VOL 25, NO 2
APRIL 2011
EDITORIAL Simulation: The Importance of “Hands-On” Learning
T
HE FIELD OF anesthesiology has been involved in simulation for medical education since the initial cardiopulmonary resuscitation simulator was developed by Dr Safar more than 50 years ago and the successful Sim-Man by Laerdal Medical (Stavanger, Norway) in the 1990s.1,2 Building upon the educational value of “hands-on” learning without the clinical productivity and time constraints, patient risk, and lack of experience in rare clinical scenarios, simulation has developed a strong foothold in medical education. Simulators exist for a multitude of anesthesia-related areas including difficult airway, vascular access, bronchoscopy, anesthetic management, and crisis management training.3 However, until recently, clinically appropriate, commercially available echocardiography simulators were lacking. In a world setting of broadband Internet access and ever-increasing computer power, specifically with faster and more powerful graphics processing units, the graphic-intensive process of echocardiography simulation has become possible to fulfill the “hands-on” education of transthoracic and transesophageal echocardiography (TEE). This successful development comes at a time when practice guidelines now include indications for TEE in noncardiac surgery and the new development of basic certification in perioperative TEE is prompting multitudes of anesthesiologists to pursue proficiency.4 Unfortunately, learning TEE is fraught with obstructions and impediments to success. These difficulties include learning cardiac anatomy as well as the mental 3-dimensional (3D) reconstruction from 2-dimensional (2D) slices. Learning the spatiotemporal relationships, structural identification, and omniplane rotation can be an intimidating task without the “handson” experience of probe manipulation and image acquisition. Potential patient risk, operating room time constraints, the availability of transesophageal echocardiographic-trained anesthesiologists, and the typical use of TEE in busy cardiac suites limit the availability of “hands-on” exposure to the noncardiac anesthesiologists. Lastly, and significantly important to becoming proficient in TEE, is the ability to discriminate the normal from abnormal. With limited clinical exposure, this ability is
slow to acquire. Echocardiography simulators attack these impediments head on. Beyond the simple 2D display of transesophageal echocardiographic views, simulator technology has expanded to include the simultaneous display of virtual reality anatomically correct 3D cardiac structures. Coordinating the transesophageal echocardiographic view of the 2D ultrasound image with the 3D display assists the user in observing the relationship of the probe position, the transesophageal echocardiographic image, and omniplane rotation, fulfilling the mental reconstruction requirement of transesophageal echocardiographic proficiency. In addition, the ability of the systems to integrate lifelike echocardiography probes with the 2D and 3D displays allows the user to learn “hands-on” probe manipulation, image acquisition, and cardiac anatomy identification. Currently available echocardiography simulators may be broadly separated into 2 categories: Internet based and mannequin based (Table 1). Internet-based systems, such as CT2TEE (http://www.ct2tee.agh.edu.pl/) and Virtual TEE by the Toronto General Hospital Department of Anesthesia (http://pie. med.utoronto.ca/TEE/index.htm), use a modern web browser with a standard mouse and keyboard interface to display and manipulate both 2D and 3D images. Mannequin-based echocardiography simulators such as Blue Phantom (Seattle, WA), EchoCom (Leipzig, Germany), Heartworks (Inventive Medical Ltd, London, UK), and Vimedix (CEA Healthcare Inc, Montreal, Canada) incorporate a mannequin and integrated lifelike echocardiography probes to simulate “hands-on” probe manipulation and image acquisition. They largely differ in image quality, 3D model display, TEE only versus combined transthoracic echocardiographic and transesophageal echocardiographic simulation, and the inclusion of pathologic states. In this issue of The Journal of Cardiothoracic and Vascular
© 2011 Elsevier Inc. All rights reserved. 1053-0770/2502-0001$36.00/0 doi:10.1053/j.jvca.2011.01.007
Journal of Cardiothoracic and Vascular Anesthesia, Vol 25, No 2 (April), 2011: pp 209-211
209
210
Table 1. Overview of Currently Available TEE Simulation Models Name
Internet or Mannequin Based
Echocardiographic Modalities
Other Information
No 3D model present
Contains normal anatomy and 2 congenital heart disease data sets
Free, web-based, limited functionality with regards to simulated probe manipulation
Keyboard and mouse manipulation of internal and external cardiac structures
Currently contains normal anatomy as well as a synopsis module with 2 pathologic states
