Implante de un dispositivo de asistencia ventricular izquierda definitivo y circulación asistida en cuidados intensivos como terapia puente. Cuidados enfermeros: caso clínico / Permanent left ventricular assistance internal device implantation and assisted circulation in intensive care as bridge therapy. Nursing care: case report

A lo largo de los últimos años la implantación de Dispositivos de Asistencia Ventricular (DAV) está tomando un papel más relevante en el tratamiento de la Insuficiencia Cardíaca (IC). El uso de los DAV también está cambiando hacia la Terapia Definitiva (TD), conformándose como alternativa clara al trasplante cardíaco. La implantación de un DAV, en ocasiones, requiere previamente tratamiento emergente con otros dispositivos de Asistencia Circulatoria Mecánica (ACM) como Circulación Extracorpórea con Membrana de Oxigenación (ECMO) o Asistencia Ventricular paracorpórea Izquierda o Derecha. Por tanto, es necesario el ingreso en Unidades de Cuidados Intensivos (UCI) especializadas en estas terapias hasta la estabilización del paciente y toma de la decisión correcta. Se expone un caso clínico reciente de una persona que requiere asistencia inicial con ECMO V-A emergente en el hospital de origen y su traslado al centro de referencia para posterior asistencia biventricular paracorpórea e implantación definitiva de un DAVI (Dispositivo de Asistencia Ventricular Izquierda). Se exponen la secuencia de decisiones, complicaciones y el plan de cuidados de enfermería inicial en UCI con taxonomía NANDA. Es el primer implante de un DAVI, realizado en nuestro hospital. En él ha intervenido un enorme equipo multidisciplinar.

Over the past few years, the Ventricular Assist Devices (VADs) implementation is taking a relevant role in the Heart Failure (HF) treatment. VADs ́s use is also shifting towards Definitive Therapy (TD), being a clear alternative to heart transplantation. The implantation of a VAD, sometimes, requires a previous emergent treatment with other Mechanical Circulatory Assistance (ACM) devices such as Extracorporeal Circulation with Oxygenation Membrane (ECMO) or Left or Right Paracorporeal Ventricular Assistance. So is necessary of a mobile team for emergency assistance with ECMO and transfer to Intensive Care Units (ICU) which is specialized in these therapies until the patient stabilizes and doctors takes the right decision. A recent clinical case of a patient is exposed. This person required assistance with emergent ECMO V-A (Venous-Arterial) in the hospital of origin and his transfer to the reference center for subsequent biventricular paracorporeal assistance and to the definitive implantation of LVAD (Left Ventricular Assist Device). The sequence of decisions, complications and the initial nursing care plan at ICU with NANDA taxonomy, are presented here. This is the first implant of a LVAD in our hospital. A huge multidisciplinary team has been involved in the project.

Indicações de dispositivos mecânicos de suporte na insuficiência cardíaca refratár / Indications of mechanical support devices in refractory heart failur

A insuficiência cardíaca refratária e o choque cardiogênico estão relacionados aelevadas taxas de mortalidade e a baixa qualidade de vida. As estratégias de tratamento para esses pacientes foram limitadas, nos últimos anos, às terapias farmacológicas que pouco modificaram a evolução da doença. Entretanto, com o desenvolvimento tecnológico em dispositivos mecânicos de suporte circulatório, diversas modalidades terapêuticas utilizando diferentes tipos de tecnologia proporcionam melhor suporte hemodinâmico, diminuição e reversão de disfunções orgânicas causadas pela insuficiência cardíaca.Esses dispositivos quando indicados corretamente melhoram os desfechos clínicos de pacientes que aguardam transplante cardíaco e dos que não são candidatos a transplante. Atualmente, observam-se indicações cada vez mais precoces de dispositivos de suporte circulatório, tornando-os uma terapia essencial no manejo de pacientes cominsuficiência cardíaca refratária ou choque cardiogênico. Esta revisão abordará os principais tipos de dispositivos disponíveis em nosso país e suas indicações...

