Hravnak, Marilyn PhD, RN, ACNP-BC, FCCM, FAAN; Beach, Michael MSN, RN, ACNP-BC; Tuite, Patricia MSN, RN, CNS
Cardiovascular disease comprises complex interactions between the right and left heart, arterial and venous peripheral vascular system, and the neurohormonal system. Cardiovascular patient care situations may range in intensity from stable chronic disease up through the assessment, diagnosis, and management of acute and life-threatening hemodynamic compromise. The care of cardiovascular patients therefore requires clinicians to use a wide array of cognitive, assessment, and technical skills. Cognitive skills may include critical thinking and problem solving, as well as diagnostic reasoning. Assessment skills may include physical examination, single and 12-lead electrocardiogram interpretation, and hemodynamic monitoring. Technical skills may include intubation and cardiopulmonary resuscitation, as well as (for advanced practice nurses in particular) intubation and placement of central and arterial lines.
Assisting both students and practicing clinicians to master these skills can represent a challenge for educators. The didactic background for cardiovascular physiology, pathophysiology, assessment, and management most frequently occurs in the traditional classroom setting. However, such an approach does not necessarily translate into knowledge synthesis and application in the dynamic clinical setting. A newer technology known as high fidelity human simulation (HFHS) places the learner in a realistic simulated patient care environment, where practice can be observed and evaluated across a broad range of clinical scenarios. The purpose of this article is to describe the use of HFHS as a tool in cardiovascular education.
High Fidelity Human Simulation
High Fidelity Human Simulation was initially used in aviation, providing a setting in which pilots could perfect their flying skills and practice emergency responses in a controlled environment. Anesthesiology programs then adopted the use of simulation technology with the goal of providing trainees with protected opportunities to perform in critical clinical situations and use resources efficiently, while maximizing safe patient outcomes.1 Simulation continued to gain popularity in healthcare, and certified registered nurse anesthesia programs began to incorporate simulation into their programs. The goals of the programs were very similar to those of the anesthesiologist programs, and over time the certified registered nurse anesthesia programs have refined their simulation settings and scenarios to provide for increasingly realistic experiences.2-5
Rogers et al6 incorporated the use of simulation into a Critical Care Medicine elective for fourth year medical students and found that after 1 month, the student's ability to think and appropriately manage critically ill patients improved markedly. Nursing has also incorporated the use of simulation within their programs. Simulation has been used to provide realistic learning environments to promote critical thinking skills in critical care education, and has been useful in providing an avenue for advanced practice nursing students to perfect their abilities to handle critical incidents before they begin their independent practice.7-9 The University of Pittsburgh School of Nursing has incorporated simulation in a variety of undergraduate and graduate nursing courses. Students have the opportunity to refine their skills prior to or concurrent with clinical practica.
High Fidelity Human Simulation Laboratory
Students have access to simulation through various means at the University of Pittsburgh School of Nursing. In addition to a generic skills laboratory for routine physical examination, history taking, and common bedside nursing procedures, the advanced practice students can also participate in invasive procedure laboratories for central and arterial lines insertion and endotracheal intubation, using partial-body mannequins (torso, arm, intubation head). Additionally, HFHS is available in the Peter Winter Institute of Simulation, Education, and Research (WISER) Center to all of the nursing students. The School of Nursing also has its own Human Simulation Laboratory, located adjacent to the generic Skills Laboratory within the school, housing the Laerdal SimMan™ (Laerdal Medical Corporation, Wappingers Falls, NY).In addition, the School has a portable SimMan that is used to assist with scenarios that support the Trauma and Emergency Preparedness Program available to the acute care nurse practitioner and medical-surgical clinical nurse specialist students. This portable simulator can be used anywhere within the school, health center, community, and even the field.
The High Fidelity Human Simulation Laboratory within the school is composed of 2 rooms: the simulated operating theater or hospital room, and the control room. The theater contains an operating room bed, a physiologic monitor, an emergency cart with defibrillator, a wall source of oxygen supply, a functional mechanical ventilator, and infusion pumps. The room can be converted into an intensive care unit (Figure 1) or a hospital ward room. Intravenous fluids are connected to a drainage system so that the students can simulate infusing fluids (gravity feed or infusion pump) into the mannequin. There are 2 cameras mounted at 90-degree angles facing the bed to record the simulated experience from various views. The control room is contiguous to the simulated hospital room (Figure 2). A one-way mirror separates the 2 rooms and allows the faculty to control the scenario and view the student's actions within the theater/room, and a microphone system is used to communicate between the rooms. The control room houses the computer software and all of the sound and video equipment. The cameras allow for the scenarios to be videotaped or transmitted to classrooms. The videotapes provide the basis for the debriefing sessions to be described.
