The medical management of casualties in a chemical contaminated environment : a start for the CBRNE defence research program for clinicians

The main objective of this research program was to assess the status of clinical knowledge and evidence-based practice in the medical management of mass casualties, contaminated by exposure to a chemical weapon, during a medical evacuation, which is defined as from the incident site of a contaminated environment up-to a clean zone. First, in our published systematic review, we assessed past medical responses during a chemical attack. The lack of clinical data and intervention-related information, such as protection and decontamination capabilities, stresses not only the need to study acute or prehospital settings, but also a set of integrated competences in the contaminated environment (i.e.: protection, decontamination and clinical interventions) (Prospero registered CRD42019104473). Second, a method paper which presents an ongoing international retro-prospective observational study on the medical responses during a chemical attack has been submitted for publication. The goal of this study is to describe the acute clinical management of patients in the contaminated zone (1970-2036; US Clinical trial registered NCT05026645). Data gathering is currently ongoing with the use of a comprehensive online registry programmed by the Quebec Respiratory Health Research Network. In the third and fourth, we started the development of two technological innovations to improve the medical management of mass casualties, caused by a chemical weapon, in contaminated environments. The first is the creation of a mobile laboratory for the continuity of our work in both indoor and outdoor settings. The other is the launch of a research program, named VIMY Multi-System, which includes: (1) An electronic casualty card system integrating the United Kingdom National Early Warning System; (2) a forward-deployable telemedicine capability prototype – currently undergoing integration testing – that incorporates drone technology to monitor patients being clinically managed in a simulated chemically contaminated environment. Our fifth published paper, on the methods of oxygen conservation with an automated titration system (n= 60; US Clinical trial registered NCT02782936 and NCT02809807), showed that such an automated system may constitute a viable medical solution for interventions in a contaminated environment and also constitutes one of the possible solutions to improve therapeutic interventions. The system studied allows the maintenance of adequate oxygenation while reducing the use of oxygen in patients, making it possible to extend their treatment duration even under conditions of limited logistical resources in oxygen. The oxygen flow provided by the automated system allows a mean reduction in administered oxygen quantities of more than six-fold when decreasing the prescribed SpO2 target from 98 to 90% (5 L/min to1 L/min, p <0.001) in hospitalized patients with respiratory disorders. The comparison was conducted on the basis of conservative flow rate targets reported in the literature (2.5, 5.0, 10.0 and 15.0 l/min). When it comes to the automated correction of a hypoxemic condition in sick patients and healthy subjects wearing a gas mask, the prescribed SpO2 target resulted in maximum administered oxygen flow rates of 0.2 L/min and 2.9 L/min respectively. These results show a possible logistic and therapeutic optimization in the use of oxygen. Finally, these initial advances will be integrated as our research work progresses in order to improve clinical evidence-based practices in contaminated environments due to the use of chemical weapons.L’objectif principal de cette recherche était d’évaluer l’état des connaissances et le savoir-faire de la pratique clinique dans la gestion d’un grand nombre de blessés, contaminés des suites d’une exposition à l’arme chimique, pendant leur évacuation médicale depuis le site de l’incident dans un environnement contaminé jusqu’à la zone propre. Premièrement, dans une revue systématique que nous avons publiée, nous avons évalué les réponses médicales passées lors d’attaques chimiques. Le manque de données cliniques et d’autres informations liées à l’intervention, tel que les capacités de protection et de décontamination, souligne non seulement la nécessité d’étudier l’environnement préhospitalier, mais aussi la gamme de compétences interdépendantes en milieu contaminé (c.-à-d. : protection, décontamination et interventions cliniques) (Prospero CRD42019104473). Deuxièmement, nous avons soumis pour publication la méthodologie d’une étude rétroprospective observationnelle internationale s’intéressant aux réponses médicales lors d’une attaque chimique. Le but consiste à décrire la gestion clinique en soins aigus des blessés dans la zone contaminée (1970-2036) (ClinicalTrials.gov NCT05026645). L’acquisition de données est en cours à l’aide d’un registre de données intégral en ligne qui a été programmé par le Réseau de recherche en santé respiratoire du Québec. En troisième et quatrième lieu, nous avons entrepris le développement de deux innovations technologiques afin d’améliorer la prise en charge médicale des patients en milieu contaminé à la suite de l’utilisation de l’arme chimique. L’un est la création d’un laboratoire mobile pour poursuivre nos travaux tant à l’intérieur qu’à l’extérieur. L’autre est la mise sur pied d’un programme de recherche, nommé VIMY Multi-Systèmes, qui inclut : (1) un système de carte de blessés électronique intégrant le système national d’alerte précoce du Royaume-Uni, (2) les premiers tests d’intégration d’un prototype d’une capacité de télémédecine de déploiement avancé, incluant la technologie du drone, pour une surveillance clinique globale des patients pris en charge en milieu contaminé chimique simulé. Notre cinquième publication, qui porte sur les méthodes de maintien de l’oxygénation par titrage automatisée (n=60 ; ClinicalTrials.gov NCT02782936 et NCT02809807), nous a permis de démontrer qu’un système automatisé peut constituer une solution médicale intéressante qui serait applicable dans les interventions en milieu contaminé et de surcroît comme une solution pour améliorer les actions thérapeutiques. Le système que nous avons étudié permet de maintenir une oxygénation adéquate tout en limitant la consommation d’oxygène des patients, prolongeant ainsi leur durée de traitement, notamment en cas de ressources en oxygène limitées. D’une part, le débit de l’oxygène fourni par le système automatisé a permis une réduction moyenne des quantités administrées de l’ordre de plus de six fois lors de la diminution de la cible de saturation en oxygène (SpO2) prescrite de 98 à 90 % (5 L/min à 1 L/min, p < 0,001) chez les patients hospitalisés atteints de maladies respiratoires. La comparaison s’est faite par rapport à des débits conservateurs rapportés dans la littérature (2,5, 5,0, 10,0 et 15,0 L/min). D’autre part, la correction automatisée d’une condition hypoxémique chez les patients malades et les sujets sains portant le masque à gaz, la cible SpO2 a engendré des débits maximaux d’oxygènes administrés de 2,5 et 2,9 L/min respectivement. Ainsi, nous avons démontré une optimalisation logistique et thérapeutique de la consommation de l’oxygène. Finalement, ces premières avancées seront intégrées au fur et à mesure de l’avancement de nos recherches afin d’améliorer le processus de soins en milieu contaminé issu de l’utilisation de l’arme chimique

