Olsen, Martin E. MD
* The concept of medical simulation has existed for centuries, but its use has increased during the past decade.
* Medical simulation has been confirmed as an excellent medical education tool in peer-reviewed studies.
* Anthrax infection is a medical condition that carries an extremely high mortality rate with late diagnosis, but a significantly improved mortality rate when the diagnosis is made early after exposure.
* Medical simulation allows physicians and medical learners to have contact with a diagnosis that they will not likely see in the developing world unless a bioterrorism event occurs.
* If an anthrax attack does occur, then physician familiarity with anthrax infection may be lifesaving for patients.
Medical simulation has become a standard tool in many medical education programs. Bioterrorism events are rare but potentially catastrophic, and medical simulation provides an opportunity to teach capabilities in the diagnosis and management of these events. This article describes the use of a high-fidelity simulator as the patient, but some educators may prefer a standardized patient.
What Is Medical Simulation?
The use of medical simulation has increased dramatically in the past decade. Medical simulation adapts technology to the educational environment and provides a mechanism to rehearse critical patient care events. Aspects of learning that may carry risks for patients at the bedside can now be moved to a laboratory environment.1
As stated by the Accreditation Council for Graduate Medical Education Bulletin Editor Ingrid Philibert, “Budding and experienced musicians, actors, lawyers giving closing arguments, clergy preparing sermons… would not consider engaging in these activities without some form of rehearsal, either as an explicit trial of the activity in a ‘low-stakes’ setting, or at least as a deliberate ‘mental walk-through’ of all the steps that will go into the actual performance.”1 Simulation-based medical education may allow consistent trainee exposures to unusual medical conditions, critical incidents, near misses, and crises.2
Simulation has been used unsystematically for centuries.3 In the 16th century mannequins, referred to as “phantoms,” were developed to teach obstetric skills.4 Current high-fidelity simulators involve human-shaped mannequins with electronically controlled parameters. These simulators actively depict both normal and abnormal pulses, pupillary examinations, cardiac sounds, pulmonary sounds, and other parameters depending on the individual mannequin’s design and capabilities. Advanced simulation-based medical education can provide realistic representations of patient care issues and clinical environments (Fig. 1).
Educators can alter simulated patient reactions and responses in ways that are not possible with actual patients, and this can increase the precision and relevance of training and competency assessment.5 With medical simulation, trainees are able to have their first contact with real patients, and practicing clinicians can use medical simulation to improve their proficiency when learning new procedures or when developing their existing skills.
Simulation is an important tool for improving the safe delivery of medical care. Medicine, however, has lagged behind other high-technology and high-risk professions such as aviation in the use of simulators. The possible reasons for this delay include cost, limits to the accurate modeling of complex human pathophysiology, demands for rigorous scientific evidence of effectiveness, and resistance to change.2 Medical trainees need live patients to hone their professional skills, and this requirement could at times have an impact on patient safety. Simulation-based learning can develop health professionals’ knowledge, skills, and attitudes while protecting patients from unnecessary risk.2
The use of medical simulation in residency training programs has been well described across multiple disciplines,6–8 and the effectiveness of simulation-based training in disaster preparedness also has been described.9–14 Learning from errors is a key component in improving expertise; future behaviors are changed as a result of this experience.15 Mistakes made during simulation exercises are more easily exposed and discussed than mistakes involving actual patients. In a simulation environment, instructors can actually provoke errors, allowing trainees the opportunity to cope with desired conditions. Simulation protocols can involve actors posing as family members of the simulated patient. Trainees can be taught and evaluated on their approach in dealing with the families of the simulated patients.2
Disaster training comparisons of high-fidelity simulators versus trained actors in a simulation disaster have been undertaken. One study demonstrated that high-fidelity simulators, when compared to live actor-patients, have equivalent results in prompting critical actions in mass casualty drills, and increased perceived reality of the exercises also was noted.16
During the response to a bioterrorism attack, meaningful communication must involve the right information delivered at the appropriate time in an effective manner from trusted sources. A simulation model of the hypothetical response to anthrax bioterrorism indicated that predicted mortality increases significantly the longer the amount of time from the attack’s detection to its announcement. Timeliness, accuracy, and precision of communication, in addition to instructions for obtaining prophylaxis and treatment, are critical.17
Anthrax as a Disease and as a Bioterrorism Agent
The first modern experience with aerosolized anthrax pertains to 42 deaths accidental release of material in Sverdlovsk, Russia, in 1979.18 The deaths resulted from the inhalational form of anthrax after a 1- to 4-day illness, which occurred several days after exposure. The first reported use of anthrax as a bioterrorism agent occurred in the United States, the autumn 2001 attacks in which 22 cases and 5 fatalities were reported. Half of the cases were inhalational and half were cutaneous.19 Jernigan et al described 10 of the inhalational anthrax cases.20 Seven of the victims were postal employees, and the median age of the patients was 56 years (range 43–73 years). The median incubation period from the time of exposure to onset of symptoms was 4 days (range 4–6 days). Symptoms included fever or chills (n = 10), sweats (n = 7), fatigue or malaise (n = 10), nausea or vomiting (n = 9), and dyspnea (n = 8).20 Cough was minimal or nonproductive in nine of the subjects, and all of the patients with inhalational anthrax had abnormal chest x-rays. The abnormalities included infiltrates, pleural effusions, and mediastinal widening.