Laerdal's SimMan™ offers a variety of possibilities for the students regardless of the level of their clinical abilities. Students can practice auscultating heart, lung, and bowel sounds, with programming for various murmurs, adventitious, and diminished sounds. Students can palpate peripheral pulses, perform fluid resuscitation, and insert endotracheal, nasogastric, and urinary drainage tubes. A variety of monitoring capabilities are also available. A student can practice interpreting various cardiac arrhythmias, and observing arterial, central venous, and pulse oximetry traces. SimMan™ can be also be defibrillated. Blood pressure measurements can be obtained manually (auscultated in the left brachial area), or by noninvasive blood pressure monitoring, and the value observed on the monitor after the student simulates that the blood pressure has been taken. Hemodynamic tracings from a simulated arterial line can be observed with display of systolic, diastolic, and mean pressure values. The tracings perform in concert with the single-lead electrocardiogram tracings, and students can observe the consequences of ectopy and rhythm abnormalities upon arterial pressure. The airway can also be adjusted to provide for intubation complications such as edema of the tongue and pharynx.
The faculty has many options for designing the clinical scenarios, which are developed to meet the objectives of the course. The scenarios can either be preprogramed into the computer software and run automatically with the faculty participating in the bedside scenario, or run manually in real time by a faculty member from the control room. During preprogramed scenarios, the computer will automatically change the status of the mannequin if the students do not respond appropriately. For instance, in a hypotension scenario, until the student responds properly, the blood pressure will continue to fall, the heart rate will continue to increase, or an arrhythmia may occur, depending upon how the scenario is programed. The faculty can also override the programed scenario at any time with a hand-held controller. Preprogramming permits the faculty to run a scenario with minimal additional manpower support. When a faculty member operates the computer manually, they must physically adjust the physiologic parameters via the computer in response to the student's actions (appropriate or inappropriate).
Simulation has been a very valuable educational tool in our medical-surgical nursing courses and all of the critical care nursing courses at both the undergraduate and advanced practice levels. Faculty can provide students with the opportunity to function in a variety of unstable patient care scenarios in a protected environment. The students are able to practice cardioversion, defibrillation, and intubation, and can move through an entire cardiac arrest with various levels of autonomy (depending upon the educational level and course objectives) without risk for patient harm.
Before enacting the scenarios, students are asked to sign a confidentiality agreement so that the case scenarios and actions of class members are not discussed with other students. Developing the scenarios is very time consuming, and thus, they are often repeated. This confidentiality commitment provides an opportunity for all students to participate in each scenario and to be evaluated fairly. The students are also informed that they will be videotaped and that the tapes will be used for educational purposes during the debriefing period. The tapes are never shared-nor is the video fed to the classrooms-without the student's prior permission.
During the debriefing process, students participate with a faculty member in a discussion surrounding both the appropriate actions taken and suggestions of how instances may have been handled differently. For large classes of students, the debriefing can be handled in 2 stages. The smaller number of students who acted in the scenario will move to a small classroom with a faculty member and review the videotape, discussing key issues that occurred during the scenario. The larger number of student observers will watch the scenario in a classroom; the video feed during taping is transmitted to the classroom setting. These students, along with a faculty member, will then collectively work through a list of debriefing points and critical action items while reviewing the scenario in which their peers participated, such as appropriate planning and use of resources, judgment, and delegation. If the class is less than 10 students, debriefing is completed in a room with all students together. Alternatively, scenarios may be performed and reviewed with only a single student involved. Such structure can serve as a more formal evaluation tool for individual clinical performance. This can be a particularly useful tool when the employment of Distance Education limits the opportunities for faculty to directly observe student interactions with patients in a distant clinical setting. Debriefing is an integral part of the education process and allows faculty to stress important points as well as allowing students to learn from their own actions.