The refractory heart failure and cardiogenic shock are related to high rates of mortality and poor quality of life. Treatment strategies for these patients have been limited in the last yearsto pharmacological therapies that change only slightly the evolution of the disease. However, with technological advances in mechanical devices for circulatory assistance, various therapeutic modalities using different types of technology provide better hemodynamic support, reduction and reversal of organic dysfunction caused by heart failure. When properly indicated,these devices can provide better clinical outcomes of patients on heart transplantation waiting list and those who are not candidates for transplantation. Contemporarily, indications for mechanical support devices are occurring increasingly earlier, making them an essential therapy in the management of patients with refractory heart failure or cardiogenic shock.This review covers the different types of devices available in our country and its indications...

Analysis of Influence on Single Eythrocyte Injury Caused by Oscillating Boundary Flow Field / 生物医学工程学杂志

The implantable axial blood pump, driven by external electromagnet, is studied recently. It oscillats when it is running because of the elastic implanted environment and driving force disequilibrium, etc. In this paper, a model of single erythrocyte in vibrated flow field was built to simulate the deformation and force of the erythrocyte. By using the mechanical injury principle of blood in blood pump, we studied the injury of a single erythrocyte resulted from oscillating boundary flow field. The research results indicated that the shape of the erythrocyte, force and velocity field nearby, which are affected by oscillating boundary flow field, all cause injury to the erythrocyte. All the researches shown in the present paper are expected to provide theoretical foundation for lightening hemolysis by the blood pump.

Desenvolvimento e estudo In Vitro de um dispositivo de suporte circulatório temporário / Development and in vitro study of a temporary circulatory support device

Um modelo de bomba centrífuga de sangue, denominado dispositivo de suporte circulatório (DSCT), foi desenvolvido para utilização como ponte para decisão e/ou ponte para recuperação. Durante o seu desenvolvimento, foi utilizado a proporção áurea para cálculos das medidas dos componentes. Baseando-se nas condições de uso, foi desenvolvido um modelo DSCT com cone externo, base externa, sistema de mancal e rotor. Como o uso da espiral áurea, foi possível desenvolver três diferentes modelos de aletas para o rotor, denominadas como aleta reta (rotor 1), aleta curvada (rotor 2) e aleta mais curvada (rotor 3)...

Infecciones asociadas a dispositivos de soporte circulatorio mecánico / Ventricular assist device-related infections

El dispositivo de asistencia ventricular asistida (DAV) se utiliza como terapéutica final o puente al trasplante cardíaco. La tasa de complicaciones infecciosas asociada a este dispositivo es elevada. La experiencia con este tipo de complicación en pediatría es escasa. Objetivo: conocer las características clínicas, microbiológicas y de evolución de pacientes con DAV. Material y métodos: pacientes internados en el Hospital Garrahan desde marzo del 2006 a marzo 2014 con DAV. Estudio retrospectivo, descriptivo. Se analizaron: edad, sexo, tipo de enfermedad de base, características clínicas, microbiológicas y de evolución de los pacientes con DAV. Resultados: se incluyeron 33 pacientes. La mediana de edad fue 79 meses (rango:13-133). La indicación de colocación del DAV fue miocardiopatía dilatada en el 81.8% (27). Los días acumulados de uso del DAV fue de 4.638 días. Diecisiete pacientes (51.5%) presentaron 23 episodios de infección. La infección pericánula se presentó 10 casos (43.4%), bacteriemias primarias en 4 (17.4%), bacteriemia asociada a catéter de corta permanencia 5 (21.7%), mediastinitis 3 (13%) y un caso de sepsis (4.3%). Los microorganismos prevalentes fueron los cocos gram positivos. Fallecieron 12 pacientes en DAV a la espera del trasplante, uno de ellos con sepsis y mediastinitis por S. aureus meticilino sensible. Conclusiones: La infección asociada a DAV fue frecuente en nuestros pacientes y dentro de ellas la infección pericánula fue la más común. Los cocos gran positivos fueron los microorganismos predominantes. Los pacientes con mayor tiempo de permanencia del DAV presentaron varios episodios de infección. Las infecciones asociadas al DAV no impidieron el éxito del trasplante cardíaco (AU)

Research on magnetic coupling centrifugal blood pump control based on a self-tuning fuzzy PI algorithm / 生物医学工程学杂志

