Lumbar puncture

Table of Contents

Table of Contents

Published December 2023

Authors: Brandon Fainstad, MD1; Carolina Ortiz-Lopez, MD2; Henry Kramer, MD2; Glen J. Peterson, ACNP3; Pete Meliagros, MD4; Irene Ma, MD, PhD5

Section Editor: Josephine Cool, MD6

1 Associate Professor, Division of General Internal Medicine, University of Colorado.  2 Assistant Professor, Division of Hospital Medicine, University of Colorado. 3 Associate Virginia Commonwealth University. 5 Professor, Division of General Internal Medicine, University of Calgary.  6 Instructor of Medicine, Harvard Medical School, Section of Hospital Medicine, Beth Israel Deaconess Medical School. 

Objectives

  1. Describe the appropriate indications and contraindications to performing a bedside lumbar puncture.
  2. Achieve a minimum passing score (MPS) for performing a lumbar puncture using an assessment checklist in a simulation setting.  
  3. Practice performing a lumbar puncture with full or partial supervision in the clinical setting until demonstrating an Unsupervised Practice Standard (UPS).

Teaching Instructions

There are three stages to this procedure training and assessment process that aim to satisfy all components of the Learn, See, Practice, Prove , Do and Maintain framework.1

To effectively prime the learner for the simulation they should watch this procedural video, review the clinical checklist and take the pre-quiz the day before the simulation.

Ideally, the simulation training closely precedes (days to weeks) the clinical procedure, to best reinforce learning.  We recommend scheduling the simulations to be timed with the rotation where the learner is most likely to encounter the relevant procedure.

Both the learner and the instructor should perform the simulation with systematic and deliberate practice.  Treat the simulation as if it were a real-life procedure with sterile technique.  Simulation-Based Mastery-Learning (SBML), whereby the learner doesn't graduate the simulation training until they have met a minimum passing score (MPS), is a well-studied paradigm to ensure deliberate practice and effective feedback.2

 


Below is a Competency Assessment Tool (CAT) used for to assess for a minimum passing score (MPS) during simulation training and to assess competency for unsupervised practice standard (UPS) in the clinical setting.

The CAT includes three components:

1. Error-counting checklist

  • mirrors the clinical checklist
  • more specifically defines each potential error in an attempt to accurately capture mistakes.
  • Suggested cutoffs for mistakes allowed in the MPS (<12 mistakes) and UPS (<3).

2. Global Skills Assessment (GSA) – ranging from novice to expert.

  • Suggested cutoffs are ‘beginner' for MPS and ‘proficient' for UPS (<3).

3. Entrustment Score (ES) – ranging from ‘pre-clinical' (not ready to perform on live patients) to ‘educator' (ready to serve as an instructor and back-up for complex situations).

  • Suggested cutoffs are ‘full supervision' for MPS and ‘indirect supervision' for UPS (<3).

We recommend making the clinical checklist accessible to the learner and going through the following steps in a 60-90 minute simulation, depending on the trainee's experience with the procedure.

1. The instructor and trainee discuss the non-technical steps: indications, contraindications, consent process, & optimization of position and environment.

2. The instructor reviews the components of the procedural kit with the learner and demonstrates the proper technique for each step listed under “procedural steps” in the clinical checklist.

3. The trainee then familiarizes themselves with the kit components and practices the procedural steps.

4. The trainee signals when they are ready to do a full simulation with an assessment.  The assessment checklist is designed for the clinical setting and will have its limitations in a simulated environment.  Each simulation setting will vary in the steps can be physically demonstrated.  In such cases, the instructor should simply elicit a verbal explanation of the intended step or thought process. 

  • Reassemble the kit and simulator for a complete simulation.
  • With the checklist out of the learners view, quiz their knowledge on the non-technical steps, then place the clinical checklist back in clear view.
  • Perform each subsequent step from “Pre-procedural US” through “Procedural Steps”, then quiz the trainee on post-procedural steps.
  • Throughout the simulation, the instructor marks mistakes made or instances when prompting was needed to avoid a mistake.  At the end of the simulation, the instructor determines a global skills score and enstrustment score (see page 2 of the assessment checklist below)
  • The trainee repeats the simulation until they have accomplished a MPS:
    • Mistakes < 12 mistakes, Global > 2 and Enstrustment > 2

Provide support and guidance to the trainee while also taking notice of mistakes being made and when a prompt was needed to avoid mistakes. 

Complete the assessment tool either during or right after the procedure, depending on whether you are also wearing sterile protective equipment. 


 

Pre-brief– remove checklist from view

1. Assess learner experience – For learners who have not yet successfully completed a thoracentesis, the supervisor should plan to wear sterile protective equipment.

2. Confirm indication(s) and contraindications –This is often assumed by the time the decision to perform the procedure has been made, but in practice, many trainees lack this knowledge.