Utilizing HFHS as a Tool in Cardiovascular Education
We have developed scenarios wherein students can assess, diagnose, and manage cardiovascular patient care conditions such as:
* acute hypertension (mild, moderate)
* hypertensive urgencies and emergencies
* acute hypotension (mild, moderate, severe)
* cardiogenic shock
* cardiac arrhythmias (premature ventricular contractions, ventricular tachycardia, rapid atrial fibrillation, sinus bradycardia)
* acute coronary syndromes
* acute myocardial infarction
We find that it is helpful to organize both didactic teaching and clinical scenario development for cardiovascular conditions within the framework indicated in Figure 3. In this framework, likely well known to the readership, blood pressure (BP) is the product of cardiac output (CO) times systemic vascular resistance, and CO is in turn the product of heart rate (HR) times stroke volume (SV). Further, SV is determined by preload, afterload, and contractility. By teaching or fostering critical thinking for each pathologic cardiovascular problem from within the framework, the educator can assist the student in systematically thinking through the primary pathophysiologic mechanism parameter affected by the problem, the compensatory mechanisms parameter(s) that may be secondarily activated, and then entertain the intervention mechanisms parameter(s) that should or could be chosen.
Using rapid atrial fibrillation as an example: first, the student recognizes that CO is diminished. The primary pathophysiologic mechanism parameter alterations are: increased HR and decreased SV (due to inconsistent and inadequate filling times, loss of atrial kick). The compensatory mechanism parameter is: increased SVR (due to inadequate CO). The intervention mechanisms are: HR control (decrease ventricular response rate) and improvement of SV (reestablish HR regularity, foster adequate filling time and reinstitute atrial kick by reestablishing normal sinus rhythm). When identifying the interventions, students can learn to target them first to the primary pathophysiologic mechanism parameter, as the compensatory mechanism parameters may respond or reverse as the primary parameters move toward normality. Thus, for rapid atrial fibrillation, the interventions are first aimed at resolving HR and SV, and SVR may resolve as a consequence. Once students develop skills in this approach in the classroom setting-to assess and diagnose the primary problem, recognize the secondary mechanism(s), and choose interventions to first correct the primary problem-their critical thinking can be exercised dynamically in the simulation laboratory in the various scenarios. Both academic and clinical educators may find this approach helpful in organizing didactic and evaluative methods, and in fostering a framework for clinical thinking for students.
A series of figures provide an example of a clinical scenario for a patient with cardiogenic shock. It is meant to serve only as a brief example of the components whereby a scenario is developed, prepared for, enacted and evaluated, and is not comprehensive. This scenario was developed for use in the Acute Care Nurse Practitioner Program. Figure 4 provides the scenario's background, identifies the level of the learner, the clinical setting and support available, the baseline information provided to the student, and an overview of how the scenario should evolve for the educators. Figure 5 provides the details for the educators regarding preparation and setup for the patient, environment, and available resources, and serves as the checklist for setup in the patient room and controls in the laboratory. Figure 6 outlines a description of the roles and characteristics of the supporting actors, which serve as stage direction.
In this scenario, the bedside nurse is helpful but has limited clinical experience. The visitor is upset and distracts the clinician from immediate patient needs. The physician collaborator is available but busy and brusque. To be effective, the student will need to exercise effective communication and leadership skills, in addition to sound clinical judgment. Figure 7 provides notes for the operator. SimMan's™ baseline physiologic parameters are set, and there are suggestions for how the operator will adjust the parameters in response to interventions chosen by the student (there may be additional appropriate interventions not noted in the example). Lastly, Figure 8 outlines the debriefing points. As the educator and the student review the videotape, attention is focused upon key points in event management, judgment, situational awareness, resource utilization, and communication. The educator can emphasize recognition of the primary pathophysiologic mechanisms for cardiogenic shock, compensatory mechanisms, and intervention selection targeted to the mechanisms. Communication strategies and leadership skills can also be evaluated and discussed.
The scenario provided encompasses cognitive and psychomotor skills in the clinical practice of Acute Care Nurse Practitioners. However, this scenario can be (and has been) adapted to accommodate the education of undergraduate nursing students and clinical competency evaluation for practicing nurses. Both the operator guidelines and debriefing points can be adjusted to reflect the differing expectations for event management, judgment, situational awareness, resource utilization, and communication at the various levels.
