Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Social evolution in structured populations

<p>(50-minute) Talk given in Lausanne in May 2014, on my work on Social Evolution in Structured populations.</p> <p> </p> <p>Related paper:</p> <p>http://www.nature.com/ncomms/2014/140306/ncomms4409/full/ncomms4409.html</p> <p> </p> <p>(email me for a reprint)</p

Multidimensional (co)evolutionary stability

<p>20-minute talk given in the MBE15 conference in Leicester (April 2015), based on the paper</p> <p>Multidimensional (Co)Evolutionary Stability.<br>F. Débarre, S. L. Nuismer, and M. Doebeli<br>The American Naturalist<br>Vol. 184, No. 2 (August 2014) , pp. 158-171<br>Stable URL: http://www.jstor.org/stable/10.1086/677137</p> <p> </p> <p>3-minute version available there</p> <p>http://figshare.com/articles/Multidimensional_co_evolutionary_stability/1057997</p> <p> </p

Minimum branching population size

<p>Talk on the limits to evolutionary divesification in populations of finite size. Given on 15 Jun 2014 at the ECMTB 2014 meeting in Gothenburg, Sweden, during the mini symposium "Unifying Evolutionary Theory: Connecting Adaptive Dynamics, Population Genetics & Quantitative Genetics" organized by Helene Weigang.</p

Evolutionary epidemiology of drug resistance, a spatial model

<p>Presentation given at the R0 workshop in Paris, in October 2008. </p> <p>The corresponding paper was published in 2009:</p> <p>DOI: 10.1371/journal.pcbi.1000337</p> <p><br> </p

Living, competing and evolving in a heterogeneous environment

Tout observateur peut constater la diversité des milieux sur Terre. La compréhension des liens entre cette diversité des habitats et la biodiversité est l'un des thèmes centraux en Écologie, en Évolution et en Biologie de la conservation. Je m'intéresse dans cette thèse aux conséquences écologiques (à court terme) et évolutives (à plus long terme) de la structuration spatiale et de l'hétérogénéité de l'environnement. Je développe et analyse plusieurs modèles mathématiques, combinant différents formalismes théoriques (dynamiques adaptatives, génétique des populations, génétique quantitative). Ces modèles permettent d'explorer les conséquences de l'hétérogénéité spatiale de l'environnement sur (1) les conditions de persistance des populations ; (2) la coexistence entre différents phénotypes et (3) la dynamique évolutive des populations. Je montre ainsi l'importance (i) de l'intensité et de la place de la migration dans le cycle de vie ; (ii) du type de structure spatiale (explicite ou implicite, continu ou discret) ; (iii) de la forme du compromis évolutif, et donc des coûts d'adaptation à une autre ressource ; et enfin (iv) des éventuels rétrocontrôles démographiques. J'illustre à l'aide des interactions entre hôtes et parasites l'importance des hétérogénéités spatiales. Un premier exemple concerne leur utilisation dans la gestion des pharmacorésistances ou des résistances aux insecticides : une répartition hétérogène du traitement permet d'éviter la propagation de parasites ou de nuisibles résistants. Un second exemple, enfin, illustre comment les hétérogénéités dues à l'auto-structuration spatiale influencent l'évolution de stratégies de défense des hôtes, et permettent l'évolution de défenses altruistes.Any observer can notice the diversity of habitats on Earth. Understanding the links betweenthis diversity of habitats and biodiversity is a core topic in Ecology, Evolution andConservation Biology.In this thesis, I study the ecological (short-term) and evolutionary (long-term) consequencesof spatial structuring and environmental heterogeneities. I develop and analyzeseveral mathematical models, which combine different theoretical frameworks (adaptivedynamics, population genetics, and quantitative genetics). I explore the consequences ofspatial heterogeneities on (1) the conditions for population persistence; (2) the coexistenceof different phenotypes, and (3) evolutionary dynamics of populations. I show that theresults depend on (i) the life-cycle, and in particular whether migration influences local regulation;(ii) the choice of the spatial structure (explicit or implicit, continuous or discrete);(iii) the shape of the trade-off, and hence the costs of adaptation to another resource, andfinally (iv) the potential demographical feedbacks.I use the specific case of hosts and parasites interactions to illustrate the importanceof spatial heterogeneities. As a first example, I show that a heterogeneous application oftreatments can help prevent the spread of resistant parasites or pests. Secondly, I show howspatial heterogeneities due to self-structuring influence the evolution of host defense strategies,and allow for the evolution of altruistic defense strategies.MONTPELLIER-BU Sciences (341722106) / SudocSudocFranceF

Spatial structure and the evolution of altruistic host defense strategies

<p>(email me for a reprint)</p

Massol-Debarre_Scripts_20150416

<p>Scripts to run the simulations and plot the figures of our manuscript on the effect of life cycles on the evolution of dispersal</p

R scripts for ms "Fitness costs in spatially structured environments"

<p>R scripts to rerun the simulations and plot the figures of manuscript on "Fitness costs in spatially structured environments".</p

Evolution of specialist vs generalist strategies in a continuous environment

<p>Talk given at the 2009 ESEB meeting in Torino, Italy.</p> <p>Corresponding paper published in 2010 in Journal of Evolutionary Biology, </p> <p>http://onlinelibrary.wiley.com/doi/10.1111/j.1420-9101.2010.01966.x/pdf</p