The purpose of this paper is to report the research and design of control system of magnetic coupling centrifugal blood pump in our laboratory, and to briefly describe the structure of the magnetic coupling centrifugal blood pump and principles of the body circulation model. The performance of blood pump is not only related to materials and structure, but also depends on the control algorithm. We studied the algorithm about motor current double-loop control for brushless DC motor. In order to make the algorithm adjust parameter change in different situations, we used the self-tuning fuzzy PI control algorithm and gave the details about how to design fuzzy rules. We mainly used Matlab Simulink to simulate the motor control system to test the performance of algorithm, and briefly introduced how to implement these algorithms in hardware system. Finally, by building the platform and conducting experiments, we proved that self-tuning fuzzy PI control algorithm could greatly improve both dynamic and static performance of blood pump and make the motor speed and the blood pump flow stable and adjustable.

Numerical assessment of impeller features of centrifugal blood pump based on fast hemolysis approximation model / 生物医学工程学杂志

The impeller profile, which is one of the most important factors, determines the creation of shear stress which leads to blood hemolysis in the internal flow of centrifugal blood pump. The investigation of the internal flow field in centrifugal blood pump and the estimation of the hemolysis within different impeller profiles will provide information to improve the performance of centrifugal blood pump. The SST kappa-omega with low Reynolds correction was used in our laboratory to study the internal flow fields for four kinds of impellers of centrifugal blood pump. The flow fields included distributions of pressure field, velocity field and shear stress field. In addition, a fast numerical hemolysis approximation was adopted to calculate the normalized index of hemolysis (NIH). The results indicated that the pressure field distribution in all kinds of blood pump were reasonable, but for the log spiral impeller pump, the vortex and backflow were much lower than those of the other pumps, and the high shear stress zone was just about 0.004%, and the NIH was 0.0089.

Asistencia circulatoria mecánica / Mechanical circulatory support

La insuficiencia cardiaca constituye una verdadera epidemia a nivel mundial, y Chile no es la excepción. Como respuesta, la medicina ha ido ofreciendo un número cada vez mayor de alternativas para enfrentarla, con mejoras significativas en el tratamiento farmacológico, dispositivos de resincronización cardiaca y diferentes alternativas quirúrgicas, todo lo cual ha mejorado la sintomatología y ha prolongado parcialmente la supervivencia de esta patología en las fases iniciales. Sin embargo en las fases más avanzadas de esta enfermedad, sólo el trasplante cardiaco y actualmente la asistencia circulatoria, han demostrado una mejoría significativa de la supervivencia de este complejo grupo de pacientes. En esta revisión, intentamos revisar en profundidad los aspectos epidemiológicos, clínicos y terapéuticos en el enfrentamiento de esta patología, haciendo hincapié en diferentes aspectos quirúrgicos y en la indicación y manejo de la asistencia circulatoria mecánica, aspectos que son fundamentales a la hora de usar en forma segura esta nueva tecnología.

Heart failure is an epidemic worldwide disease, affecting mainly developed countries. In response, medicine has been offering an increasing number of treatment alternatives with significant improvements in drug therapy, cardiac resynchronization devices and surgical alternatives, all of which have improved symptoms and prolonged survival in the early stages of this pathology. However, in final stages, only heart transplantation has shown significant improvement in survival, and in the last years, Mechanical Circulatory Assistance has shown good results in this complex group of patients. In this article we review epidemiological, clinical and therapeutic aspects of Mechanical Circulatory Support, emphasizing on indications and contraindications, management, quality assurance and education of this therapeutic alternative for heart failure.

Atenuação da remodelação ventricular após infarto agudo do miocárdio / Attenuation of ventricular remodeling after myocardial acute infarction

Após o infarto agudo do miocárdio podem ocorrer complexas alterações da arquitetura ventricular, envolvendo tanto a região infartada como a região não infartada. Há alguns anos, essas alterações passaram a ser designadas como remodelação ventricular pós-infarto. Do ponto de vista clínico, a remodelação está associada ao pior prognóstico após a oclusão coronária. Assim, a remodelação predispõe o coração infartado à ruptura ventricular e é o substrato fisiopatológico para a posterior formação do aneurisma ventricular. Cronicamente, a remodelação está associada com maior prevalência de arritmias malignas, principalmente a taquicardia ventricular sustentada e a fibrilação ventricular. O aspecto mais relevante da remodelação pós-infarto, no entanto, é que esse processo desempenha papel fundamental na fisiopatologia da disfunção ventricular. Aspecto a ser considerado refere-se ao fato de que a evolução do processo de remodelação pode ser modificado por meio de diversas intervenções terapêuticas. Entre as estratégias para atenuar a remodelação ventricular destacam-se: terapia de reperfusão, inibidores da enzima conversora da angiotensina e antagonistas da angiotensina II, betabloqueadores, antagonistas da aldosterona e dispositivos de assistência circulatória.

