Provide initial anesthesia/analgesia (e.g., lidocaine cream), anxiolysis or sedation as needed
Appropriately position the patient in either lateral decubitus position or sitting. Generally, the lateral decubitus position is preferred, if measuring an opening pressure or patient is unable to sit. Have the patient arch their back.
Identify and mark anatomic landmarks. The L4 spinous process is at the level of the posterior superior iliac crests.
Prepare the skin with antiseptic solution.
Put on sterile gloves, then apply the sterile drape.
Create a wheal with local anesthetic in the skin overlying the entry site. Remember to aspirate before injecting anesthetic. Then, infiltrate and anesthetize the deeper tissues.
Insert spinal needle with stylet in the midline with bevel facing the ceiling. Hold needle parallel to the bed and advance toward the umbilicus. Remove the stylet periodically to check for CSF.
Advance spinal needle until CSF noted in hub of needle.
If measuring the opening pressure, attach the manometer.
Collect an appropriate amount of CSF in sequential, numbered vials
Replace stylet and remove the needle. Apply pressure at insertion site with gauze.
Clean skin and apply dressing.
Instruct patient to lie flat on their back for 30 minutes to 1 hours after the procedure.