Study design
This pilot study was designed for first-year medical students as part of an optional activity from their basic science curriculum. The study 2015E0170 was reviewed by our Institutional Review Board (Office of Responsible Research Practices-The Ohio State University), and approved as an exempt study with informed consent waiver due to the observational nature of the study. All enrolled students who participated in the supplemental HFS session of pulmonary physiology were allocated to the simulation group. Four sessions per day were offered during one week in April 2014. Each session was limited to eight medical students. The remaining students who did not volunteer to participate in the pilot HFS sessions were allocated to the LBE group.
Population and setting
First-year medical students from The Ohio State University, College of Medicine who were participating in a pulmonary curriculum block were offered to participate in an extracurricular and supplemental learning session of the pulmonary physiology system using HFS. Recruitment was done on a voluntary basis. Students were told about the simulation sessions through announcements in class and by email and were provided with a schedule link in Google Docs or in person at the Office of Medical Education where they were able to sign up for the sessions. MCAT scores were collected and compared between groups to assess academic baseline characteristics.
Simulator sessions
The faculty instructors in charge of this pilot study created a novel 75 minute session with multiple case scenario simulations that included three separate 25 minute stations each simulating different phases of patient care which highlighted basic pulmonary concepts and physiology. Students started with a basic pulmonary physical examination and progressed to interpretation of external and invasive hemodynamic monitoring to integrate basic science concepts with clinical applications.
The first station took place in the simulation center hallway; this was a trauma scene involving an unresponsive patient lying on the floor. The patient was portrayed by a Laerdal SimMan® 3G manikin. At this station, students were taught how to evaluate the pulmonary function of the patient without medical equipment.
The second station was a simulated emergency room trauma bay; the trauma patient was portrayed by a CAE Healthcare HPS® manikin. Medical students were taught how to properly place and read the monitors to assess the pulmonary system. The manikin was preprogrammed to simulate clinical scenarios of tension pneumothorax, a right-mainstem intubation and atelectasis. With the aid of the electronic SMART board, topics such as oxygenation, the alveolar gas equation, ventilation/perfusion (V/Q) mismatch (shunt), and lung volumes were explained. Following the clinical scenario, medical students were given the opportunity to treat the patient as they would in a real clinical environment.
The third station was a simulated intensive care unit (ICU) where the patient was portrayed using a Laerdal SimMan® 3G manikin. In the ICU, the focus was mainly on the principles of ventilation, dead space, and the West zones of the lung. Three faculty instructors mentored the medical students through the three scenarios, with one being present at each station. At each station, the faculty instructor described the setting and guided the student participants through the patient case. Rather than one debriefing session at the end of the clinical scenario, briefer “time outs” were conducted throughout the case scenario in order to reinforce the important learning objectives and to offer time for questions and clarifications.
During the time-outs, students were given the opportunity to process test results or data on the patient’s condition from the monitors. Questions from the instructor helped the students to interpret the data and make patient management decisions based on their interpretations. A confederate person that represented a health care provider was also present during the three scenarios. The confederate’s primary role was to assure the chronological changes in the patient’s status according to the evolution of the case and alert medical students regarding undetected changes. In addition, a simulator operator was also sitting behind a two-way glass and was responsible for performing the mechanical changes on the simulator according to the scripts and cues from the faculty facilitator.
Intervention assessment
The pulmonary simulation sessions took place approximately five weeks prior to the final examination over the cardio-pulmonary curriculum block. At the end of the block, students took their curricular test consisting of 49 items covering anatomy, physiology, and pathophysiology of the cardio-pulmonary system. An overall cardio-pulmonary score was compared between SBE and LBE students. A separate score for the pulmonary physiology section was also compared between groups. Furthermore, faculty reviewed the test and identified six topics which specifically assessed the objectives of the implemented HFS pulmonary physiology scenarios. These six topics were stratified and scored separately from the overall test score and compared between groups. Raw scores on these items were converted to percentage correct scores.
Additionally, at the conclusion of each session, medical students from the simulation group completed an anonymous eight-point Likert scale satisfaction survey in order to assess their perception of the utility of the HFS session.
Data analysis
Test scores and survey responses were summarized using descriptive statistics. Test scores, which were not normally distributed, were expressed using medians and interquartile range (IQR) and survey responses were expressed using frequencies and proportions. To evaluate student performance at the end of unit examination, comparisons in test scores between SBE group and LBE group were assessed using descriptive statistics as well as a Kruskal-Wallis test, where appropriate. Statistical analysis was performed using SAS/STAT statistical software (version 9.4 of SAS for Windows, SAS Institute Inc., Cary, NC).