After acute myocardial infarction (AMI), complex changes in ventricular architecture may occur involving the infarcted and the non-infarcted region. This set of adaptations, which includes changes in the composition, mass, volume and geometry of the heart, is known as myocardial remodeling. In relation to clinical significance, the intensity of the ventricular remodeling process is directly associated with worse prognosis, due to the higher incidence of aneurysm formation, ventricular rupture and arrhythmia, and is also associated with the progression of ventricular dysfunction. A relevant aspect to be considered is that a number of strategies have been employed to prevent or mitigate the process of ventricular remodeling following AMI, for instance: reperfusion therapy, angiotensin converting enzyme inhibitors and angiotensin II antagonists, beta-adrenergic receptor blockade, aldosterone antagonists, and left ventricular assist devices.

Percutaneous Transseptal Left Atrial Drainage for Decompression of the Left Heart in an Adult Patient during Percutaneous Cardiopulmonary Support

A 28-year-old male with hemophagocytic lymphohistiocytosis presented with left ventricular dysfunction and cardiac arrest. Percutaneous cardiopulmonary support (PCPS) was initiated, but left heart distension developed with associated aggravation of pulmonary edema. Percutaneous transseptal left atrial sheath (28-Fr) drainage was incorporated into the PCPS venous circuit under fluoroscopic guidance to enable left heart decompression 1 days after PCPS initiation. The patient's pulmonary edema improved markedly, and distention of his left heart diminished. He was successfully weaned from PCPS 5 days later. Percutaneous transseptal left atrial drainage with large venous cannulae is feasible and effective in decompressing the left heart in adult patients during PCPS.

Current Mechanical Circulatory Support Devices for End Stage Heart Failure

Mechanical circulatory support is necessary when heart failure becomes refractory to medical support. It is typically instituted when organ dysfunction occurs as a result of hypoperfusion. Enthusiasm has recently developed for the role of mechanical circulatory support in the ever-growing population of heart failure patients. Indeed, efforts in developing this technology have allowed for the relatively recent development of a variety of complete circulatory support devices. The use of left ventricular assist devices (LVADs) in patients with advanced heart failure results in a clinically meaningful survival benefit and an improved quality of life, and LVADs could be an acceptable alternative therapy for selected patients who are not candidates for cardiac transplantation.

Assistência circulatória mecânica: porquê e quando / Mechanical circulatory support: why and when

A insuficiência cardíaca tem avançado ao longo dos últimos anos tendo em vista o envelhecimento da população, o maior índice de sobrevida após o infarto agudo do miocárdio pelo uso dos trombolíticos, o avanço nas operações cardíacas e a melhora no diagnóstico das cardiomiopatias...

Heart failure has advanced throughout last years due to the aging of population, the higher survivel rate after acute myocardial infarction due to trombolitics use, the advance in heart surgeries and the improvement in cardiomyopathies diagnosis...

Artificial muscle and its prospect in application for direct cardiac compression assist / 生物医学工程学杂志

Artificial heart is an effective device in solving insufficient native heart supply for heart transplant, and the research and application of novel actuators play an important role in the development of artificial heart. In this paper, artificial muscle is introduced as the actuators of direct cardiac compression assist, and some of its parameters are compared with those of native heart muscle. The open problems are also discussed.

