New methods of Early Surgical Training Using the Human-Worn Partial Task Surgical Simulator in Scenario-Based Stress-Immersion Training

A delicate balance exists between a beneficial stress response that enhances memory and recall and a detrimental high stress response that impairs the ability to perform learned skills.  A week-long Intensive Surgical Skills Course at Rocky Vista University College of Osteopathic Medicine is using a ground-breaking surgical simulator to improve learning outcomes in high-pressure situations while mitigating negative stress effects.

Attention, decision-making, and response time of medical personnel are compromised under high levels of stress, but can be reduced with appropriately learned coping skills.  Repetitive training in stressful situations enables people to override the negative effects of stress, optimizing performance under challenging conditions.1 This is particularly true for medical students as they develop advanced skills during early exposures to surgery and emergency medicine in their third and fourth-year clinical rotations.  The stress of these exposures can be lessened by a firm grasp of basic procedures and surgical technique.  Reducing the stress to a beneficial level is critical to effective learning.  Ultimately, improved medical student training leads to improved safety and quality of patient care in hospital settings and especially in austere combat settings experienced by military physicians.

Background

Rocky Vista University College of Osteopathic Medicine (RVU), in Parker, Colorado, has over 100 Army, Navy, and Air Force students enrolled through the Health Professions Scholarship Program (HPSP).  This represents the largest population of military medical students outside the Uniformed Services University of the Health Sciences in Bethesda, Maryland.  The Military Medicine Honors Track (MMHT) at RVU is a distinctive medical school program that is tailored to the unique careers of military physicians.  This year, the MMHT curriculum for second-year medical students (MS2) concluded with a week-long Intensive Surgical Skills Course (ISSC) that sought to better prepare students for clinical rotations through hyper-realistic scenario-based stress-immersion training with the use of a new surgical simulator, the Human-Worn Partial Task Surgical Simulator (“Cut Suit”).  The ISSC reduced stress and improved performance in RVU’s HPSP MS2s, benefiting not only the students’ acquisition of skills and knowledge, but also increasing the quality of patient care.

Strategic Operations, Inc. (STOPS) initially developed the Cut Suit for Tactical Combat Casualty Care (TCCC) training and later as a surgical simulator for medical education.  Individual components of the Cut Suit simulate the organs of the thoracic and abdominal cavities, neck, and proximal lower extremities.  A Kevlar shield behind the simulated organs protects the wearer from surgical instruments.  The Cut Suit is complete with organs, vessels that bleed, accurate odors, and an outer layer of skin.

Training scenarios utilizing the Cut Suit provide the realistic stress of performing procedures on a live patient, whether in a simulated battlefield, emergency department (ED), or operating room (OR).  All organs and the skin can undergo repeated simulations of open operations and lifesaving procedures.  For example, a penetrating abdominal trauma can be opened to reveal bleeding and injured bowel, the appropriate vessel and bowel repairs can be made, the skin can be closed, and all organs and skin involved can then be repaired and reset with the pathology of the next training case.  The Cut Suit facilitates learning and management of common causes of preventable death on the battlefield, including tourniquet application and arterial ligation/clamping in extremity hemorrhage, surgical cricothyroidotomy for airway control, needle decompression and tube thoracostomy for pneumothorax.2-3

The Cut Suit (Human-Worn Partial Task Surgical Simulator) prior to the skin covering put on (left), and after skin and uniform are put on. Image Credit: Rocky Vista University.

Design

The Cut Suit fills a major gap in simulation technology by providing a training model for open surgical procedures.  Students learn surgical techniques of organ exploration, repair and resection, hemorrhage control, suturing and stapling organs and skin on a model with accurately represented pathology, bleeding, and surgical diseases’ smells.

The week-long ISSC enrolled twenty-two HPSP students at the end of the MS2 year.  A hyper-realistic simulated ED saw 40 patient scenarios, encompassing commonly seen cases ranging in acuity from respiratory infections to acute cholecystitis and traumatic burns.  Students alternated playing the roles of patients and emergency medicine (EM) residents.  After performing histories and physicals and ordering appropriate labs and imaging (prepared test results were provided by the patient), patients were triaged for ED management or surgical intervention.  The EM resident presented the case to the EM attending physician and proceeded accordingly.

If the patient required surgery, the patient was taken to the hyper-realistic OR while wearing the Cut Suit.  Another student acting as surgical resident was first assistant to the attending physician during the operation performed on the Cut Suit.  Surgical procedures included appendectomy, cholecystectomy, tumor resections, splenectomy, penetrating abdominal trauma, control of hemorrhagic liver, tube thoracostomy, thoracotomy and exploratory laparotomy for traumatic rupture of the aorta.

During OR cases, all students were present, either assisting or observing, and were expected to be prepared to discuss all aspects of the case the following day during morning report.  Both the ED and the OR hyper-realistic scenarios were overseen by the corresponding attending physicians who contributed to creating accurate levels of stress.  Students perceived stress and confidence levels were tracked daily with student surveys.

