Simulation Technology in Anesthesiology

“How do you get to Carnegie Hall?

Practice! Practice! Practice!”

Anonymous

A simulator is a device or software program that is designed to reproduce or represent effects simulating phenomena likely to occur in reality. Perhaps the most familiar simulator is the flight simulator, which accurately replicates the look and feel of an airplane cockpit. Using a flight simulator, a pilot may practice takeoffs, landings, navigation procedures, and critical incidents without risk to passengers, crew, or expensive aircraft. Simulation technology has become an important educational tool in many complex, high-risk, dynamic environments such as the nuclear power and petroleum industries, the military, law enforcement, and especially, in aviation, automotive, and space travel.¹ Simulators reduce the financial cost of testing and training personnel and reduce the risk to human life. With production pressures in medical/dental education that limit instruction time and patient availability, the expanding algorithms for patient diagnosis and management, and the major advances in computer and simulation technology, the medical education community is beginning to recognize the potential of simulation concepts and technology.²

Simulation strategies span the entire gamut of medical education from simulation laboratories to strengthen medical student skills in patient examination³ to the development and implementation of standardized patients used as simulators to assess clinical performance by the Educational Commission for Foreign Medical Graduates.⁴ Simulation technology is at the forefront in introducing and expanding revolutionary endoscopic and laproscopic surgical techniques.^5,6 Many medical specialties such as cardiology, internal medicine, and critical care medicine are embracing this innovative technology.^7–9 Nursing and other medical personnel such as cardiac perfusionists are utilizing simulation technologies in their curricula.^10,11 Anesthesiology, which has often used the aviation model in the discussion of critical incidents, has been a driving force in the medical community in introducing realistic, complex simulation concepts.¹²

Dental sedation/anesthesia practice, with its emphasis on perioperative critical event training, the treatment of the complex emergency patient, and the development of emergency algorithms, may greatly benefit from the inclusion of simulation technology in training programs as well as part of continuing education initiative for oral and maxillofacial surgeons and dentist anesthesiologists.

BACKGROUND

No matter what type of simulator technology is employed, two important concepts must be strictly adhered to in order for the experience to be valid and relevant—the fidelity and the presentation of the simulation. Fidelity is how closely the simulation actually replicates the actual clinical event. The higher the fidelity of a simulation, the more the simulator mirrors reality. The representation of the simulator is the summation of its outputs and is what actually constitutes the simulated event. Representation may be accomplished via computer-based simulators with data presented on the screen or with an advanced, realistic clinical environment with all types of interactive monitors, manikins, and anesthesia equipment.¹³

Anesthesia providers are expected to diagnosis and immediately treat many potentially disastrous complications, although many of them are uncommon and may not be encountered in training or clinical practice. The greater the representations that mimic the clinical setting—stress, noise, damaged or unfamiliar equipment, misleading signs and symptoms, alarms, and multiple problems complicating the decision process—the greater the extrapolization of the stimulation experience into the real world. Simulation technologies’ greatest advantage is that routine and emergency procedures can be practiced without concerns for patient safety since simulation poses no risk to patients. It is possible to present routine and uncommon events repeatedly where the cause is known and errors can be allowed to occur without risk or the need for intervention. Students can be exposed to serious or uncommon events that they may not otherwise encounter during their training. The events can be stopped, dissected, discussed, critiqued, and repeated with different algorithms and outcomes. Standardization of protocols in specific emergencies can be defined and reinforced.

Whether computer screen-based or realistic, simulators allow for the participant to input clinical actions and receive appropriate output about the result of these decisions. It should be remembered that medical simulation technology is a relatively new educational tool. To date, the fidelity of anesthesia simulators is not as sophisticated as other industrial and military ones, and the simulators have other limitations inherent in all game playing models (eg, the participants being hypervigilant and being unable to suspend disbelief and enter the simulation’s “reality”).

Realistic anesthesia simulators can mimic the sights, sounds, feels, looks, and even smells of the operating room and use sophisticated manikins, video recorders, real anesthesia and monitoring equipment, and an operating room environment complete with personnel to achieve fidelity. As a result, they are very expensive to construct, operate, and maintain. Computer-based trainers offer lower cost and better accessibility and use existing computer resources.

TYPES OF SIMULATION PROGRAMS

Computer Screen-Based Simulation Programs

Early screen-based simulators first appeared in the late 1980s and concentrated on simplistic emergency scenarios with limited graphical representation. Three excellent examples of screen-based programs are Gas Man®, BODY Simulation for Anesthesia®, and Anesoft Anesthesia, Sedation, ACLS, Critical Care and Hemodynamic Simulator Software® (Anesoft Corporation).

Gas Man (Med Man Simulations, Inc) is a revolutionary, anesthesia-orientated educational computer simulation program, the goal of which is for the user to learn the theory and application of inhalation anesthesia uptake and distribution via simulation software and an accompanying textbook.¹⁴ This program has been updated through the years and is an excellent method of explaining and mastering these concepts.

BODY Simulation for Anesthesia (Advanced Simulation Corp) is a multimedia, interactive anesthesia software trainer that simulates an operating room environment. The user may select monitors, intravenous lines, syringes, infusions, type and doses of drugs, type and flow rates of fluids, gas flows, and ventilation parameters as well as actions such as specific airway management or auscultatory confirmation endotracheal tube placement. Necessary information is obtained by observation, monitors, or queries, and either routine clinical task or critical operating room incidents may be explored. In addition to the standard scenarios and patients provided, one may also create an almost unlimited number of patients and scenarios that can also be saved for further study or be tailored to the specific objectives of a curriculum. One hundred fifty different clinical and physiologic parameters may be graphically displayed, either viewed in real time as events occurring during a case or recorded for subsequent review.