Patients sought care a median of 3.5 days (range 1–7 days) after the onset of symptoms. Eight of the patients were in the initial phase of illness when they first sought care; six of them received antibiotics with activity against Bacillus anthracis and all survived. Four patients who had fulminant disease when they received their antibiotics died. Pleural effusions were a consistent clinical feature and occurred in all of the patients.20 Evaluation of these first 10 inhalational cases reported suggests that survival may be markedly improved by the combination of antimicrobial therapy begun during the initial phase of the illness along with aggressive supportive care such as drainage of pleural effusions.20
Historically, naturally acquired inhalational anthrax has been described as having a presentation of an initial 1 to 4 days of malaise, fatigue, fever, myalgias, and nonproductive cough, which is then followed by a fulminant phase of dyspnea, cyanosis, and profuse diaphoresis.21 In the initial phase of the 2001 anthrax outbreak, patients experienced profound and often drenching sweating and nausea and vomiting. Abnormalities on initial chest x-rays included mediastinal widening, paratracheal fullness, hilar fullness, pleural effusions, and parynchemal infiltrates. The total white blood cell count was normal or only slightly elevated at the time of initial visit in these patients.20
Inhalational anthrax occurs 2 to 43 days after exposure in humans.22 The bacteria multiply and produce exotoxins that quickly cause mediastinal edema and necrosis. These conditions can be followed by bacteremia, toxemia, and sepsis, which subsequently cause death. Inhalational anthrax is therefore bimodal; a nonspecific prodromal period is followed by a fulminant course.
During the prodromal period, inhalational anthrax may be difficult to distinguish from pneumonia or influenza. In cases of anthrax, the presenting complaints include nausea, vomiting, pallor/cyanosis, diaphoresis, altered mental status, tachycardia >110 beats/min, a temperature >100.9°F, and an increased hematocrit.23,24
Because the first symptoms of inhalational anthrax are nonspecific, the diagnosis requires a high degree of suspicion. After the incubation period, patients may have dyspnea, cough, headache, chills, vomiting, weakness, or chest pain,20 and many of these symptoms were prevalent in the 2001 anthrax attacks. Physical examination findings included fever, tachycardia, and hypoxemia. Early treatment with two or more antimicrobial agents, one of which is either ciprofloxacin or doxycycline, may improve the survival in people exposed to anthrax.
