At what level lumbar puncture is done and why?
Therefore a lumbar puncture is generally performed at or below the L3-L4 interspace. As a general anatomical rule, the line drawn between the posterior iliac crests often corresponds closely to the level of L3-L4. The interspace is selected after palpation of the spinous processes at each lumbar level.
Why is a lumbar puncture done between L3 and L4?
Since the spinal cord ends as a solid structure around the level of the second lumbar vertebra (L2) the insertion of a needle must be below this point, usually between L3 and L4 (Fig 2). The spinal cord continues below L2 down into the sacrum as many separate strands of nerve pathways, the cordae equina, bathed in CSF.
How do you calculate L4 L5?
Wearing nonsterile gloves, locate the L3-L4 interspace by palpating the right and left posterior superior iliac crests and moving the fingers medially toward the spine (see the image below). Palpate that interspace (L3-L4), the interspace above (L2-L3), and the interspace below (L4-L5) to find the widest space.
What are the contraindications of lumbar puncture?
Absolute contraindications for performing a LP include infected skin over the puncture site, increased intracranial pressure (ICP) from any space-occupying lesion (mass, abscess), and trauma or mass to lumbar vertebrae.
Which is the best way to position a patient for lumbar puncture?
Positioning — An LP can be performed with the patient in the lateral recumbent or prone positions or sitting upright. The lateral recumbent or prone positions are preferred over the upright position because they allow more accurate measurement of the opening pressure.
When should you not have a lumbar puncture?
Avoid lumbar puncture in patients in whom the disease process has progressed to the neurologic findings associated with impending cerebral herniation (ie, deteriorating level of consciousness and brainstem signs that include pupillary changes, posturing, irregular respirations, and very recent seizure)
How long do you have to lay flat after a lumbar puncture?
The blood is put through a need into your spinal canal in the same way that the LP was done. You will need to lie in bed for 1 to 2 hours after this procedure.