Natural succession and clearcutting as drivers of environmental heterogeneity and beta diversity in North American boreal forests

<div><p>Clear-cutting alters natural ecosystem processes by reducing landscape heterogeneity. It is the dominant harvesting technique across the boreal zone, yet understanding of how environmental heterogeneity and beta diversity are structured in forest ecosystems and post-clear cut is lacking. We use ground-dwelling arthropods as models to determine how natural succession (progression from deciduous to mixed to coniferous cover types) and clear-cutting change boreal forests, exploring the role of environmental heterogeneity in shaping beta diversity across multiple spatial scales (<i>between-cover types</i> and <i>between-stands of the same cover type</i> (1600 to 8500 m), <i>between-plots</i> (100 to 400 m) and <i>within-plots</i> (20 to 40 m)). We characterise environmental heterogeneity as variability in combined structural, vegetational and soil parameters, and beta diversity, as variability in assemblage composition. Clear-cutting homogenised forest environments across all spatial scales, reducing total environmental heterogeneity by 35%. Arthropod beta diversity reflected these changes at larger scales suggesting that environmental heterogeneity is useful in explaining beta diversity both <i>between-cover types</i> and <i>between-stands</i> of the same cover type. However, at smaller scales, <i>within-</i> and <i>between-plots</i> spider beta diversity reflected the lower environmental heterogeneity in regenerating stands, whereas staphylinid and carabids assemblages were not homogenised 12 years post-harvest. Differences in environmental heterogeneity and staphylinid beta diversity between cover types were also important at small scales. In regenerating stands, we detected a subtle yet notable effect of pre-felling cover type on environmental heterogeneity and arthropods, where pre-felling cover type accounted for a significant amount of variance in beta diversity, indicating that biological legacies (e.g. soil pH reflecting pre-harvest conditions) may have a role in driving beta diversity even 12 years post-harvest. This study highlights the importance of understanding site history when predicting impacts of change in forest ecosystems. Further, to understand drivers of beta diversity we must identify biological legacies shaping community structure.</p></div

