Gradual and Discrete Ontogenetic Shifts in Rattlesnake Venom Composition and Assessment of Hormonal and Ecological Correlates.

Ontogenetic shifts in venom occur in many snakes but establishing their nature as gradual or discrete processes required additional study. We profiled shifts in venom expression from the neonate to adult sizes of two rattlesnake species, the eastern diamondback and the timber rattlesnake. We used serial sampling and venom chromatographic profiling to test if ontogenetic change occurs gradually or discretely. We found evidence for gradual shifts in overall venom composition in six of eight snakes, which sometimes spanned more than two years. Most chromatographic peaks shift gradually, but one quarter shift in a discrete fashion. Analysis of published diet data showed gradual shifts in overall diet composition across the range of body sizes attained by our eight study animals, while the shifts in abundance of different prey classes varied in form from gradual to discrete. Testosterone concentrations were correlated with the change in venom protein composition, but the relationship is not strong enough to suggest causation. Venom research employing simple juvenile versus adult size thresholds may be failing to account for continuous variation in venom composition lifespan. Our results imply that venom shifts represent adaptive matches to dietary shifts and highlight venom for studies of alternative gene regulatory mechanisms.

Use of human patient simulation and validation of the Team Situation Awareness Global Assessment Technique (TSAGAT): a multidisciplinary team assessment tool in trauma education.

OBJECTIVE: Situation awareness (SA) is a vital construct for decision making in intense, dynamic environments such as trauma resuscitation. Human patient simulation (HPS) allows for a safe environment where individuals can develop these skills. Trauma resuscitation is performed by multidisciplinary teams that are traditionally difficult to globally assess. Our objective was to create and validate a novel tool to measure SA in multidisciplinary trauma teams using a HPS--the Team Situation Awareness Global Assessment Technique (TSAGAT). SETTING: Memorial University Simulation Centre. DESIGN/PARTICIPANTS: Using HPS, 4 trauma teams completed 2 separate trauma scenarios. Student, junior resident, senior resident, and attending staff teams each had 3 members (trauma team leader, nurse, and airway manager). Individual SAGATs were developed by experts in each respective field and contained shared and complimentary knowledge questions. Teams were assessed with SAGAT in real time and with traditional checklists using video review. TSAGAT was calculated as the sum of individual SAGAT scores and was compared with the traditional checklist scores. RESULTS: Shared, complimentary, and TSAGAT scores improved with increasing team experience. Differences between teams for TSAGAT and complimentary knowledge were statistically significant (p < 0.05). Mean checklist differences between teams also reached statistical significance (p < 0.05). TSAGAT scores correlated strongly with traditional checklist scores (Pearson correlation r = 0.996). Interrater reliability for the checklist tool was high (Pearson correlation r = 0.937). CONCLUSION: TSAGAT is the first valid and reliable assessment tool incorporating SA and HPS for multidisciplinary team performance in trauma resuscitation. TSAGAT could compliment or improve on current assessment methods and curricula in trauma and critical care and provides a template for team assessment in other areas of surgical education.

Trauma education and assessment.

Trauma education has evolved over the past 30 years from an unstructured preceptorship to standardised courses offered worldwide. The Advanced Trauma Life Support (ATLS) course has formed the backbone of trauma management philosophy and has spawned a series of courses aimed at specific patient populations and health care groups. Trauma education and assessment for advanced trainees has taken the form of formal clinical fellowships. In addition to clinical experience, a number of tools have been validated in aiding trauma education including use of videotape review and simulation technology. Future emphasis on development and validation of teaching and assessment techniques could improve trauma education and secondarily impact trauma outcomes worldwide.

Use of human patient simulation and the situation awareness global assessment technique in practical trauma skills assessment.

BACKGROUND: Situation awareness (SA) is defined as the perception of elements in the environment within a volume of time and space, the comprehension of their meaning, and the projection of their status in the near future. This construct is vital to decision making in intense, dynamic environments. It has been used in aviation as it relates to pilot performance, but has not been applied to medical education. The most widely used objective tool for measuring trainee SA is the Situation Awareness Global Assessment Technique (SAGAT). The purpose of this study was to design and validate SAGAT for assessment of practical trauma skills, and to compare SAGAT results to traditional checklist style scoring. METHODS: Using the Human Patient Simulator, we designed SAGAT for practical trauma skills assessment based on Advanced Trauma Life Support objectives. Sixteen subjects (four staff surgeons, four senior residents, four junior residents, and four medical students) participated in three scenarios each. They were assessed using SAGAT and traditional checklist assessment. A questionnaire was used to assess possible confounding factors in attaining SA and overall trainee satisfaction. RESULTS: SAGAT was found to show significant difference (analysis of variance; p < 0.001) in scores based on level of training lending statistical support to construct validity. SAGAT was likewise found to display reliability (Cronbach's alpha 0.767), and significant scoring correlation with traditional checklist performance measures (Pearson's coefficient 0.806). The questionnaire revealed no confounding factors and universal satisfaction with the human patient simulator and SAGAT. CONCLUSIONS: SAGAT is a valid, reliable assessment tool for trauma trainees in the dynamic clinical environment created by human patient simulation. Information provided by SAGAT could provide specific feedback, direct individualized teaching, and support curriculum change. Introduction of SAGAT could improve the current assessment model for practical trauma education.