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Given that pandemic swine flu outbreak led to substantial admission in intensive care unit, extracorporeal membrane oxygenation has been increasingly applied to those who suffered from H1N1 infection induced acute respiratory distress syndrome. This review is going to evaluate the effectiveness of using ECMO based on five related observational studies. The result, discussion and policy implication in Hong Kong are discussed. Since the ECMO system has been technological improved in recent years, there are less complications when applying ECMO. In view of evidence of reviewed studies, application of ECMO in Hong Kong can be considered as cost effective. And since only a few hospitals in Hong Kong can offer ECMO application, retrieval teams are needed to ensure safety transfer between hospitals. / published_or_final_version / Public Health / Master / Master of Public Health

Over 26 million Americans suffer from pulmonary disease, resulting in more than 150,000 deaths annually. Lung transplantation remains the only definitive treatment for many patients, but has meager survival rates and only approximately 1,700 of the 2,200 patients added to the lung transplant wait list each year are transplanted. Extracorporeal gas exchangers have been used as an alternative to mechanical ventilation in acute respiratory failure and as a bridge to transplantation in chronic respiratory failure. Current gas exchangers are limited by their high resistance and low biocompatibility that lead to patient complications and device clot formation. Therefore, there exists a dire need for improved devices that can act as destination therapy. To accomplish the goal of destination therapy, this dissertation discusses three studies that were performed to pave the way. First, I examined clot formation and failure patterns of two common clinical devices (Maquet’s CardioHelp (CH) and Quadrox (Qx)) to further our understanding of their limitations with respect to long-term support. Overall, it was demonstrated that the Qx devices fail earlier and more frequently than CH devices and result in a significantly greater reduction in platelet count, and that a four-inlet approach is beneficial. Next, I determined the optimal sweep gas nitric oxide (NO) concentration that minimizes platelet binding and activation while ensuring that blood methemoglobin (metHb) concentrations increase less than 5%. Miniature artificial lungs were attached to rabbits in a pumped veno-venous configuration and run for 4 h with NO added to the sweep gases in concentrations of 0, 100, 250, and 500 ppm (n=8 ea.). 100 ppm significantly reduced the amount of platelet consumption (p < 0.05), reduced platelet activation as measured by soluble p-selectin (p < 0.05), and had negligible increases in metHb and will thus be used in future experiments. Last, I tested the Pulmonary Assist Device (PAD) which was designed for long term use as a bridge to transplantation and destination therapy. Benchtop experiments were performed that confirmed that it meets our design and performance goals. From here, we are equipped to commence with 30-day PAD testing in sheep.

京都大学 / 0048 / 新制・課程博士 / 博士(社会健康医学) / 甲第22649号 / 社医博第109号 / 新制||社医||11(附属図書館) / 京都大学大学院医学研究科社会健康医学系専攻 / (主査)教授 中山 健夫, 教授 川上 浩司, 教授 伊達 洋至 / 学位規則第4条第1項該当 / Doctor of Public Health / Kyoto University / DFAM

Extracorporeal Membrane Oxygenation (ECMO) is a life-saving therapy usedfor support in critical heart and/or lung failure. Patient’s blood is pumped viaan artificial lung for oxygenation outside of the body. The circuit is composedof a blood pump, cannulae for drainage and reinfusion, a membrane lung,tubing and connectors. Its use is associated with thromboembolic complicationsand hemolytic damage. Detailed numerical studies of two blood pumps anda lighthouse tip drainage cannula were undertaken to characterize the flowstructures in different scenarios and their link to platelet activation. The pumpsimulations were modelled according to manufacturer’s proclaimed use but alsoin off-design conditions with flow rates used in adult and neonatal patients.Lagrangian Particle Tracking (LPT) was used to simulate the injection ofparticles similar in size to platelets to compute platelet activation state (PAS).The results indicated that low flow rates impacted PAS similarly to high flowrates due to increased residence time leading to prolonged exposure to shearstress despite the fact that shear per se was lower at low flow rate. Regardingthe cannula, the results showed that a flow pattern similar to a jet in crossflowdeveloped at the side holes. A parameter study was conducted to quantifydrainage characteristics in terms of flow rate distribution across the holes wheninput variables of flow rate, modelled fluid, and hematocrit were altered. Thefindings showed, across all the cases, that the most proximal hole row drainedthe largest fraction of fluid. The effects due to the non-Newtonian nature ofblood were confined to regions far from the cannula holes and the flow structuresshowed very limited dependence on the hematocrit. A scaling law was found tobridge the global drainage performance of fluid between water and blood. / <p>QC 210906</p>

Extracorporeal membrane oxygenation (ECMO) is a method that allows extracorporeal life support in potentially reversible life-threatening conditions affecting the heart or lungs which are refractory to conventional treatment. Depending on the parameters of its setting, this method affects the haemodynamics of the cardiovascular system and the perfusion of the target organ. From the point of view of its character, the necessity for invasive application, and the function thereof in the conditions of the cardiovascular system, ECMO is regarded as a risky method accompanied by a number of complications. Among the critical complications are thromboembolic complications affecting the central nervous system (CNS) and haemorrhagic complications. The goal of this paper is to present and verify the prerequisites for the formation of periprocedural embolisms affecting the CNS and to evaluate the regional haemodynamics of the CNS. This is done by analysing the presence of embolisms and by analysing the parameters of blood flow rates in the right common carotid artery (arteria carotis communis-ACC) and the corresponding oxygenation of the brain tissue during various flow rate parameters generated by the ECMO support on induced heart failure in a biological porcine model. In the first section of the paper, 8...

