L’effet de l’extubation precoce apres chirurgie cardiaque pour la rehabilitation post opératoire

Introduction: La réhabilitation post opératoire en chirurgie cardiaque est basée sur une prise en charge médico-chirurgicale visant à diminuer la durée de séjour hospitalier et les coûts de soins de cette chirurgie à haut risque. L’extubation trachéale précoce, définie par une extubation avant la sixième heure, constitue la pierre angulaire du Fast-tracking. L’objectif de notre étude est d’évaluer dans notre institution la pratique du fasttrack et notamment de l’extubation trachéale précoce en chirurgie cardiaque adulte programmée. Méthodes: Nous avons conduit une étude descriptive incluant tous les patients âgés de plus 18 ans opérés consécutivement d’une chirurgie cardiaque programmée et qui ont été pris en charge en post-opératoire dans l’unité de réanimation post-opératoire du Service de chirurgie thoracique et cardiovasculaire du CHU HABIB BOURGUIBA de SFAX. Les critères d’inclusion des malades: âgés de 18 ans et plus, opérés d’une chirurgie cardiaque programmée, dont la prise en charge post-opératoire s’est faite dans l’unité de réanimation post-opératoire du service de chirurgie cardio-vasculaire et thoracique. Notre protocole d’anesthésie a été standardisé pour tous les patients: Propofol, Rémifentanil, Cisatracrium. Nous avons noté le délai d’extubation en post opératoire et les facteurs qui allongent ce délai d’extubation. Résultats: Nous avons colligé 200 observations de malades consécutifs qui ont bénéficié d’une chirurgie cardiaque programmée. Parmi ces malades 115 étaient opérés pour pontage aorto-coronaire, 79 pour chirurgie valvulaire et 6 pour chirurgie combinée ou autre. Les caractéristiques démographiques sont comparables. En post-opératoire, nous avons pu extuber 152 soit 76% de nos malades avant la sixième heure. Quarante-huit patients n’ont pas pu être extubés avant la sixième heure. Les principales causes de l’échec de l’extubation précoce sont : fortes doses de catécholamines, saignement, arythmie et les troubles neurologiques. Conclusion: Nous avons pu démontrer que la réalisation de la réhabilitation post opératoire était possible dans notre institution et tous les patients bénéficiant d’une chirurgie cardiaque réglée devraient être candidats à l’extubation précoce

A Comprehensive Performance Comparison between Segmental and Conventional Switched Reluctance Machines with Boost and Standard Converters

This paper presents the comparisons between two types of switched reluctance machines (SRMs) and SRM converters. An SRM with a segmental rotor is compared with a conventional SRM (CSRM), and an SRM converter containing a passive boost circuit is compared with a conventional asymmetric half-bridge (AHB) converter. The segmental SRM has an asymmetric rotor with a segmented structure. The four rotor segments are made of steel laminations. Two segments are misaligned with the other two by 15 degrees. The torque ripple of the SRM with this structure is decreased, and the static torque is increased compared to a conventional SRM. The boost converter comprises a front-end circuit and a conventional AHB converter. The front-end circuit boosts the voltage level. The boosted voltage accelerates the rising and falling progress of the phase current. In this way, the SRM can obtain a greater speed and a smaller torque ripple. The comparison is conducted in simulation and validated through the experimental results. The experiment results have demonstrated that the segmental SRM obtains a maximum 7% torque ripple reduction at a low-speed range, compared to the CSRM. With the boost converter, both the CSRM and the segmental SRM can achieve a lower torque ripple and a higher maximum speed

Multiphase Motors and Drive Systems for Electric Vehicle Powertrains: State of the Art Analysis and Future Trends

Multiphase drives (MPDs) have been the subject of research for the last two decades. Despite being a technology that is still in the process of development, a significant number of research studies and developments have been reported in scientific literature over the past few years. This article aims to collect and present a review of these recent contributions, providing a comprehensive and insightful state of the art on this topic and future technology trends. The elaborated aspects include the advantages of multiphase machines, a general introduction to five-phase and six-phase machines, and their modelling techniques. In addition, new promising MPD topologies are covered. Recent advances in modulation techniques and the control of multilevel converters are also discussed. Finally, future trends and challenges in further developing this technology are discussed

Design Optimization of a Switched Reluctance Machine with an Improved Segmental Rotor for Electric Vehicle Applications

In this article, a switched reluctance machine (SRM) with six phases and a misaligned segmental rotor is proposed. The segmental rotor has an internal 15-degree misalignment, allowing the SRM structure to be a one-layer 2D structure with a short flux path structure. The proposed SRM produces a relatively low torque ripple by exciting two phases simultaneously. Additionally, an optimization method is applied, allowing for the maximum torque position of one phase to be aligned with the zero-torque position of the adjacent phase. The finite element method (FEM) is used to analyze and design the proposed SRM and to simulate the proposed liquid cooling system. The static torque waveforms are analyzed, and the dynamic torque waveforms are simulated with a drive using SiC MOSFETs. Finally, a prototype is manufactured, and the experiment is performed to validate the design and simulation results

147: Infective endocarditis in Tunisia: A changing profile?

BackgroundSince the first description of infective endocarditis (IE), the profile of the disease has evolved continuously with stable incidence.ObjectiveTo update information gained on the epidemiology profile of IE in a Tunisian high-volume tertiary care centerPatients and methodsThis was a descriptive retrospective study of patients treated for IE from January 2001 to December 2010. The patients were divided in two groups according to the date of diagnosis of IE: group 1 (from January 2001 to June 2006) and group 2 (from June 2006 to December 2011). These groups were compared for epidemiologic factors and microbiological differences.ResultsA total of 297 patients admitted during the study period met the modified Duke criteria for IE. The comparison of demographic and microbiological characteristics of IE cases over time between the results of the two groups showed that the annual incidence of IE was stable. The sex incidence rates of IE, in particular, incidence among men was relatively stable across the study period and ranged from 60% in 2001-2006 to 58% in 2006-2010, also there was no significant increase in incidence among women (P=ns). Among incident cases, there was a significant increasing age on presentation, with median age increasing from 39.5 years in 2001-2006 to 51.5 years in 2006-2010 (P=0.05). There were no statistically significant decreases in the proportions of cases affecting the aortic valve (P=0.4) and in IE due to oral streptococci (P= ns) over time. Also there was no significant increase in the incidence of Staphylococcus IE. However, the incidence of IE with negative blood culture has remained stable and continues to be high, nearing 50%.The rate of rheumatic heart disease as an underlying heart disease was stable over time. However, the standardized incidence of IE has increased in patients with prosthetic valves (P= ns). Overall in-hospital mortality rate decreased from ((18.6% in 2001-2006 vs 14.6% in 2006-2010.ConclusionThis study has shown that the annual incidence of IE is stable in Tunisia. However, profound changes in the epidemiological profile of this disease have not been noted in our population