Medical Simulation-Based Learning Outcomes in Pre-Clinical Medical Education.

Introduction Medical simulation is widely used in the United States medical curriculum. However, learning outcomes based on simulation have yet to be reported. In this study, we aim to characterize the objective performance of first- and second-year medical students following eight weeks of medical simulation-based learning. Methods First- (n=25) and second-year (n=15) medical students were recruited for this study. We designed and administered a novel pre-experience examination to collect participant demography and assess simulation and non-simulation knowledge. Following 14 high-fidelity simulation scenarios over the course of eight weeks, we administered an identical post-experience examination and compared performance, primarily using a within-subjects analytic design. Results Student performance improved by an average of 18% following the medical simulation experience, and first-year students demonstrated greater benefit (22%) as compared to second-years (12%). Relative to first-years, second-year students showed higher overall performance on both pre- and post-examination. Demographic factors and prior medical experience were not significantly associated with assessment performance and score improvement. Conclusions Our data supported the efficacy of simulation-based learning as evidenced by the significant improvement in objective performance on a standardized examination. That is, both first- and second-year medical students demonstrated test-score improvement following an eight-week medical simulation program. Of note, the first-year students exhibited greater benefit (at the group level). Importantly, these findings were statistically unrelated to participant demographic and background variables. Collectively, this study provides preliminary evidence that medical simulation in the pre-clinical phase of undergraduate medical education is an effective tool for student learning.

Single-pass environmental chamber for quantifying human responses to airborne chemicals.

Despite increasing interest in the short-term effects of airborne environmental contaminants, experimental findings are generated at a very slow pace. This is due in part to the expense and complexity of most environmental chambers, which are needed for quantifying effects of wholebody exposures. We lessened this obstacle by designing, constructing, and testing a single-pass, 10-m3 stainless-steel chamber. Compressed air is purified before being sent to an air dilution olfactometer, which supplies 1000 L (1 m3) per minute (referenced to STP) while maintaining 40% relative humidity (RH) and 22.6 degrees C. Precise control of all stimulus parameters is greatly simplified since air is not recirculated. Vapor-phase odorant concentrations are achieved by varying the proportion of total airflow passing through one or more saturators, and are verified in real time by an infrared (IR) spectrometer. An adjoining 5-m3 anteroom is used for introducing known intensities of more chemically complex vapor and/or particulate stimuli into the chamber. Prior to the point that air is exhausted from the chamber, all components are made of stainless steel, Teflon, or glass. A LabView program contains feedback loops that achieve document chamber conditions and document performance. Additional instrumentation and computer systems provide for the automated collection of perceptual, respiratory, eye blink, heart rate, blood pressure, psychological state, and cognitive data. These endpoints are now being recorded, using this facility, in response to ranges of concentrations of propionic acid and environmental tobacco smoke.

Human odor detectability: new methodology used to determine threshold and variation.

Current ambiguity concerning the related issues of optimal means for measurement of odor sensitivity and the functional properties of the olfactory system hinders progress in basic and applied research on the human sense of smell. To address these needs, we selected n-amyl acetate (nAA) as a test odorant and developed a methodology in which participants (Ps) receive multiple presentations each session of several concentrations. Yes-no responses as to whether odor was detected are analyzed using binomial statistics, with the probability that a given proportion of yes responses (or greater) would occur by chance alone being treated as the inverse of detectability. Over the course of multiple sessions, this information is also used to maximize the collection of data in the peri-threshold region. Surprisingly, data collected over as many as 14 sessions were fit well by a single logistic regression model relating probability and concentration. Threshold concentrations, defined as those corresponding to a probability of 0.05, varied from 7.11 to 167.53 p.p.b. (v/v) for 11 Ps. Our approach and findings, if shown to be representative of other combinations of Ps and odorants, could accelerate the pace of research in human olfaction by providing a comprehensive operational definition of the limit of the olfactory system to detect odorant molecules.