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Simulation of fluoroscopic-guided lumbar puncture with a novel spine task trainer
  1. Saad Ali,
  2. Rishi Ramakrishna,
  3. Anup Alexander,
  4. Carina W Yang
  1. Department of Radiology, The University of Chicago, Chicago, Illinois, USA
  1. Correspondence to Dr Saad Ali, Department of Radiology, Section of Neuroradiology, University of Chicago Medical Center, 5841 South Maryland Avenue – MC 2026, Chicago, Illinois 60637, USA; saadali{at}uchicago.edu

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Introduction

Lumbar puncture is a frequently performed procedure for a variety of indications including withdrawal of cerebrospinal fluid for laboratory analysis, intracranial pressure assessment, administration of intrathecal therapeutic agents and myelography. Typically, this procedure is first attempted at bedside, and if unsuccessful, radiologists are requested to perform it under fluoroscopic guidance. As fluoroscopic-guided lumbar puncture (FGLP) requests are common, proficiency is required for general radiology and neuroradiology trainees. Pain physicians from speciality backgrounds including anesthesiology, neurology and physical medicine and rehabilitation also receive training in similar fluoroscopic-guided spinal procedures.

The use of fluoroscopy in guiding spinal procedures can be challenging to a new learner as it requires integration of anatomy and procedural technique while attempting to minimise fluoroscopy times and radiation dosage; the importance of the latter is indicated by data revealing medical radiation’s contribution of almost half of the American population’s average annual radiation exposure.1 The procedure is traditionally taught on actual patients who are awake, aware and without sedation. Unfamiliarity of a new learner with the procedure can lead to undue patient anxiety, pain and increased radiation dose, as well as increased stress on the learner.2,3 The ability to train for this procedure in a controlled environment with simulation prior to patient contact can improve both learner competence and patient experience.4 In this article, we describe our construct of a novel, lumbar spine task trainer for simulation of FGLP and its incorporation into an education module for the purpose of enhancing procedural training.

Task trainer construct

FGLP utilises fluoroscopy to visualise the osseous landmarks of the spine to optimise needle placement for access to the thecal sac and withdrawal of CSF. An adequate task trainer requires a spine model which is radiopaque to be visible under fluoroscopy, replication of anatomic layers which are traversed in the procedure (skin, subcutaneous tissues, ligamentum flava, etc.) with realistic tactile responses from each, and a fluid-filled tube that simulates the thecal sac for CSF withdrawal. To fulfil these requirements, we acquired a mannequin (Sawbones, Washington, USA) which was originally designed for epidural injection training. We customised it to suit our needs for FGLP (Figure 1).

Figure 1

Lumbar spine task trainer customised for FGLP with its components. Fluoroscopy images obtained during simulation are also shown.

It consists of a soft foam torso extending from the mid back to the upper thighs. A replaceable soft tissue insert made of a self-expanding foam overlies the spine and allows for repeated needle sticks with similar tactile feel to the subcutaneous tissues. The spine is a plastic composite with a radiopaque coating extending from T6 to the sacrum. It is anatomically accurate and without degenerative or other pathological changes to facilitate new learner education. The plastic material allows for long-term durability to direct needle sticks. The radiopaque coating allows for visualisation of the spine under fluoroscopy. A composite material deep to the lamina represents the ligamentum flavum and provides accurate tactile release experienced during a lumbar puncture. A latex tube recreates the thecal sac and can be connected to an elevated saline bag to simulate actual return of fluid with needle puncture. The latex tube has a specialised coating that increases the number of needle sticks allowed at each level of the thecal sac, which is approximately 10–15 times per level. The total cost of the mannequin is approximately $2500 and $80 for the soft tissue insert. The spine does not need replacement as the plastic is quite durable to needle sticks. However, the material recreating the ligamentum flavum is expected to lose its tactile resistance after an undetermined number of needle sticks. The latex tubing can be easily replaced from a hardware store at a nominal cost, with marginal loss in durability without the special coating. The ongoing costs of the mannequin mainly consist of the latex tubing and soft tissue insert.

FGLP simulation education module design

First-year radiology residents are the primary learners for this simulation device. Each first-year radiology resident before or during their first neuroradiology rotation would undergo simulation in FGLP prior to first patient attempt. A simulation curriculum has been developed and includes a presentation with information including the purpose, indications, and contraindications of FGLP, as well as anatomical considerations, procedural tasks and familiarisation with the unit. Obtaining pertinent history, physical examination, consent and pre-procedural labs are also reviewed. Once familiar with the anatomy and procedural steps, the trainee then observes the steps as demonstrated by a more senior trainee or faculty member on the task trainer in the fluoroscopy suite, followed by being actively instructed as he/she performs the procedure on the trainer. The module concludes in a hybrid simulation, with performance of the procedure on the task trainer accompanied by a standardised patient. The new learner then performs the FGLP on a clinical patient under the supervision of a senior trainee or faculty member.

Simulation evaluation

The simulation is evaluated using an objective checklist completed by a neuroradiology faculty member during the hybrid simulation and on the first clinical attempt with the patient. Subjective surveys are completed by the participant with regard to their comfort utilising a 5-point Likert scale (very comfortable to not at all comfortable) with the various FGLP steps. Number of failed puncture attempts and fluoroscopy times are also recorded. A follow-up survey post-procedure assesses how helpful the trainees found the simulation curriculum including how realistic the task trainer was compared with the actual patient.

Ultimately, fluoroscopy times of simulation participants on their first clinical attempt will be compared with those of trainees in the prior years without simulation training. Patient satisfaction surveys will also be evaluated, comparing results from trainee operators having received simulation training with those without. We believe that this simulation curriculum utilising a novel FGLP-customised lumbar task trainer will result in increased trainee procedural comfort and improved patient safety, including decreased failed puncture attempts and reduced fluoroscopy times and radiation dose.

References

Footnotes

  • Funding None.

  • Competing interests None declared.

  • Provenance and peer review Not commissioned; internally peer reviewed.

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