Maximal care considerations when treating patients with end-stage heart failure: ethical and procedural quandaries in management of the very sick

Deciding who should receive maximal technological treatment options and who should not represents an ethical, moral, psychological and medico-legal challenge for health care providers. Especially in patients with chronic heart failure, the ethical and medico-legal issues associated with providing maximal possible care or withholding the same are coming to the forefront. Procedures, such as cardiac transplantation, have strict criteria for adequate candidacy. These criteria for subsequent listing are based on clinical outcome data but also reflect the reality of organ shortage. Lack of compliance and non-adherence to lifestyle changes represent relative contraindications to heart transplant candidacy. Mechanical circulatory support therapy using ventricular assist devices is becoming a more prominent therapeutic option for patients with end-stage heart failure who are not candidates for transplantation, which also requires strict criteria to enable beneficial outcome for the patient. Physicians need to critically reflect that in many cases, the patient’s best interest might not always mean pursuing maximal technological options available. This article reflects on the multitude of critical issues that health care providers have to face while caring for patients with end-stage heart failure

Global patterns in monthly activity of influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus: a systematic analysis

Background Influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus are the most common viruses associated with acute lower respiratory infections in young children (= 65 years). A global report of the monthly activity of these viruses is needed to inform public health strategies and programmes for their control.Methods In this systematic analysis, we compiled data from a systematic literature review of studies published between Jan 1, 2000, and Dec 31, 2017; online datasets; and unpublished research data. Studies were eligible for inclusion if they reported laboratory-confirmed incidence data of human infection of influenza virus, respiratory syncytial virus, parainfluenza virus, or metapneumovirus, or a combination of these, for at least 12 consecutive months (or 52 weeks equivalent); stable testing practice throughout all years reported; virus results among residents in well-defined geographical locations; and aggregated virus results at least on a monthly basis. Data were extracted through a three-stage process, from which we calculated monthly annual average percentage (AAP) as the relative strength of virus activity. We defined duration of epidemics as the minimum number of months to account for 75% of annual positive samples, with each component month defined as an epidemic month. Furthermore, we modelled monthly AAP of influenza virus and respiratory syncytial virus using site-specific temperature and relative humidity for the prediction of local average epidemic months. We also predicted global epidemic months of influenza virus and respiratory syncytial virus on a 5 degrees by 5 degrees grid. The systematic review in this study is registered with PROSPERO, number CRD42018091628.Findings We initally identified 37 335 eligible studies. Of 21 065 studies remaining after exclusion of duplicates, 1081 full-text articles were assessed for eligibility, of which 185 were identified as eligible. We included 246 sites for influenza virus, 183 sites for respiratory syncytial virus, 83 sites for parainfluenza virus, and 65 sites for metapneumovirus. Influenza virus had clear seasonal epidemics in winter months in most temperate sites but timing of epidemics was more variable and less seasonal with decreasing distance from the equator. Unlike influenza virus, respiratory syncytial virus had clear seasonal epidemics in both temperate and tropical regions, starting in late summer months in the tropics of each hemisphere, reaching most temperate sites in winter months. In most temperate sites, influenza virus epidemics occurred later than respiratory syncytial virus (by 0.3 months [95% CI -0.3 to 0.9]) while no clear temporal order was observed in the tropics. Parainfluenza virus epidemics were found mostly in spring and early summer months in each hemisphere. Metapneumovirus epidemics occurred in late winter and spring in most temperate sites but the timing of epidemics was more diverse in the tropics. Influenza virus epidemics had shorter duration (3.8 months [3.6 to 4.0]) in temperate sites and longer duration (5.2 months [4.9 to 5.5]) in the tropics. Duration of epidemics was similar across all sites for respiratory syncytial virus (4.6 months [4.3 to 4.8]), as it was for metapneumovirus (4.8 months [4.4 to 5.1]). By comparison, parainfluenza virus had longer duration of epidemics (6.3 months [6.0 to 6.7]). Our model had good predictability in the average epidemic months of influenza virus in temperate regions and respiratory syncytial virus in both temperate and tropical regions. Through leave-one-out cross validation, the overall prediction error in the onset of epidemics was within 1 month (influenza virus -0.2 months [-0.6 to 0.1]; respiratory syncytial virus 0.1 months [-0.2 to 0.4]).Interpretation This study is the first to provide global representations of month-by-month activity of influenza virus, respiratory syncytial virus, parainfluenza virus, and metapneumovirus. Our model is helpful in predicting the local onset month of influenza virus and respiratory syncytial virus epidemics. The seasonality information has important implications for health services planning, the timing of respiratory syncytial virus passive prophylaxis, and the strategy of influenza virus and future respiratory syncytial virus vaccination. Copyright (C) 2019 The Author(s). Published by Elsevier Ltd

Modular Interpreters For The Masses: Implicit Context Propagation Using Object Algebras

International audienceModular interpreters have the potential to achieve component-based language development: instead of writing language interpreters from scratch, they can be assembled from reusable, semantic building blocks. Unfortunately, traditional language interpreters are hard to extend because different language constructs may require different interpreter signatures. For instance, arithmetic interpreters produce a value without any context information, whereas binding constructs require an additional environment. In this paper, we present a practical solution to this problem based on implicit context propagation. By structuring denotational-style interpreters as Object Algebras, base interpreters can be retroactively lifted into new interpreters that have an extended signature. The additional parameters are implicitly propagated behind the scenes, through the evaluation of the base interpreter. Interpreter lifting enables a flexible style of component-based language development. The technique works in mainstream object-oriented languages, does not sacrifice type safety or separate compilation, and can be easily automated. We illustrate implicit context propagation using a modular definition of Featherweight Java and its extension to support side-effects