Avaliação do emprego clínico do dispositivo de assistência ventricular InCor como ponte para o transplante cardíaco / Evaluation of the clinical application of the ventricular assist device type Incor as a bridge to cardiac transplantation

Apesar dos crescentes avanços no controle e tratamento da insuficiência cardíaca, sejam eles na área clinica ou cirúrgica, o tratamento definitivo permanece sendo o transplante cardíaco. No entanto, o transplante cardíaco tem enfrentado o grave problema da escassez de doadores. Atualmente, estima-se que entre 20% e 40% dos pacientes selecionados falecem na fila de espera em todo o mundo sendo que a maioria, por falência circulatória progressiva. Para esses pacientes, a utilização de dispositivos de assistência circulatória mecânica é, muitas vezes, a única possibilidade de sobrevivência durante a espera do doador. No Brasil, a experiência com o emprego de métodos de assistência circulatória mecânica no tratamento do choque cardiogênico é pequena. Paralelamente, a expectativa de vida dos pacientes nesta situação, em particular os de etiologia chagásica, é muito limitada, e nenhum programa regular foi ainda introduzido com a finalidade de utilizar estes dispositivos no tratamento do choque cardiogênico refratário, especialmente como ponte para o transplante cardíaco. Objetivos: O objetivo deste estudo é determinar a viabilidade e segurança do implante do DAV-InCor como ponte para o transplante cardíaco, avaliando o seu desempenho hemodinâmico, a evolução clínica e as alterações da resposta inflamatória dos pacientes submetidos a este procedimento. Métodos: Este estudo foi realizado em pacientes que estavam na fila de espera para o transplante cardíaco, no período de outubro de 2003 a abril de 2006, e se apresentavam em quadro clínico de choque cardiogênico refratário. Durante os primeiros dias, foram analisadas as medidas de pressão capilar pulmonar (PCP), pressão de artéria pulmonar (PAP), pressão venosa central (PVC), débito cardíaco e índice cardíaco (IC). O cálculo do fluxo indexado era obtido pela divisão entre o fluxo do dispositivo pela superfície corpórea...

Cardiac transplantation faces a serious problem of lack of donation. Between 20 and 40% of the listed patients died while waiting for heart transplantation, most of them because of progressive heart failure. For these patients, the use of mechanical circulatory assist devices is the only choice of surviving during that time. In Brazil, the experience with mechanical circulatory support is limited and there is no regular program of the use of these devices as bridge to heart transplantation. Objectives: To evaluate the hemodynamic performance and the systemic inflammatory response during the clinical application of the ventricular assist device type InCor (DAV-InCor) as bridge to heart transplantation. Methods: Between October 2003 and April 2006, 11 patients on the waiting list for heart transplantation have hemodynamic deterioration to refractory cardiogenic shock. Hemodinamic profile (cardiac index, capilar pressure, pulmonary artery pressure and central venous pressure) was analised during early post-operative days. Serum levels of central venous saturation, lactate, urea, creatinin, bilirrubin and lacti desidrogenase were measured every day Blood drawn from patients for 3 days and once a week was assayed for levels of BNP, interleukin 6, interleukin 8, and tumor necrosis factor-alfa. Results: During the study, 11 patients listed for cardiac transplantation as urgent status have deteriorated to refractory cardiogenic shock. Seven of these patients were submitted to DAV-InCor implantation for left ventricular assistance. The etiologic diagnosis was Chagas' disease in 5 patients (71%) and idiopathic dilated cardiomyopathy in 2 (29%). There were 5 male and 2 female...

Establishment of a pig model of chronic ally enhanced external counterpulsation / 南方医科大学学报

<p><b>OBJECTIVE</b>To establish a pig model of chronic external counterpulsation.</p><p><b>METHODS</b>Twelve pigs were anaesthetized with sodium pentobarbital (< or =30 mg/kg.b.w.) and 846 mixture (< or =0.1 ml/kg.b.w.) and counterpulsed in a lateral position for 2 h every two days (totally 36 h) with 0.025 to 0.04 MPa/cm(2) pressure.</p><p><b>RESULTS</b>External counterpulsation was successfully completed in all the animals. Combined administration of sodium pentobarbital and 846 mixture resulted in good anesthetic effect with reduced anesthetic dosage and minimal side effect on the viscera (the liver, kidney and heart, etc).</p><p><b>CONCLUSION</b>The pig model of chronic external counterpulsation has been successfully established. Combined use of sodium pentobarbital and 846 mixture is recommended for chronic external counterpulsation.</p>