An empirical parameterization of subsurface entrainment temperature for improved SST anomaly simulations in an intermediate ocean model

An empirical model for the temperature of subsurface water entrained into the ocean mixed layer (Te) is presented and evaluated to improve sea surface temperature anomaly (SSTA) simulations in an intermediate ocean model (IOM) of the tropical Pacific. An inverse modeling approach is adopted to estimate Te from an SSTA equation using observed SST and simulated upper-ocean currents. A relationship between Te and sea surface height (SSH) anomalies is then obtained by utilizing a singular value decomposition (SVD) of their covariance. This empirical scheme is able to better parameterize Te anomalies than other local schemes and quite realistically depicts interannual variability of Te, including a nonlocal phase lag relation of Te variations relative to SSH anomalies over the central equatorial Pacific. An improved Te parameterization naturally leads to better depiction of the subsurface effect on SST variability by the mean upwelling of subsurface temperature anomalies. As a result, SSTA simulations are significantly improved in the equatorial Pacific; a comparison with other schemes indicates that systematic errors of the simulated SSTAs are significantly small—apparently due to the optimized empirical Teparameterization. Cross validation and comparisons with other model simulations are made to illustrate the robustness and effectiveness of the scheme. In particular it is demonstrated that the empirical Te model constructed from one historical period can be successfully used to improve SSTA simulations in another

Wing-dimorphism and population expansion of Pterostichus melanarius (Illiger, 1798) at small and large scales in central Alberta, Canada (Coleoptera, Carabidae, Pterostichini)

A study spanning ten years revealed changes in wing-morph ratios corroborating the hypothesis that the wing-dimorphic introduced carabid, Pterostichus melanarius Ill., is spreading through flight, from the city of Edmonton, Canada and establishing populations in natural aspen forest of more rural areas 45-50 km to the East. Comparison of wing-morph ratios between P. melanarius and the native wing dimorphic species Agonum retractum LeConte suggests that the spatial variation in ratios for P. melanarius does not reflect underlying environmental variation, but instead the action of selective forces on this wing-dimorphic species. About ten years after its earliest detection in some rural sites the frequency of macropterous individuals in P. melanarius has decreased c. five-fold, but it is still above the level seen in European populations in which the two wing-morphs are thought to exist in equilibrium. P. melanarius is expanding its range in native aspen forest much faster than three other introduced species Clivina fossor L.), Carabus granulatus O.F. Müller and Clivina fossor L also encountered in this study. The two Carabus species are flightless, but C. fossor can be dimorphic. Although these four non-native ground beetle species comprise >85% of the carabids collected at sites in urban Edmonton, activity-density of native carabids was similar across the urban-rural gradient, suggesting little direct impact of introduced species on the local abundance of native species. In a second study conducted at a smaller scale near George Lake, Alberta, macropterous individuals of P. melanarius have penetrated furthest and most rapidly into native aspen forest. Furthermore, the percentage of micropterous individuals has increased markedly in areas first colonized a decade previously. Overall, these studies support the idea that macropterous beetles in wing-d dimorphic species are important vanguards for early colonization of unexploited territory, but that flightless individuals replace the flying morph relatively rapidly once populations are established