TTE and TEE
Nonbeating simulated echocardiography windows
No 3D model present
Mannequin
TTE and TEE
Coupled real 3D echo datasets to a virtual 3D heart model, yielding 2D echo slices
Full examination and manipulation of internal and external cardiac structures
Pericardial effusion with ability to simulate pericardiocentesis procedures Pathologic datasets such as congenital heart disease have been incorporated into the software
Free, well-designed teaching modules that include nonstandard views, spectral and color Doppler, 3D echocardiography, and online quizzes Replaceable fluid for pericardiocentesis; limited by nonbeating images
Heartworks (Inventive Medical Ltd, London, UK)
Mannequin
TEE only
Detailed 3D virtual-reality heart model via realtime rendering engine coupled to rendered ultrasound images
Ability to make planar slices through the model in any orientation, with labeled and detailed structures
Normal anatomy only
Vimedix (CEA Healthcare Inc, Montreal, Canada)
Mannequin
TTE and TEE
Detailed real-time 3D virtual reality heart model coupled to rendered ultrasound images
Ability to make planar slices through the model in any orientation
Normal anatomy plus a large variety of downloadable pathologic states
Internet
TEE only
Virtual TEE by Toronto General Hospital Department of Anesthesia
Internet
TEE only
Blue Phantom (Blue Phantom, Seattle, WA)
Mannequin
EchoCOM (EchoCOM, Leipzig, Germany)
Image Source
3D Manipulation
Available in neonatal, pediatric, and adult sizes; probe connects to a PC, via standard USB, running EchoCom software Uses Heartworks provided computer with highcapacity graphics processing unit card; highly detailed anatomy with 160 described structures M-mode, linear, and area calculations, with pulsed wave and color Doppler on future software update
TIMOTHY M. MAUS
Pathologic States
Rendered from electrocardiogramtriggered cardiac computed tomographic images 3D digital model correlated to actual standard TEE views
CT2TEE
THE IMPORTANCE OF “HANDS-ON”
211
Anesthesia, Dr Bose et al5 present a study evaluating the utility of echocardiography simulation in the education of echocardiographic-naive first-year anesthesia residents. Comparing a short curriculum based on “hands-on” time with the Heartworks TEE simulator (study group) with a conventional curriculum of transesophageal echocardiographic guideline review, textbooks, and anatomy atlases, the authors showed statistically significantly improved post-training scores on written tests of image acquisition and structure identification in the study group. They concluded that skills such as basic image acquisition and interpretation can be reliably taught in a simulated environment. In the February issue of the Journal, the same authors detailed the use of a different simulator, the Vimedix transthoracic echocardiographic and transesophageal echocardiographic simulator, with particular focus on the benefit of comparing simulated normal versus abnormal views.6 Their conclusion was that the additional ability of a simulator
system to portray pathologic ultrasound views further enhances the virtual experience and echocardiography training. Anesthesiologists, both cardiac and noncardiac alike, are challenged with learning the skills of a perioperative echocardiographer. Commercially available echocardiography simulators present visually stunning 3D cardiac representations that allow full manipulation resulting in high-yield cardiac anatomy and echocardiography education. Studies showing the success of echocardiography simulation in medical education will serve to keep simulation at the forefront, helping to hurdle the obstacles of limited access to patients and potential patient risk while providing a truly “hands-on” experience. Timothy M. Maus, MD Department of Anesthesiology University of California, San Diego San Diego, CA
REFERENCES 1. Grenvik A, Schaefer J: From Resusci-Anne to Sim-Man: The evolution of simulators in medicine. Crit Care Med 32:S56-S57, 2004 (suppl) 2. Grenvik A, Schaefer JJ 3rd: Medical simulation training coming of age. Crit Care Med 32:2549-2550, 2004 3. Cumin D, Merry AF: Simulators for use in anaesthesia. Anaesthesia 62:151-162, 2007 4. American Society of Anesthesiologists and Society of Cardiovascular Anesthesiologists Task Force on Transesophageal Echocardiography: Practice guidelines for perioperative transesophageal echocar-
diography: An updated report by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists Task Force on Transesophageal Echocardiography. Anesthesiology 112:1084-1096, 2010 5. Bose RR, Matyal R, Warraich HJ, et al: Utility of a transesophageal echocardiographic simulator as a teaching tool. J Cardiothorac Vasc Anesth 25:212-215, 2011 6. Matyal R, et al: Transthoracic echocardiographic simulator: Normal and the abnormal. J Cardiothorac Vasc Anesth 25:177-181, 2011