cancers involving the central nervous system
- Administration of intrathecal medications or contrast agents for diagnostic procedures
Before performing a lumbar puncture, clinicians should check for contraindications such as:
- Increased intracranial pressure
- Infection at the puncture site
- Coagulopathy
- Spinal cord compression
- Platelet count < 100 109/L
- Anticoagulant therapy
The procedure involves inserting a needle between the L3-L4 or L4-L5 vertebral interspaces to access the subarachnoid space, with the patient typically positioned in lateral recumbency with knees drawn to chest 1. CSF analysis typically includes measuring opening pressure, cell count, protein and glucose levels, cultures, and specialized tests depending on the suspected diagnosis. This invasive procedure should only be performed when the diagnostic or therapeutic benefits outweigh the risks of complications such as post-dural puncture headache, bleeding, or infection 1.
It is essential to weigh the benefits and risks of the procedure, considering the patient's individual circumstances and the potential consequences of not performing the lumbar puncture 1. The use of atraumatic needles and careful patient selection can minimize the risk of complications 1. Ultimately, the decision to perform a lumbar puncture should be based on a thorough evaluation of the patient's condition and the potential benefits of the procedure.
From the Research
Indications for Lumbar Puncture
The indications for a lumbar puncture (LP) can be summarized as follows:
- Diagnostic indications:
- Therapeutic indications:
Specific Clinical Scenarios
Lumbar puncture is frequently performed in the Emergency Department for suspicion of CNS infection, which is eventually confirmed in one third of cases 3. It is also indicated when CNS infection is suspected or to establish the diagnosis of subarachnoid hemorrhage when results of cranial computed tomography are normal 4. Additionally, lumbar puncture can be used to infuse medications in the subdural space, such as epidural steroids for severe inflammatory lower back pain 5.
Important Considerations
It is essential to note that lumbar puncture should only be performed by a healthcare professional who is familiar with the contraindications, regional anatomy, and technique used to perform it 2, 6, 4. Proper evaluation of the patient's medical condition and blood studies should be performed prior to lumbar punctures to avoid major morbidities 5.