Performing LPs and Myelograms

Lumbar Puncture • Done for CSF sampling and/or CSF pressure measurement • Use 22G or smaller needle • “non-cutting” or “pencil tip” vs spinal needle

Figure 12-6. https://obgynkey.com/spinal-epidural-and-caudal-anesthesia/

Cutting vs Non-cutting Needles

Rochwerg B, Almenawer S A, Siemieniuk R A C, Van O, Agoritsas T, Lytvyn L et al. Atraumatic (pencil-po versus conventional needles for lumbar puncture: a clinical practice

Lumbar Puncture • Pre-procedure checklist: 1. Coagulation

• SIR low-risk guidelines: • INR correct to within 2.0-3.0 • Platelets: transfuse if below 20k

2. Anatomy

• Review any imaging of lumbar spine (this includes CT abdomen/pelvis, radiographs, MRI localizer images) • If available, MRI – check conus location • Ideal levels to target: L2-3 and L3-4

Lumbar Puncture • Positioning: Prone versus Lateral Decubitus • Supplies - lumbar puncture tray, which includes:

• CSF manometer, CSF collection tubes (labeled 1-4), syringe and 25g needle for lidocaine administration, tubing, 3-way stopcock, betadine • Spinal or non-cutting needle

Checking CSF Pressure • Normal CSF Pressure: 5-25 cm H2O

Fig 1. Yücel, Duygu & Ülgen, Yekta. (2023). A novel approach to CSF pressure measurement via lumbar puncture that shortens the measurement time with a high level of accuracy. BMC Neuroscience. 24.

10.1186/s12868-023-00805-4.

Picking level

Picking level

Picking level

Picking level

Procedural Tips • Use lateral to determine depth if using C arm • Valsalva and long tubing to speed collection • Rotate needle if CSF flow slowing • Short supine bedrest following procedure • 30 min to 2 hours

Myelography • Same steps as lumbar puncture • Once determined to be intrathecal, begin injecting contrast • Inject contrast in AP or Lateral projections

• Ensure using Omnipaque 180/240/300 • Volume: 3 gram max dose

• cervical: 10 mL of 300 mg iodine/mL • whole spine: 15-17 mL of 240 mg iodine/mL • lumbar spine: 15-17 mL of 180 mg iodine/mL or 10 mL of 300 mg iodine/mL

Myelography

Myelography

Questions?

email: jfage@uwhealth.org