L’insuffisance cardiaque aigue est une émergence médicale qui nécessite une prise en charge multidisciplinaire. L’Extracorporeal Life Support (ECLS) peut être envisagé comme option thérapeutique pour les formes d’insuffisance cardiaque aigue réfractaire au traitement conventionnel. L’objectif de ce projet de recherche clinique est de fournir une vue d’ensemble de l’ECLS dans la prise en charge du choc cardiogénique et de l’arrêt cardiaque réfractaire. L’intoxication médicamenteuse et la myocardite sont les meilleures indications à l’implantation de l’ECLS en considération de leur potentiel de récupération myocardique très élevé. La défaillance primaire du greffon après transplantation cardiaque et l’infarctus du myocarde présentent des résultats plus mitigés avec l’ECLS en raison d’une physiopathologie plus complexe. Le choc cardiogénique postcardiotomie après une intervention de chirurgie cardiaque montre des résultats décevants en raison du profile préopératoire des patients. L’arrêt cardiaque aussi exige une prise en charge immédiate et l’ECLS peut être considéré comme une solution thérapeutique de sauvetage. Une meilleure sélection des patients s’impose afin d’améliorer les résultats de l’ECLS pour l’arrêt cardiaque réfractaire intrahospitalier. Les résultats de l’ECLS pour l’arrêt cardiaque réfractaire extrahospitalier sont dictés principalement par le temps de réanimation cardio-pulmonaire et le rythme cardiaque. Les rythmes non choquables pourraient être considérés comme une contre-indication formelle à l’utilisation de l’ECLS autorisant une concentration de nos efforts sur les rythmes choquables où les chances de survie sont plus importantes / Acute heart failure is a clinical situation requiring a prompt multidisciplinary approach. Extracorporeal Life Support (ECLS) could represent a therapeutic option for acute heart failure refractory to standard maximal treatment. The aim of this report is to offer an overview of ECLS in the management of refractory cardiogenic shock and cardiac arrest. Drug intoxication and myocarditis are the best indications of ECLS in consideration of their high potential of myocardial recovery. Primary graft dysfunction after heart transplantation and acute myocardial infarction show reduced survival rates owing to their more complex pathophysiology. Postcardiotomy cardiogenic shock after cardiac surgery operations displays poor outcomes due to the preoperative profile of the patients. ECLS could be also considered as a rescue solution for refractory cardiac arrest. A better selection of in-hospital cardiac arrest patients is mandatory to improve ECLS outcomes. In-hospital cardiac arrest patients with a reversible cause like drug intoxication and acute coronary syndrome should benefit from ECLS whereas end-stage cardiomyopathy and postcardiotomy patients with an unclear cause of cardiac arrest should be contraindicated to avoid futile support. ECLS for refractory out-ofhospital cardiac arrest should be limited in consideration of its poor, especially neurological, outcome and the results are mainly limited by the low-flow duration and cardiac rhythm. Nonshockable rhythms could be considered as a formal contraindication to ECLS for refractory out-of-hospital cardiac arrest allowing a concentration of our efforts on the shockable rhythms, where the chances of success are substantial