The Cut Suit provides a model for simultaneous assessment of technical and non-technical skills required of surgical teams.4  Technical skills include suturing, instrument tying, two-hand knot tying, peripheral IV access, tube thoracostomy, and surgical cricothyroidotomy.  Non-technical skills include teamwork, effective and respectful communication, leadership, and performance under stress.

Students received didactic and functional instruction in surgical instruments identification throughout the week.  Education in pathophysiology and management of surgical disease was achieved through student presentations on assigned topics.  Knowledge of surgical instruments and surgical disease, were assessed by a written pre-test examination the first day and a post-test on the final day of the ISSC.

Outcomes

The impact of stress on learning was evaluated through daily surveys in which students reported their perceived stress level in each training component, total overall perceived stress level, perceived impact of stress on learning, and overall confidence for task performance (Table 1).  Throughout the ISSC, we observed an inverse relationship between stress and confidence.  With each day of exposure to stressful training scenarios, students reported feeling incrementally less stressed and more confident.

Table 1.  Weighted average of all students’ daily self-reported

We utilized 360° evaluations adapted from the ACGME Competencies and Toolbox of Assessment Methods5 to evaluate the non-technical proficiencies of students.  Non-technical skills were evaluated by peers in both patient and co-worker roles, and by attending physicians (Table 2).  A 1-5 rating scale assessed five non-technical skills: teamwork, effective communication, respect of co-workers and patients, facilitation of knowledge, and leadership skills.  Students’ ratings increased each day of the ISSC, showing improvement in non-technical skills.

Table 2.

Technical skills evaluated during the ISSC included suturing, instrument tying, two-hand knot tying, peripheral IV access, tube thoracostomy, and surgical cricothyroidotomy.  For each of these measures, students were given a pass/fail practical examination on the first day of the ISSC and again on the final day (Table 3).

Table 3. Technical Skill Evaluation

Students received both didactic and functional instruction in identifying surgical instruments throughout the ISSC, with a fill-in-the-blank pre-test and post-test evaluation (Table 4).  In comparison to the pre-test scores and to the scores of a control group of 22 third-year students (MS3) who took the same instrument exam after completing the required four-week general surgery core rotation, the post-test scores show that the ISSC prepared students to be a functional member of an OR team by understanding instrumentation, significantly exceeding the preparation achieved in core MS3 rotations.

Table 4.  Individual Surgical Instrument Identification

A written examination covering pathophysiology and management of surgical disease, as taught through student presentations, was given as a pre-test and post-test (Table 5).  A modest yet statistically significant improvement in scores was observed (paired t-test, p < 0.0025) in the pre-test average (43.0%) versus post-test average (49.3%).

Table 5.  Individual pre-test (Day 1) and post-test (Day 5)

Discussion

The data we collected supports our hypothesis of improved confidence and technical and non-technical proficiencies from training under stress with hyper-realistic surgical simulators.  We anticipate administrating the ISSC for second-year military students each year, as well as collaborating with other medical schools nationally to standardize the course for use on a broader scale.

However, aspects of the ISSC need continuing development.  To complete the data set of our first course, we will be following board scores of participating MS2s, as well as objective (shelf exam scores) and subjective (preceptor evaluations) measures of their performance on MS3 general surgery rotations, all of which will be compared to control sets of students who were not enrolled in the ISSC.

Additionally, because of its preliminary nature, the ISSC was rapidly evolving during the week’s planning stages.   As a result, not all of our evaluation metrics were maximally aligned to reflect the course objectives and offerings.  Therefore, we will improve the metrics to more closely reflect objectives in future courses by doing the following:

A student wears the Cut Suit while presenting as a patient with extremity hemorrhage in need of treatment. Image Credit: Rocky Vista University.

Going forward, our primary metrics will be the STAI for baseline and training stress evaluation, a revised 360° evaluation that incorporates the patient perspective, a more comprehensive technical skill evaluation, continued use of the surgical instrument exam, and long-term follow-up evaluation of participating students as they progress in medical training.  Additionally, a control group of students involved in the traditional medical school curriculum but not the ISSC will be incorporated.

Conclusion

The ISSC at RVU is the first medical school program to use the new open surgical simulator, the Cut Suit, in hyper-realistic stress-immersion training to improve second-year military medical student preparedness to overcome the negative effects of stress during medical education and practice.  While there are ways that we plan to improve the ISSC, the initial outcomes show clear improvement in all metrics.  This provides support for expanding this training at our medical school and in collaboration with other medical schools and residency programs throughout the nation.

References

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2. Bellamy R. (2007) A note on American combat mortality in Iraq. Military Medicine 172(10):1023.
3. Holcomb J, Stansbury L, Champion H, Wade C, & Bellamy R. (2006) Understanding combat casualty care statistics. The Journal of Trauma: Injury, Infection, and Critical Care 60(2):397-401.
4. Arora S, Sevdalis N. (2010) The impact of stress on surgical performance: a systematic review of the literature. Surgery 147:318-330.
5. Swing S, Bashook P. (2000) ACGME/ABMS joint initiative toolbox of assessment methods. ACGME Outcomes Project. Version 1.1:1-19.
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