HYDRINDIC - Suivi et évaluation de la restauration/création de zones humides avec un indicateur hydrologique, Guide méthodologique

National audienceEn France, afin de pallier la dégradation et destruction des zones humides, de nombreux projets de restauration/création de zones humides voient le jour. Une partie de ces opérations sont réalisées dans le contexte réglementaire de la compensation écologique. Ces opérations sont désormais soumises à obligation de résultat et doivent, pour démontrer leur efficacité, disposer d’indicateurs robustes et facilement mobilisables. D’une façon plus générale, disposer d’indicateurs de suivi permet d’évaluer l’efficacité des opérations de restauration/création de zones humides et d’améliorer progressivement les pratiques.Malgré le développement de méthodes et d’indicateurs pour le suivi des zones humides (MhéO, RhoMeO…), l’utilisation de piézomètres simples (tubes de moins de 2 m) pour connaitre la profondeur et les fluctuations de la nappe d'eau superficielle restent peu fréquents. Ils sont pourtant particulièrement utiles en amont des opérations de restauration, afin de dimensionner le projet, et lors des suivis après travaux pour identifier les éventuelles causes d’échec du projet et y remédier. En effet, le maintien d’un bon fonctionnement hydrologique détermine l’avenir d’une zone humide sur le long terme. L’absence d’information sur le fonctionnement hydrologique d’une zone pressentie pour des travaux de restauration/création est un frein important à la réussite des projets. Ce guide méthodologique a été construit pour lever les freins actuels à la mise en place de piézomètres et compléter les indicateurs existants par un indicateur hydrologique (HYDRINDIC). Cet indicateur repose sur la comparaison annuelle de chroniques piézométriques entre une zone humide en voie de restauration/création et des zones humides correspondant à l'objectif de restauration/création (SCORs). Les données piézométriques récoltées sur les SCORs permettent de construire une enveloppe de référence, c’est-à-dire une gamme de variations de profondeur de nappe « autorisée » pour objectiver une conclusion sur le succès vraisemblable de la restauration/création d’un point de vue hydrologique.Le guide méthodologique aborde notamment la définition des sites suivis, la stratégie de déploiement des piézomètres, le matériel nécessaires, les coûts, la méthode d’analyse et d’interprétation, etc. et s’adresse à un public technique non spécialisé en hydrologie et statistique. Il est accompagné de deux outils téléchargeables gratuitement en ligne, permettant la visualisation des données, le calcul de l’indicateur et l’interprétation des résultats. Le guide et l’indicateur proposé ont vocation à être mis à jour régulièrement, en fonction de l’avancée des connaissance et des retours d’expérience

HYDRINDIC : suivre et évaluer l’efficacité des opérations de restauration/création de zones humides avec un indicateur hydrologique

National audienceA large number of wetland restoration/creation operations are emerging in France. The efficiency of these operations must be evaluated in the short, medium and long term. It is also the case of compensation operations which, in order to demonstrate the efficiency of their restoration/creation operations, must have robust and easily mobilisable indicators. The HYDRINDIC indicator was thus developed to assess the efficiency of wetland restoration/creation operations from a hydrological point of view.that are now under an obligation to achieve results and must, in order to demonstrate the efficiency of their restoration/creation operations, have robust and easily mobilisable indicators. The HYDRINDIC indicator was thus developed to assess the efficiency of wetland restoration/creation operations from a hydrological point of view.Un grand nombre d’opérations de restauration/création de zones humides voient le jour en France. L’efficacité de ces dernières doit être évaluée à court, moyen et long terme. C’est d’ailleurs le cas des opérations de compensation qui sont désormais soumises à obligation de résultat et doivent, pour démontrer l’efficacité de leurs opérations de restauration/création, disposer d’indicateurs robustes et facilement mobilisables. L’indicateur HYDRINDIC a ainsi été construit pour permettre le suivi et l’évaluation de l’efficacité des opérations de restauration/création de zones humides d’un point de vue hydrologique

On the Use of Hydrological Models and Satellite Data to Study the Water Budget of River Basins Affected by Human Activities: Examples from the Garonne Basin of France

Natural and anthropogenic forcing factors and their changes significantly impact water resources in many river basins around the world. Information on such changes can be derived from fine scale in situ and satellite observations, used in combination with hydrological models. The latter need to account for hydrological changes caused by human activities to correctly estimate the actual water resource. In this study, we consider the catchment area of the Garonne river (in France) to investigate the capabilities of space-based observations and up-to-date hydrological modeling in estimating water resources of a river basin modified by human activities and a changing climate. Using the ISBA-MODCOU and SWAT hydrological models, we find that the water resources of the Garonne basin display a negative climate trend since 1960. The snow component of the two models is validated using the moderate-resolution imaging spectroradiometer snow cover extent climatology. Crop sowing dates based on remote sensing studies are also considered in the validation procedure. Use of this dataset improves the simulated evapotranspiration and river discharge amounts when compared to conventional data. Finally, we investigate the benefit of using the MAELIA multi-agent model that accounts for a realistic agricultural and management scenario. Among other results, we find that changes in crop systems have significant impacts on water uptake for agriculture. This work constitutes a basis for the construction of a future modeling framework of the sociological and hydrological system of the Garonne river region

Intracranial pressure monitoring with and without brain tissue oxygen pressure monitoring for severe traumatic brain injury in France (OXY-TC): an open-label, randomised controlled superiority trial

