Paramedian thoracic epidural training model
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KeywordsEpidural Space Spine Model Needle Insertion Phantom Model Metal Pipe
To the Editor,
Insert the epidural needle 1-2 cm lateral to the spinous process of the vertebra;
Advance the needle perpendicular to the skin until it contacts the lamina;
Redirect the needle approximately 15° medially to “walk off” the lamina; and
Angle the needle cephalad and continue the “walk off” technique to locate the epidural space. Steps 3 and 4 must be performed separately, as the epidural space may be missed if the needle is “walked off” diagonally (i.e., medial and cephalad).
This procedure can be difficult to master. Accurate placement of the needle requires fine motor skills which are best learned through hands-on practice. Phantom models have been developed to allow trainees to refine their needle guidance skills for various procedures throughout their training.4 Since no phantom model is currently readily available for the paramedian approach to a thoracic epidural, we designed a simple and economical phantom which alerts the trainee immediately when the needle contacts the epidural space.
This phantom model has several advantages, including that it is inexpensive and easy to maintain. Needle tracks from repeated punctures are removed easily by remoulding the plasticine. Furthermore, the depth of the plasticine covering the spine model can be increased to simulate an obese patient, and finally, immediate feedback is provided when the needle tip enters the simulated epidural space. While this model allows the learner to practise “walking off” the lamina, it does not provide the opportunity to practise the loss of resistance technique. Also, this model does not reproduce the tactile feeling of different tissue resistances encountered when a thoracic epidural block is performed in a patient. We have used this model as a teaching tool from 1999 to the present with positive learner feedback. It has been used with hundreds of trainees in a number of regional anesthesia workshops at provincial and national meetings. This initial experience suggests that further validation of this model is warranted to evaluate outcomes (successful thoracic epidural placement).
Conflicts of interest
- 2.Rasoulian A, Lohser J, Najafi M, Rafii-Tari H, et al. Utility of prepuncture ultrasound for localization of the thoracic epidural space. Can J Anesth 2011; doi: 10.1007/s12630-011-9548-9.