3. Confirm consent has been obtained via the patient or surrogate –  If consent is unable to be obtained, confirm the emergent indication for the procedure.


 

Setting-up– place checklist in clear view to reinforce learning through repetition and reduce procedural errors.7

1. Optimize patient positioning – for patient comfort and accessibility of the intervertebral space by maximizing forward flexion and minimizing R/L rotation of the spine.

    • Sitting upright – leaning forward on a bedside table with a pillow, and feet resting on a stool so knees are above the hips.
    • Lateral decubitus –
      • ankles, knees and shoulders staked with pillow supports as needed
      • Chin tucked and knees as high as possible toward the abdomen. 

2. Identify and mark insertion site(s)

By palpation

    1. Palpate the iliac crest and identify corresponding vertebral level, L4
    2. Palpate the spinous process from thoracic to lumbar spine to identify midline.
    3. Mark the L3-L4 and L4-L5 or L2-L3 interspinous spaces

Ultrasound (recommended)

    1. Using low-frequency transducer, start at the sacrum and slide transducer cephalad to map the lumbar spine
    2. In the transverse view, identify the midline of the spine & mark with a craniocaudal line across 3 spinal processes
    3. In the longitudinal view, identify the interspinous spaces & mark perpendicular to the spine

3. Gather all supplies

4. Perform a timeout with the patient's nurse before opening any sterile supplies. Include the patient in the time-out if possible.

5. Prepare sterile gear

    • Don mask, eye protection, and sterile gloves (cap and gown are optional).
    • Prep site with iodine-providone until dry or chlorhexidine scrubs x 30 seconds.  Sterilize an area larger than the aperture of the drape.

6. Prepare supplies

    • Draw up lidocaine using the largest needle or filtered catheter provided.  The smaller bore needles are reserved for anesthetizing the track. Then attach the 25g needle.
    • Identify the extension tubing with the three way stopcock to attach to the spinal needle once CSF is draining.
    • Place the manometer and collection tubes in an accessible location. 

Quiz

Quiz Answers

Clinical Checklist

Assessment Tool

Example procedure note

Indication: 
Procedure: Lumbar puncture
Performing provider: 
Supervising Physician (if applicable): 
Consent: obtained and saved in the chart
Time-out: performed
 

Procedure: Patient was comfortably positioned ***R/L decubitus or sitting upright leaning on a side table*** with maximum tolerated forward flexion of the spine.  Spinous processes of the lumbar spine were palpated and marked for midline and at least two interspinous spaces marked between ***L2 and L5***.  Ultrasound ***was/was not*** used to confirm the location of the midline and at least two interspinous spaces between L2 and L5.   The site was prepared with a ***iodine povidone or chlorhexidine scrub***, and a sterile perforated drape was placed over the insertion site.  An intradermal wheal of 1% lidocaine was injected with a 25g needle. A 21g needle was attached to the same syringe and advanced with negative pressure with an additional 1% lidocaine injected along the needle insertion path.   Then a spinal needle with the stylet was inserted along the same path, frequently pausing to remove the stylet to check for return of CSF.   Once CSF was visualized, extension tubing with three-way stopcock was attached.  ***to obtain opening pressure, a manometer was then attached and the stopcock opened to flow from patient to manometer.  The cm mark was noted at the point the CSF stalled.*** Then the stopcock was opened from the patient to the collecting port to collect ***X cc's*** of fluid in each of the four collection vials.  The stylet was then replaced and the needle was removed and a sterile air-sealed bandage was applied.   The patient tolerated the procedure well with no blood loss and minimal discomfort.

Amount of fluid drained: ***
Color of fluid: ***
Lidocaine amount: 5 ml***

References

  1. Sawyer, T., White, M., Zaveri, P., Chang, T., Ades, A., French, H., … & Kessler, D. (2015). Learn, see, practice, prove, do, maintain: an evidence-based pedagogical framework for procedural skill training in medicine. Academic Medicine90(8), 1025-1033.
  2. Dodd KC, Emsley HCA, Desborough MJR, Chhetri SK. Periprocedural antithrombotic management for lumbar puncture: Association of British Neurologists clinical guideline.Pract Neurol. 2018;18(6):436-446. doi:10.1136/practneurol-2017-001820
  3. Soni NJ, Franco-Sadud R, Kobaidze K, et al. Recommendations on the Use of Ultrasound Guidance for Adult Lumbar Puncture: A Position Statement of the Society of Hospital Medicine. J Hosp Med. 2019;14(10):591-601. doi:10.12788/jhm.3197
  4. https://proceduralist.org/lumbar-puncture/technique/
  5. Rochwerg B, Almenawer SA, Siemieniuk RAC, et al. Atraumatic (pencil-point) versus conventional needles for lumbar puncture: a clinical practice guideline.BMJ. 2018;361:k1920. Published 2018 May 22. doi:10.1136/bmj.k1920
Brandon Fainstad

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