Anesoft Anesthesia and Sedation Simulators® are designed to both teach basic anesthetic and sedative concepts and to train healthcare personnel in anticipating and managing critical events. Both of these programs rely on pull-down menus on the computer screen to access patient evaluation, physical examination, monitoring data, and help menus. In addition to these menus, there are graphic representations of monitors, clinical photographs, and interventions. In the sedation simulator, an audible pulse oximetry beep corresponding to the oxygen saturation contributes to the realism of the scenarios presented. The anesthesia simulator has 80 case presentations and also has the capacity to track the drug levels and effects of more than 90 drugs. The Sedation Simulator includes 40 simulated cases and the ability to chose whether some of the cases will be routine with no critical incidents, will have selected critical incidents (eg, hypotension, hypoxia, anaphylaxis, etc.), or will have a randomly generated critical incident.

Computer simulation programs do not impart clinical manual skills nor do they offer true fidelity of the work environment, with its myriad of distractions, personnel pressures and interactions, equipment malfunction, and preparation coupled with patient and production pressures. They do, however, let the users proceed at their own pace and are an excellent method of demonstrating pharmacodynamic and pharmacokinetic theories and clinical applications of drugs. Their low cost and the almost universal accessibility to computer resources will continue to make computer screen simulators a popular first step in simulation technology.

Realistic Simulation Technology

The introduction of realistic anesthesia simulators is a breakthrough in the evolution of anesthesia simulation technology. This technology employs the use of sophisticated mannequins, real anesthesia machines, and monitors. The simulators may also include the use of full-scale operating rooms staffed with people acting as operating room personnel (eg, obnoxious surgeon, intimidated residents, distracted nurses). It is estimated that there are approximately 100 of these simulators in use throughout the world designed and built by two major manufacturers, MedSim Advanced Medical Simulations, Ltd, and Medical Education Technologies, Inc.

The realistic simulator consists of a full-sized manikin controlled through a Windows-like software program by an operator. Airway, ventilation, and cardiovascular parameters are controlled and changed by the software operator to mimic a variety of pathologic states, disease complexes, and physiologic responses to pharmacologic interventions. The realistic manikin has electronically generated cardiac and breath sounds, dynamically controlled airway anatomy, palpable pulses, and the ability to duplicate neuromuscular blockade. The ability to perform all types of airway maneuvers on these manikins, including mask and laryngeal mask ventilation, endotracheal intubation, and circothyrotomy, is of special interest to anesthesia providers. The respiratory system consists of computer-controlled electromechanical lungs with changeable compliance and the ability to eliminate carbon dioxide so that a capnograph can be used to monitor ventilation and evaluate airway manipulations and interventions. All administered drugs are recorded by an automatic drug recognition system and physiological and pharmacological models are integrated to allow for simulation of all body compartments. Among the many other features unique to these systems are moveable joints and spontaneous eye opening with appropriate papillary responses. Pediatric-sized manikins are also available.

Realistic simulators allow for the representation of complex or simple scenarios with a myriad of different patient types, which can be designed for specific purposes and stored in computer memory for replay. Although the primary utility of these simulators is to duplicate intraoperative anesthetic events, they can also be used to teach medical/dental students and residents basic manual skills in airway management and aid in physiology and pharmacologic education, emergency shock-trauma management, and ACLS training including arrhythmia diagnosis and treatment and fluid management.

The most unique application of the realistic simulator is in the area of interpersonal performance training in crisis situations, termed anesthesia crisis resource management (ACRM). This is an area of applied performance assessment known in the airline industry as cockpit resource management and stresses communication skills, appropriate roles and response, emergency reactions, and the need for constant reassessment of an evolving critical incident. Video taping of the simulation scenario followed by an intensive, and most importantly, nonthreatening review of the training exercise complete this program.

Realistic simulators provide a platform that replicates critical incidents with greater fidelity than screen-based programs but will never truly be able to replace a live patient with all of its many variables and complexities. The cost of the comprehensive realistic simulation centers is extremely high, not only for the computer hardware, software, mannequin, monitors, anesthesia machines, and physical plant but also for the dedicated operating personnel.¹⁵ Many individuals also do not respond well to having their performance so intensely scrutinized, while others have difficulty accepting the artificial environment of the simulator and suspending disbelief.

FUTURE DIRECTIONS

Although educators and students uniformly express a strong positive attitude toward the learning experience provided by simulation, it is difficult to document quantitatively that simulator training improves clinical performance. This lack of quantitative data may be due to the fact that simulators, especially realistic ones, do not teach facts but rather enhance the ability to manipulate multiple data and hopefully improve human performance. Medical science is just beginning to attempt to verify the validity of simulator training in anesthesia and other disciplines.^16–18 It is appropriate to note, however, that the aviation industry is also unable to quantitate the value of the cockpit simulator, but it is used extensively because there is no other tool available to address crisis management issues with such fidelity.

Simulation technology will aid in the introduction of new techniques, drugs, and monitoring equipment. With proper validation, it may also serve to demonstrate competency in specific areas prior to allowing residents to perform these maneuvers on patients. Simulation may prove to be an excellent education tool to update and recertify practicing health care professionals and could become an important adjunct to office inspection and evaluation conducted under the auspices of dental professional societies and state boards of dental registration.

It is evident that medical simulation technology is still in its infancy, but with the addition of virtual reality components, increased computing power, and enhanced software, the use of simulation technology will provide a new dimension for education in our training and continuing education programs. A recent newspaper column on human errors in medicine, which concluded with tour of a realistic anesthesia simulator, discussed the potential of this technology by summarizing:

A culture of safety is still the long term goal. But here in all-too-realistic O.R., a society that is focusing on medical mistakes can glimpse how much better off we’d be if most of the mishaps happened to Nancy (the manikin).¹⁹