A disaster medicine course for Canadian medical students: first implementation of a large-scale mass-casualty simulation.

Mass-casualty incidents have a significant global impact. Despite calls for improved disaster-preparedness training, most medical curriculums do not include formal disaster-medicine education. In 2021, the Medical Council of Canada introduced new disaster-medicine learning objectives. This article presents a mass-casualty-incident course for 3rd-year Canadian medical students. The course includes lectures, and a large-scale simulation of an explosion scene, field triage zone, and simulated emergency department (ED). The simulation incorporated "Dark-team-member" facilitators and 17 live actor and 8 mannequin patients with moulage. Pre-/post-event evaluation data was collected. One-hundred and twenty medical students participated in the course. Confidence in managing a real mass-casualty incident, on a scale from 1 to 10 (no-confidence to completely confident) significantly improved based on a Mann-Whitney U test, p < 0.05. Few formal medical student mass-casualty-incident courses exist. Combining "Dark-team-members" with live actors, imbedding clinician facilitators with medical students, and having a simulation with a continuous disaster scene to the ED are unique to this course. The methodology is presented for future replication.

RéSUMé: Les incidents faisant de nombreuses victimes ont un impact mondial significatif. Malgré les appels à l'amélioration de la formation à la préparation aux catastrophes, la plupart des cursus médicaux n'incluent pas de formation formelle à la médecine des catastrophes. En 2021, le Conseil médical du Canada a introduit de nouveaux objectifs d'apprentissage en médecine de catastrophe. Cet article présente un cours sur les accidents de masse destiné aux étudiants en médecine canadiens de troisième année. Le cours comprend des cours magistraux et une simulation à grande échelle d'une scène d'explosion, d'une zone de triage sur le terrain et d'un service d'urgence (SU) simulé. La simulation comprenait des facilitateurs "Dark-team-member" et 17 acteurs réels et 8 patients mannequins avec moulage. Des données d'évaluation avant/après l'événement ont été collectées. Cent vingt étudiants en médecine ont participé au cours. La confiance dans la gestion d'un véritable incident de masse, sur une échelle de 1 à 10 (aucune confiance à une confiance totale), s'est améliorée de manière significative d'après un test U de Mann-Whitney p<0,05. Il existe peu de cours formels sur les accidents de masse à l'intention des étudiants en médecine. La combinaison de " Dark-team-member " avec des acteurs en chair et en os, l'intégration d'animateurs cliniciens avec des étudiants en médecine et la simulation d'une scène de catastrophe continue au service des urgences sont des éléments uniques de ce cours. La méthodologie est présentée pour être reproduite à l'avenir.

Lateral-line neuromast development in Ambystoma mexicanum and a comparison with Rana pipiens.

We have examined the embryonic development of the major neuromast lines of the lateral-line system in the urodele Ambystoma mexicanum both in vivo (using microsurgical techniques to transplant placodes) and in preserved embryos using scanning electron microscopy (SEM). We have compared this to SEM observations of embryos of the anuran Rana pipiens. We have determined the approximate locations of the lateral-line placodes in A. mexicanum and the approximate timing of both the migration of the lateral line primordia and the neuromast eruption in both species. We find that, at hatching, all primary neuromasts are present and fully formed in Ambystoma, while migration of the primordia is just beginning in Rana. The neuromast systems in both species are fully formed by the time feeding begins. If neuromast eruption is considered in relation to developmental events other than hatching, fewer differences are found between species, suggesting that hatching is precocious in Rana. We find no evidence of heterochrony to account for the morphological differences observed in these lateral-line systems. Orthogonal neuromasts on the head, a derived feature of urodeles, appears to be the result of lateral neuromast movement subsequent to the rostral migration of the primordia. This process was not observed in the anuran. In addition, we observe that ciliated epidermal cells disappear from the area immediately around each of the lines and suggest that neuromasts cause the regression of cilia in their immediate vicinity.

Formation of the pronephros and pronephric duct rudiment in the Mexican axolotl.

In the Mexican axolotl (Ambystoma mexicanum), the pronephros begins to form at the four-somite stage. It is initially continuous with the posterior-lateral region of somite 2 and the lateral margin of somites 3 and 4. By the seven-somite stage, the pronephros has become compacted, and the cells are now morphologically distinct from the somitic cells. At this stage, a mass of loosely connected cells, apparently originating from the lateral mesoderm, is seen below somites 4 and 5. By the eight-somite stage, these presumptive duct cells have migrated dorsally to the duct path and are found below somites 5-7. By the nine-somite stage they have begun to migrate caudally.