• Knowledge of the anatomy and physiology of the vertebral column, spinal meninges, spinal cord, nerve roots, and cerebrospinal fluid (CSF) circulation and intracranial and intraspinal dynamics is needed.

• Knowledge of aseptic technique is necessary.

• Normal intraspinal pressure in the adult is 0 to 20 cm H₂O (0 to 15 mm Hg or 50 to 150 mm H₂O) and usually corresponds with intracranial pressure.²⁴ Intraspinal pressure may be influenced by a number of factors. Further research is needed to ascertain therapeutic levels after various surgical interventions.²¹

• Lumbar subarachnoid catheters, also referred to as lumbar drains or intrathecal catheters, require lumbar puncture (LP) for insertion.¹⁶ Lumbar subarachnoid catheters permit monitoring of CSF pressure. CSF pressure may be monitored intermittently or continuously, and CSF drainage may be performed intermittently or continuously.^23,40

• Lumbar subarachnoid catheters may be used in the prevention or management of spontaneous, traumatic, or surgical CSF fistulas to allow any tears in the dura mater to heal.37,41–44 The catheter reduces moisture and pressure at the tear and may be placed before, during, or after surgery.^4,8,11,37,41

• Lumbar subarachnoid catheters may be used in the diagnostic workup and management of normal pressure hydrocephalus instead of serial lumbar punctures.^12,27,28

• Lumbar subarachnoid catheters may be used in the perioperative management of intraspinal pressure during and after thoracoabdominal aortic aneurysmal repair to provide adequate room in the intraspinal space to accommodate spinal cord edema and to improve impaired spinal cord perfusion related to spinal cord edema.

• Lumbar subarachnoid catheters may be used instead of or with an external ventricular drain to decrease intracranial pressure and remove blood from the subarachnoid space, which may lessen aneurysmal subarachnoid hemorrhage vasospasm.^{13,16,22,26,36} When ventricular and lumbar drainage are used simultaneously, the ventricular drainage output should exceed the lumbar drainage output to lessen the risk of herniation.^12,16,22,38

• Lumbar subarachnoid catheters may be use in the management of communicating hydrocephalus related to intraventricular, intracerebral hemorrhage.^18,19

• Complications related to the use of lumbar subarachnoid catheters include infection, headache, nerve root irritation, retained fragments of broken catheters, paraplegia, and neurologic deterioration related to overdrainage, including subdural hematomas, pneumocephalus, and herniation.^1,30,31,33

• Lumbar subarachnoid catheters have been used, with extreme caution, in the management of patients with meningitis.²⁶

• Lumbar subarachnoid catheter drainage is contraindicated with midline mass effect. A computed tomographic (CT) scan before lumbar subarachnoid catheter insertion to confirm discernible basal cisterns and absence of a mass lesion may lessen the risk of herniation.^1,16,21,22

• A variety of products are available for lumbar subarachnoid catheter drainage systems, making it essential to follow the manufacturer’s guidelines for management of the patient²³ to include the type of pressure measurement unit used for patient monitoring (e.g. monitoring pressures in units mm Hg, cm H₂O).

• Antiseptic solution

• Caps, masks with face shields, sterile gowns, and sterile gloves

• Sterile towels, half-sheets, and drapes

• Local anesthetic (lidocaine 1% or 2% without epinephrine)

• 5- or 10-mL Luer-Lok syringe with 18-gauge needle for drawing of lidocaine and 23-gauge needle for administration of lidocaine

• Sutures (2-0 nylon, 3-0 silk)

• Forceps

• Sterile scissors

• Sterile needle holder

• Preservative-free sterile normal saline solution (vial, bag, or prefilled syringe)

• Lumbar catheter tray

• Lumbar puncture tray

• Sterile occlusive dressing

• Tape (1- and 2-inch rolls)

• External transducer with three-way stopcock

• Pressure cable

• External CSF drainage system

• Nonvented sterile caps

• Leveling device

• Rolled towels or small pillows to support the patient during positioning

• Assess the patient and family understanding of the lumbar subarachnoid catheter system. Rationale: Any necessary clarification may limit anxiety for the patient and family.

• Explain insertion, patient monitoring, and care involving the lumbar subarachnoid catheter. Rationale: