Durable mechanical circulatory support devices

Individuals afflicted with advanced systolic heart failure who have become unresponsive to standard medical and electrical therapies are categorized as having American Heart Association stage D heart failure. The high mortality rates for medically treated stage D heart failure have not improved in the last 10 years, and patients at this advanced stage require either palliative measures or surgical management of heart failure. In recent years, surgically implanted ventricular assist devices (VADs) have become available for long-term use and are now commonly used as a therapy for advanced heart failure. The data generated from this early experience have clearly shown that VADs improve survival and quality of life in patients with advanced heart failure when implanted as a temporary measure or as long-term support. However, with a growing heart failure population, there is much work to be done to continually improve VAD technology, patient selection criteria, and postimplantation management to define the optimal role for assist devices in the management of systolic heart failure.     

唑来膦酸联合VAD方案治疗多发性骨髓瘤骨疼的疗效分析

目的观察唑来膦酸联合VAD方案化疗治疗多发性骨髓瘤骨疼疗效。方法将确诊后的多发性骨髓瘤骨疼的患者随机分2组,每组20例。唑来膦酸组联合VAD方案,对照组单纯VAD(长春新碱+阿霉素+地塞米松)方案化疗。观察骨疼效果。结果唑来膦酸联合VAD组骨疼缓解率为95,单纯化疗组缓解率86。结论唑来膦酸联合VAD化疗治疗多发性骨髓瘤骨疼的缓解率较单纯化疗组高,差异有统计学意义。     

沙利度胺联合VAD方案治疗多发性骨髓瘤的疗效及对患者免疫功能的影响

目的 研究沙利度胺联合VAD方案治疗多发性骨髓瘤的疗效及对患者免疫功能的影响.方法 选取74例多发性骨髓瘤患者,根据分层随机分组法分为观察组和对照组,每组各37例.对照组采取VAD方案进行治疗,观察组在此基础上加以沙利度胺进行治疗.分析两组患者治疗前和治疗4个周期后免疫功能、骨髓瘤细胞、β2-微球蛋白、M蛋白、血红蛋白指标变化,比较两组患者的临床疗效和不良反应.结果 治疗4个周期后,观察组的CD4+CD25+、IL-6、TGF-β指标明显低于对照组,INF-γ/IL-10指标高于对照组,差异均有统计学意义(P<0.05).治疗4个周期后,观察组的骨髓瘤细胞、β2-微球蛋白、M蛋白指标明显低于对照组,血红蛋白明显高于对照组,差异均有统计学意义(P<0.01).观察组总有效率高于对照组(P<0.05).观察组和对照组的皮疹、感染、便秘、嗜睡等不良反应发生率比较差异无统计学意义(P>0.05).结论 在治疗多发性骨髓瘤中采取沙利度胺联合VAD方案能有效改善患者的免疫功能,临床疗效较好,不良反应属于轻度型,患者均可耐受.     

An integrative review of the literature on in-hospital worsening heart failure

A subset of patients hospitalized for acute exacerbation of chronic heart failure develop in-hospital worsening heart failure. The objective of this paper is to present an integrative review of in-hospital worsening heart failure, including definitions, incidence, prevalence, mechanisms, treatments, outcomes, and early identification by providers. A search of electronic databases was conducted from January 2000-August 2017 using multiple search terms. Papers were reviewed for relevance; retained papers were abstracted and data were reported in a narrative synthesis. Twenty papers were selected. Many papers were observational data from in-hospital events that occurred during research trials. There was great variability in in-hospital worsening heart failure definition, incidence, prevalence, and treatments offered. Despite rescue therapies, in-hospital worsening heart failure was associated with increased risk for longer hospital stays, higher readmission rates, and death. To date, there are no therapies that target the underlying mechanisms or minimize its occurrence.     

Considerations and Problems in the Development of the Mini-Spindle Pump

Abstract: The premise for the development of the mini-spindle pump, planned as an implantable device for assisted circulation, was to transport 4 L of water/min in mock circulation with a speed of 12–15,000 rpm against an afterload of 90 mm Hg. After calculations, the resulting first prototype had a spindle rotor with 3 threads (outer diameter, 18 mm; inner diameter, 6.2 mm; length, 45 mm) in a U-shaped housing, driven by an electric motor with a cooling system. In mock circulation, this pump moved 7.8 L of water/min at 18,000 rpm. To avoid animal experiments, its influence on the blood was tested in a Maxima oxygenator. The device circulated 4.2 L of blood/min with the same speed. Because of its high traumatic he-molysis rate (>250 mg% of free hemoglobin after 7 h of pumping), the rotor was modified, first without effect at 2.5 threads and then at 4 threads. In addition, in this third prototype, the flow direction was reversed. This prototype was more effective (4.3 L of blood/min at 12,000 rpm in the oxygenator) and the hemolysis rate, after a pumping duration of 8 h, could only be reduced to 180 mg% of free hemoglobin. As a result, a fourth prototype was developed (i.e., the U-shape of the housing was abandoned). This device functioned better than the third prototype (4.5 L of blood/min at 12,000 rpm in the oxygenator), but the blood trauma increased (220 mg% of free hemoglobin after 7 h of pumping). To find out if the oxygenator may be responsible for the hemolysis problem, the 16th prototype of the large spindle pump was tested in the oxygenator. The result was expected, the level of free plasma hemoglobin was high again (190 mg%). To verify the function of the third and the fourth prototype of the mini-spindle pump, 4 animal experiments were performed. Under normal cardiac conditions, the devices emptied the left ventricle up to 70% with a speed between 10,500 and 11,200 rpm, moving about 6 L of blood/min (afterload between 65 and 90 mm Hg). The hemolysis rates were between 32 and 90 mg% of free hemoglobin in the plasma.     

Development and Evaluation of Antithrombogenic Centrifugal Pump: The Baylor C–Gyro Pump Eccentric Inlet Port Model

Abstract: The Baylor C–Gyro Pump Eccentric Inlet Port Models (C1E) have been developed aiming for a longterm centrifugal ventricular assist device (VAD) as well as a cardiopulmonary bypass pump. The eccentric inlet port models are characterized by their unique inlet port and secondary impeller vanes. An inlet female pivot bearing, which was fixed to a supporting bar in the prototype model, is directly embedded into the ceiling of the pump casing. An inlet port is then placed off–center to avoid the bearing area, and it is angled between 0 to 90° from the upright position. In addition, small secondary vanes were incorporated into the impeller bottom to accelerate the washout flow behind the impeller. These features attained design objectives proposed for higher antithrombogenicity: a seal–less pump chamber, no stationary parts in the blood path, and acceleration of the secondary flow behind the impeller. The first in vivo experiment using C1E pumps showed excellent antithrombogenicity for up to 18 days when the experiment ceased due to severe infection in the calf.     

The Italian Artificial Heart Program

Abstract: In Italy, artificial heart development was promoted by virtue of a special program on technological and industrial development in areas related to cardiology and cardiosurgery. A first prototype series of electromechanical total artificial hearts (TAHs) and ventricular assist devices (VADs), with ball–screw–based actuation technology, has been developed, and preliminary bench tests and short–term animal implant experiments were performed. The project started with analysis and development of existing TAH and VAD models, and it included a fill–sensor–free control scheme and anatomical fitting studies using a three–dimensional computer model of the chest cavity. Second–generation prototypes are currently being developed, and they are scheduled for mediumterm bench and in vivo testing by early 1994.     

Competence,challenges and attitudes of bedside nurses caring for patients with left ventricular assist devices

ObjectivesWe aimed to describe the bedside registered nurses perceived competence, attitudes, and challenges surrounding the management of patients with left ventricular assist devices (LVAD) in the intensive care unit (ICU) and stepdown unit (SDU).Research methodology/designAn exploratory research was employed using a survey.SettingBedside participants were recruited via an electronic recruitment flyer circulated in online professional and social networking sites.Main outcome measuresItems consisted of a numeric rating scale, measuring competence and attitudes related to the management of patients with left ventricular assist devices. The one open-ended question asked the participants to write responses regarding challenges in left ventricular assist device care. Data were analysed using quantitative and qualitative analytics software.ResultsA total of 36 intensive care unit and 35 stepdown unit bedside nurse (n = 71) from six regions of the United States responded. Overall mean scores for competency and attitude domains were ≥ 7.0. Intensive care nurses scored higher in competence and attitude when compared to stepdown unit nurses care of short-term left ventricular assist devices. Competence and attitude were positively associated with years of experience. Five themes related to challenges in care were identified.ConclusionOverall, bedside nurses had satisfactory competence and attitudes surrounding the care of hospitalised left ventricular assist device patients.