HFHS Advantages and Disadvantages
The use of simulation in nursing and medical education has significant advantages as well as some disadvantages. Perhaps the most significant advantage to HFHS is the high degree of safety it provides for patients.10 Complex and difficult tasks are taught and practiced in an environment which provides experience without endangering actual patients. Abrahamson et al11 noted that anesthesia residents achieved proficiency in a shorter period and with fewer trials by utilizing mannequins for intubation training. Many training mannequins allow for changes to the airway, and trismus, limited cervical range of motion, or laryngeal spasm can be added to the scenarios. In addition to the airway characteristics, hemodynamic variables can also change throughout a scenario, allowing for an escalation of a critical event. (Inversely, hemodynamic compromise can be the inciting event, and loss of airway protection leading to need for airway support the consequence). By experiencing scenarios ranging from simple to extremely complex, clinicians can first learn basic techniques and advance to increasingly critical situations as their skills increase. This wide range of experience in a safe environment may enhance patient safety by increasing the practitioner's level of experience without placing real patients at risk. In this safe environment, skills may be practiced and critically evaluated (in concert with the learner). Because only "simulated" bad patient outcomes are possible, it is less stressful for the student, decreasing anxiety and enhancing learning.10,12
Human simulation has also been used for remediation of nursing students struggling with clinical skills. Haskvitz and Koop13 demonstrated that confidence and ability improved, thus improving patient safety. The utilization of simulation to teach, practice, and remediate skills cannot harm the patient, and by increasing experience and correcting problem areas, patient care should improve. Although there are no truly definitive studies, the literature does support the conclusion that simulation is helpful in the education of physicians and nurses.
The supportive, safe environment of HFHS provides an excellent opportunity for clinicians to experience the many varieties and subtleties of cardiovascular care. Hemodynamic parameters, and heart and lung sounds can be manipulated to permit SimMan to present with both stable and acute life-threatening conditions. However, the realism depends on the skill of the educator, both in writing the scenario and in manipulating the controls.
The opportunity for educators and learners to view the taped scenario and debrief is also an advantage of education utilizing HFHS. Taping the scenario and its subsequent analysis provides the opportunity for discussion of choices made, alternatives, mistakes, and suggestions to improve both skills and knowledge. Certain simulation software, such as that used by SimMan, also provides a time stamped record that may be saved, printed, and used in the analysis of the student's choices.
Disadvantages of HFHS are less well documented. Although students have stated that they find the simulations realistic and valuable,14 simulation is not reality. Mannequins have very realistic physical responses, which mimic various pathologies. Some allow for central and peripheral line placement or chest tube insertion. Many mimic bowel, lung, and heart sounds. At least one model can talk, although it would be difficult to carry on a conversation. However, few mannequins have realistic eyes, limiting physical examination. Most mannequins do not allow for all these functions and can be quite limited and specialized. Although safe manipulation of critical procedures is possible, true patient-provider interaction is limited.
Cost is a significant disadvantage. Computer-based HFHS can cost over $50,000 for the mannequin and support equipment. The environment necessary for full utilization of the experience; cameras and recording equipment; a dedicated area in which to establish the equipment; and additional mannequins of varied ages and physical conditions will add significantly to this figure.
Simulation training also requires a substantial investment of time and effort to write the scenarios, prepare the training environment, enact the scenario, and subsequent evaluation. Researching and writing valid realistic scenarios with appropriate parameters and responses for and from the mannequin can be extremely time intensive. The scenarios or experiences may take a relatively short period, whereas the analysis of the student's actions, mistakes, and options can be time consuming. The educator must become proficient in envisioning the scenario and preparing for the many pathways down which the scenario may proceed in response to the learner's decisions.
Finally, although students find simulations to be realistic,10,14 the scenario decisions and outcomes must be reliable and valid. Educators must be knowledgeable themselves and able to provide scientific evidence as the basis for the practice enacted.
High fidelity human simulation can be a valuable tool in cardiovascular education. Human simulation, whether it involves complex patient assessment and intervention or simple remediation for struggling learners, is safe and can be realistic. Learning is enhanced through repetition in a protected environment, with learners subjected to lower levels of stress and anxiety.12 However, there is still little documented evidence supporting the report that learner or clinical outcomes are improved by human simulation education, and further study is needed.10,15
The authors thank James Kelly, MSN, CRNA, for assistance in development of the shock scenario provided.
© 2007 Lippincott Williams & Wilkins, Inc.