International audienceBackground: Optimisation of brain oxygenation might improve neurological outcome after traumatic brain injury. The OXY-TC trial explored the superiority of a strategy combining intracranial pressure and brain tissue oxygen pressure (PbtO2) monitoring over a strategy of intracranial pressure monitoring only to reduce the proportion of patients with poor neurological outcome at 6 months.Methods: We did an open-label, randomised controlled superiority trial at 25 French tertiary referral centres. Within 16 h of brain injury, patients with severe traumatic brain injury (aged 18-75 years) were randomly assigned via a website to be managed during the first 5 days of admission to the intensive care unit either by intracranial pressure monitoring only or by both intracranial pressure and PbtO2 monitoring. Randomisation was stratified by age and centre. The study was open label due to the visibility of the intervention, but the statisticians and outcome assessors were masked to group allocation. The therapeutic objectives were to maintain intracranial pressure of 20 mm Hg or lower, and to keep PbtO2 (for those in the dual-monitoring group) above 20 mm Hg, at all times. The primary outcome was the proportion of patients with an extended Glasgow Outcome Scale (GOSE) score of 1-4 (death to upper severe disability) at 6 months after injury. The primary analysis was reported in the modified intention-to-treat population, which comprised all randomly assigned patients except those who withdrew consent or had protocol violations. This trial is registered with ClinicalTrials.gov, NCT02754063, and is completed.Findings: Between June 15, 2016, and April 17, 2021, 318 patients were randomly assigned to receive either intracranial pressure monitoring only (n=160) or both intracranial pressure and PbtO2 monitoring (n=158). 27 individuals with protocol violations were not included in the modified intention-to-treat analysis. Thus, the primary outcome was analysed for 144 patients in the intracranial pressure only group and 147 patients in the intracranial pressure and PbtO2 group. Compared with intracranial pressure monitoring only, intracranial pressure and PbtO2 monitoring did not reduce the proportion of patients with GOSE score 1-4 (51% [95% CI 43-60] in the intracranial pressure monitoring only group vs 52% [43-60] in the intracranial pressure and PbtO2 monitoring group; odds ratio 1·0 [95% CI 0·6-1·7]; p=0·95). Two (1%) of 144 participants in the intracranial pressure only group and 12 (8%) of 147 participants in the intracranial pressure and PbtO2 group had catheter dysfunction (p=0.011). Six patients (4%) in the intracranial pressure and PbtO2 group had an intracrebral haematoma related to the catheter, compared with none in the intracranial pressure only group (p=0.030). No significant difference in deaths was found between the two groups at 12 months after injury. At 12 months, 33 deaths had occurred in the intracranial pressure group: 25 (76%) were attributable to the brain trauma, six (18%) were end-of-life decisions, and two (6%) due to sepsis. 34 deaths had occured in the intracranial pressure and PbtO2 group at 12 months: 25 (74%) were attributable to the brain trauma, six (18%) were end-of-life decisions, one (3%) due to pulmonary embolism, one (3%) due to haemorrhagic shock, and one (3%) due to cardiac arrest.Interpretation: After severe non-penetrating traumatic brain injury, intracranial pressure and PbtO2 monitoring did not reduce the proportion of patients with poor neurological outcome at 6 months. Technical failures related to intracerebral catheter and intracerebral haematoma were more frequent in the intracranial pressure and PbtO2 group. Further research is needed to assess whether a targeted approach to multimodal brain monitoring could be useful in subgroups of patients with severe traumatic brain injury-eg, those with high intracranial pressure on admission

Outcomes After Endovascular Therapy With Procedural Sedation vs General Anesthesia in Patients With Acute Ischemic Stroke The AMETIS Randomized Clinical Trial

International audienceImportance General anesthesia and procedural sedation are common practice for mechanical thrombectomy in acute ischemic stroke. However, risks and benefits of each strategy are unclear. Objective To determine whether general anesthesia or procedural sedation for anterior circulation large-vessel occlusion acute ischemic stroke thrombectomy are associated with a difference in periprocedural complications and 3-month functional outcome. Design, Setting, and Participants This open-label, blinded end point randomized clinical trial was conducted between August 2017 and February 2020, with final follow-up in May 2020, at 10 centers in France. Adults with occlusion of the intracranial internal carotid artery and/or the proximal middle cerebral artery treated with thrombectomy were enrolled. Interventions Patients were assigned to receive general anesthesia with tracheal intubation (n = 135) or procedural sedation (n = 138). Main Outcomes and Measures The prespecified primary composite outcome was functional independence (a score of 0 to 2 on the modified Rankin Scale, which ranges from 0 [no neurologic disability] to 6 [death]) at 90 days and absence of major periprocedural complications (procedure-related serious adverse events, pneumonia, myocardial infarction, cardiogenic acute pulmonary edema, or malignant stroke) at 7 days. Results Among 273 patients evaluable for the primary outcome in the modified intention-to-treat population, 142 (52.0%) were women, and the mean (SD) age was 71.6 (13.8) years. The primary outcome occurred in 38 of 135 patients (28.2%) assigned to general anesthesia and in 50 of 138 patients (36.2%) assigned to procedural sedation (absolute difference, 8.1 percentage points; 95% CI, −2.3 to 19.1; P = .15). At 90 days, the rate of patients achieving functional independence was 33.3% (45 of 135) with general anesthesia and 39.1% (54 of 138) with procedural sedation (relative risk, 1.18; 95% CI, 0.86-1.61; P = .32). The rate of patients without major periprocedural complications at 7 days was 65.9% (89 of 135) with general anesthesia and 67.4% (93 of 138) with procedural sedation (relative risk, 1.02; 95% CI, 0.86-1.21; P = .80). Conclusions and Relevance In patients treated with mechanical thrombectomy for anterior circulation acute ischemic stroke, general anesthesia and procedural sedation were associated with similar rates of functional independence and major periprocedural complications. Trial Registration ClinicalTrials.gov Identifier: NCT0322914