Cutaneous anthrax is the most common form of the naturally acquired anthrax contagion; approximately 2000 cases are reported worldwide each year. None of the cutaneous cases of anthrax diagnosed in 2001 attacks were fatal.19 With treatment, <1% of cutaneous anthrax cases should be fatal, whereas data from before the antibiotic era show that 10% to 40% of untreated patients with cutaneous anthrax may die from exposure. A well-developed anthrax lesion can be recognized easily by a physician familiar with the disease; unfortunately, few physicians in developed countries have ever seen this clinical picture.25
Gastrointestinal anthrax results from the ingestion of bacilli from undercooked meat and, to the author’s knowledge, has not been used as a bioterrorist weapon, although autopsy results from Sverdlovsk revealed hematogenously spread gastrointestinal anthrax in victims who died of inhalational anthrax.18
The challenge of identifying anthrax is illustrated by an Israeli study that assessed the ability of emergency departments (EDs) to make an accurate diagnosis.26 Biologic drills were instituted and hospital and emergency physician managers were informed at the beginning of the calendar year that a drill using a surrogate patient with a clinical picture of inhalational anthrax would occur at some point, although the exact date for each hospital was not announced.26 Surrogate patients presented with symptoms consistent with anthrax. They complained of a dry cough, chest tightness, pleuritic pain, shortness of breath, myalgia, nausea, headache, and drenching sweats. These patients induced a factitious elevated oral temperature using a warm liquid. As part of the drill, chest x-rays consistent with anthrax infection were provided to the ED staff as replacements for the x-rays taken of the surrogate patients. The ED staff admitted 91% of the surrogate patients and included anthrax in the differential diagnosis 61% of the time. Only 43% of institutions notified relevant local and state officials.26
Pregnant women and their infants are thought to be more vulnerable to bioterrorism than other population groups.27–29 Ciprofloxacin is the first-line drug prophylaxis for women exposed to anthrax; however, the prophylactic treatment of pregnant or lactating women should be limited to those exposed to a high-risk source of contamination. Few controlled studies have been conducted on the use of ciprofloxacin in pregnancy, but the morbidity and mortality of anthrax clearly outweigh the risk of ciprofloxacin.30 Prophylaxis for asymptomatic pregnant or lactating women is 500 mg of ciprofloxacin orally every 12 hours for 60 days. If the anthrax bacteria are found to be sensitive to penicillin, then the patient can be switched to amoxicillin.30
Anthrax as a Teaching Model for Disaster Preparedness
The first potential healthcare providers to come in contact with victims of an anthrax attack include family physicians, ED physicians, pediatricians, internal medicine physicians, and obstetrician/gynecologists. Given the lack of familiarity of medical students and obstetrician/gynecologist trainees with an anthrax diagnosis, the author established a residency program medical simulation educational format at East Tennessee State University in 2005 (anthrax is one of many scenarios taught in the program). Crisis management has been an important component of this simulation program. Residents and medical students do not know the diagnosis before they begin participation in the scenario. For this exercise, a patient simulator presented symptoms of both cutaneous and inhalational anthrax. Although it is understood that none of the patients in the 2001 anthrax attack had both forms, it was believed that combining the clues could be appropriate for the trainees’ educational level. The moulage on the mannequin’s hand to simulate the anthrax lesion is shown in Fig. 2; the trainees also may be shown a picture of an actual anthrax lesion. In this exercise, the lesion is usually covered by a bandage that the learners must remove to examine. It is interesting to note that medical student learners have noticed the bandage but have failed to look under it until prompted. This is an opportunity for them to learn about thoroughness when performing a physical examination.
In the author’s experience, trainees appreciate the opportunity afforded by the simulation laboratory and exposure to infections with which they are unfamiliar. Trainees are advised that patients in the simulation laboratory have a higher mortality rate than in the general population. This is certainly the case with the anthrax scenario in that the diagnosis usually is missed. Thus far, only residents given a patient with both cutaneous and inhalational anthrax have made a successful diagnosis, and this observation highlights the value of the exercise.
The Table is the instructor’s template for the scenario run and is the suggested tool for educators who wish to use it when training medical personnel. A previous version of the Table has been published elsewhere.31
Table Assessment too...Image Tools
Bioterrorism threats will remain a concern for the healthcare system for the foreseeable future. In the case of anthrax, early diagnosis can be lifesaving for exposed patients and can allow for the rapid implementation of protocols to protect the community at large. Simulation has been shown to be an educational format superior to lecture. The use of a simulation-based educational program to prepare healthcare providers and healthcare systems for bioterrorism events such as anthrax has the potential to significantly improve outcomes for future bioterrorism victims and the communities in which they reside.
Mr Jake Drumm, simulation laboratory technician at East Tennessee State University, created the moulage in Fig 2. His contributions to the medical simulation education of obstetrics/gynecology residents and students have been noteworthy. Ms Patti Davison, obstetrics/gynecology residency coordinator, has cheerfully played the role of “voice of the simulator” in numerous scenarios. Her creativity has been of inestimable value in the creation and management of the simulation program for the Department of Obstetrics and Gynecology at East Tennessee State University.
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