Vol 6 | Issue 1 | January-April 2020 | page: 9-10 | Shiv Kumar Singh, Tuhin Mistry
Author: Shiv Kumar Singh [1], Tuhin Mistry [2]
[1] Department of Anaesthesiology, Royal Liverpool University Hospitals, Liverpool, United Kingdom.
[2] Department of Anaesthesiology, AIIMS, Raipur, Chhattisgarh, India.
Address of Correspondence
Dr. Tuhin Mistry,
G-304, Jainam Planet, Tatibandh, Raipur 492099, Chhattisgarh, India
E-mail: tm.tuhin87@gmail.com
A Novel Plant Based Ultrasound Phantom
Introduction
In most of the ultrasound guided regional anaesthesia workshops, anaesthesiologists usually concentrate on identification of nerves & plexus on human volunteers and practice needling techniques on phantom. Proper needle insertion technique and correct manipulation are two important skills for ultrasound-guided peripheral nerve blocks. These skills can be sharpened by practicing on ultrasound phantom. It also helps anaesthesiologists to develop, practice and maintain the skills needed for regional anaesthesia and vascular access procedures [1]. But the use of phantoms is often limited due to the cost of the blue phantom [2]. Many courses use meat-based products like turkey legs or porcine models but these may not be acceptable to everyone [3,4]. Vegetable based models using gelatine also may not be acceptable as it too is made from animal products. We describe novel use of Aloe Vera (AV)stem as phantom for US guided needling training. This natural AV gel-based phantom can be used for scanning, needling and refine other relevant skills. The AV phantom can be constructed from low cost, readily available natural source and is reusable.
Various materials have been used to make ultrasound training phantoms. Commercially available phantoms are expensive and homemade nerve block models are cumbersome to prepare [5]. The Aloe Vera gel is obtained from Aloe Vera plant (Aloe barbadensis miller). It is a natural product which has been used for centuries in various field specially in dermatology. Aloe Vera leaves are triangular and fleshy with serrated edges. Each leaf contains an inner clear gel which is made of 99% water and other substances (glucomannans, amino acids, lipids, sterols and vitamins) [6]. Aloe Vera is odorless and semi-transparent unlike meat-based models.
Preparing the Aloe Vera US Model
The covering of the leaves is non-echogenic and hence the pulp from Aloe Vera leaves is separated and placed in layers and covered with a Transparent Dressing(TegadermTM) film to hold them together (Fig. 1(a)). The pulp can also be placed in a container in multiple layers to create a deeper model. A thin plastic tubing or 1-0 thread is then inserted to create an echo genic shadow for depicting a nerve to practice hand-eye coordination (Fig.1 (b, c)).
Based on our routine use of this phantom, we believe it is a natural, inexpensive and effective tool for learning of ultrasound-guided peripheral nerve blockade by novices. Aloe Vera is odorless and can last for days if kept refrigerated for repeated use. The Aloe Vera model has similar consistency pulp to human tissue in terms of feel and echogenicity. Such a model may be useful for those providing training at courses in ultrasound-guided peripheral nerve blocks. Our correspondence adds another indication of wide spectrum use of Aloe Vera gel and a vegan model for hand-eye coordination practice for US guided nerve blocks.
We have not compared it with established phantoms or assessed their relative performances. The leaf model we have appears to be small but larger phantom can be made using multiple layersfor training of deeper blocks. Artificial skins as used in mannequins or even cling film can also be used instead to the plastic cover. Quantification of echogenicity of the model as compared to other models can be done in a comparative study. Since this is a vegetable-based model, it would definitely provide universality in usage.
References
1. Sultan SF, Iohom G, Shorten G. A novel phantom for teaching and learning ultrasound-guided needle manipulation. J Med Ultrasound 2013; 21:152–5.
2. https://www.bluephantom.com/product/Regional-Anesthesia-Ultrasound-Training-Block-Model.aspx?cid=394
3. Farjad Sultan S, Shorten G, Iohom G. Simulators for training in ultrasound guided procedures. Med Ultrason. 2013;15(2):125–131.
4. Sparks S, Evans D, Byars D. A low cost, high fidelity nerve block model. Crit Ultrasound J. 2014;6(1):12.
5. Rathbun KM, Brader WT, Norbury JW. A simple, realistic, inexpensive nerve phantom. J Ultrasound Med 2019;38(8):2203-7.
6. Surjushe A, Vasani R, Saple DG. Aloe vera: a short review. Indian J Dermatol. 2008;53(4):163–6.
How to Cite this Article: Singh S K, Mistry T | A Novel Plant Based Ultrasound Phantom | Journal of Anaesthesia and Critical Care Case Reports | Jan-April 2020; 6(1): 9-10. |
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