Introduction : L’arrêt cardiaque réfractaire est défini par l’absence du retour à l’activité circulatoire spontané (RACS) après 30 minutes de réanimation cardiopulmonaire médicalisé. ExtraCorporeal Membrane Oxygenation (ECMO) représente une thérapie alternative urgente dans cette population. L’hémodynamique post la réanimation cardiopulmonaire extracorporel (E-CRP) est un entité complexe et le pris en charge dans les premières heures suivant l’implantation d’ECMO n’est pas bien décrit. L’objectif de cette étude est d’évaluer l’effet de deux stratégie de débit d’ECMO dans un modèle porcin d’arrêt cardiaque réfractaire sur les conséquences métaboliques, microcirculatoires et inflammatoires.Matériels et Méthodes : l’arrêt cardiaque a été induit par la ligature l’artère intraventriculaire antérieure (IVA) chez 18 cochons. E-RCP a été initié après 40 minutes de low-flow avec un débit d’ECMO bas de 30-35 ml.kg-1.min-1 ou un débit d’ECMO standard de 65-70 ml.kg-1.min-1, avec la même pression artérielle moyenne (PAM) au niveau de 65 mmHg. Les paramètres hémodynamiques et métaboliques ont été évalués avec la clairance de lactate et le débit sanguin carotidien. Les paramètres microcirculatoires ont été évalués par la microcirculation sublinguale avec l’imagerie de SDF et NIRS. Cytokines inflammatoires ont été mesurés avec un plateforme de ELISA multiplexe. Résultats : Pas de différence entre les deux groups à H basale et à l’initiation d’ECMO (H0). La clairance de lactate était plus faible dans le groupe débit bas comparé au groupe débit standard (6.67[-10.43-18.78] vs. 47.41[19.54, 70.69] %, p=0.04). Le débit carotidien était plus bas significativement (p<0.005) dans le groupe débit bas pendant les dernières quatre heures malgré le même niveau de la pression artérielle moyenne. Pour les paramètres microcirculatoires, le flux microcirculatoire sublingual évalué par SDF et le StO2 par NIRS ont été altéré transitoirement à H3 dans le groupe débit bas. Le niveau de cytokine IL-6 était plus élevé significativement dans le groupe débit bas à la fin d’expérimentation. Conclusions : Une réanimation à objectif de débit d’ECMO bas 35 ml.kg-1.min-1 versus standard 70ml.kg-1.min-1dans les six premières heures d’un ACR réfractaire n’est pas associé à une meilleure réversion des conséquences métaboliques, microcirculatoire et inflammatoire avec un objectif de PAM à 65 mmHg dans un modèle porcin / Introduction : Refractory cardiac arrest is defined by the absence of the return of spontaneous circulation (ROCS) within 30 minutes of cardiopulmonary resuscitation (CRP) under medical supervision. ExtraCorporeal membrane oxygenation (ECMO) is an emerging alternative therapy in this population. The post extracorporeal cardiopulmonary resuscitation (ECPR) hemodynamic state is a complex entity and the critical care management in the first hours following ECMO implantation is not well defined. This study was designed to assess the effect of two veno-arterial Extracorporeal Membrane Oxygenation (ECMO) blood-flow strategies in an experimental model of ECPR (extracorporeal cardio-pulmonary resuscitation) on macrocirculatory, metabolic and microcirculatory parameters in the first six hours of ECMO initiation. Material and methods : Cardiac arrest was induced in 18 pigs by surgical ligature of the left descending coronary artery. ECPR was initiated after 40 minutes of low-flow with an ECMO blood-flow of 30-35 ml.kg-1.min-1 (low-blood-flow group, LBF) or 65-70 ml.kg-1.min-1 (standard-blood-flow group, SBF), with the same mean arterial pressure target (65 mmHg). Macrocirculatory and metabolic parameters were assessed by lactate clearance and carotid blood-flow. Microcirculatory parameters were assessed by sublingual microcirculation with Sidestream Dark Field (SDF) imaging and peripheral Near-InfraRed Spectrometry (NIRS). Inflammatory cytokine levels were measured with a multiplexed ELISA-based array platform. Results : There was no between-group difference at baseline and at ECMO initiation (H0). Lactate clearance at H6 was lower in LBF compared to SBF (6.67[-10.43-18.78] vs. 47.41[19.54, 70.69] %, p=0.04). carotid blood flow was significantly lower (p<0.005) during the last four hours despite similar mean arterial pressure levels. For microcirculatory parameters, SDF and NIRS parameters were transitorily impaired at H3 in LBF. IL-6 cytokine level was significantly higher in LBF at the end of the experiment. Conclusion: In an experimental porcine model of refractory cardiac arrest treated by ECMO, a low-blood-flow strategy during the first six hours of resuscitation was associated with lower lactate clearance and lower cerebral blood-flow with no benefits on ischemia-reperfusion parameters

Introduction: Venoarterial extracorporeal membrane oxygenation (VA ECMO) is widely used in the treatment of circulatory failure, but repeatedly, its negative effects on the left ventricle (LV) have been observed. The purpose of this study is to assess the influence of ex- tracorporeal blood flow (EBF) on systemic hemodynamic changes and LV performance parameters during VA ECMO therapy of decompensated heart failure. Methods: Porcine models of low-output chronic and acute heart failure were developed by long-term fast cardiac pacing and coronary hypoxemia, respectively. Profound signs of circulatory decompensation were defined by reduced cardiac output and tissue hypoperfusion. Sub- sequently, under total anesthesia and artificial ventilation, VA ECMO was introduced. LV performance and organ specific parameters were recorded at different levels of EBF using an LV pressure-volume loop analysis, arterial flow probes on carotid and subclavian arteries, and transcutaneous probes positioned to measure cerebral and forelimb regional tissue oxygen saturations. Results: Conditions of severely decompensated heart failure led to systemic hypotension, low tissue and mixed venous oxygen saturations, and increase in LV end-diastolic pressure. By increasing the EBF from minimal flow to 5 L/min, we observed a...