Perfusion 

About: Perfusion is an academic journal published by SAGE Publishing. The journal publishes majorly in the area(s): Cardiopulmonary bypass & Extracorporeal membrane oxygenation. It has an ISSN identifier of 0267-6591. Over the lifetime, 3018 publications have been published receiving 34216 citations.

Research using qualitative, quantitative or mixed methods and choice based on the research.

Abstract: Research is fundamental to the advancement of medicine and critical to identifying the most optimal therapies unique to particular societies. This is easily observed through the dynamics associated with pharmacology, surgical technique and the medical equipment used today versus short years ago. Advancements in knowledge synthesis and reporting guidelines enhance the quality, scope and applicability of results; thus, improving health science and clinical practice and advancing health policy. While advancements are critical to the progression of optimal health care, the high cost associated with these endeavors cannot be ignored. Research fundamentally needs to be evaluated to identify the most efficient methods of evaluation. The primary objective of this paper is to look at a specific research methodology when applied to the area of clinical research, especially extracorporeal circulation and its prognosis for the future.

The Case for the Case.

Abstract: The popular television series Downton Abbey recently concluded after six seasons of being viewed in the UK, United States and other parts of the world. This award-winning series told a story of a fictional aristocratic British family and their domestic servants in the post-Edwardian era in Yorkshire. The series was set in the early twentieth century and follows the trials and tribulations of the family as the world emerges from World War I and into the 1920s. Over the six seasons, the story line has had its share of love, lust, violence, justice and, most important of all, controversy and the challenges related to change. Although fictitious, Downtown Abbey tells a “story”. In scientific endeavors, non-fictional events are also described in many forms, one being the case report. A case study identifies a person, a problem, a setting, a treatment or intervention and some form of finality; if a similar case has been previously published, the current one being reported can easily be put in context. In some situations, the ending is rewarding, happy and positive; in other situations, it is sad, disappointing or unsuccessful. Often, a case study identifies a unique clinical problem or challenge which, in some forms, may be a rare event. Often, the clinical problem is a mystery. The problem may even be undiagnosed pathophysiology and the treatment may be vague or inconclusive. However, these individual case studies typically identify the need for further research and investigation on the clinical problem or issue. Research purists might argue that case studies are not overly valid because it is difficult to make a generalized conclusion in a single setting. Controlled, randomized, blinded studies might be the best form to study any scientific hypothesis, yet these studies are often difficult to control and involve many patients, thus, are expensive to conduct and analyze; because of these constraints, they cannot be reported as quickly as a case report. Prospective studies with designated experimental cohorts with measureable variables and statically comparable groups are often used to test a hypothesis in a controlled setting. However, these studies often fall short of proving their hypothesis for they often require a large study population number to suggest a conclusion or advantage. Small pilot studies are just that: small. Pilot studies can be used to show proof of concept, but it can be a stretch to make any widespread clinical conclusion on an n=5. The question arises if a single case study or even a small cohort study has any validity. The single case report does identify a unique problem, a method of interaction and a result. Often, the most meaningful case studies are those that are unsuccessful, but raise questions that usually lead to even more challenges. In this issue of Perfusion, in addition to the regular collection of scientific publications, there are three case studies that cover three unique topics. The first by Benetis et al. describes the ECMO course of an 18-yearold woman who developed sepsis, respiratory distress and disseminated intravascular coagulation postpartum after an urgent C-section. Swol et al. report on the use of ECMO support after trauma with an associated finding of open tuberculosis. The third case study by Tran et al. describes the operative management of a HeartMate II (HMII) left ventricular assist device in a patient with a non-compliant left ventricle and a reduced right ventricular end-diastolic volume. As a result of the surgical procedure, the right and left ventricular stroke volumes were different, resulting in an inaccuracy in the HMII flow rate display. Certainly, in each of these cases, the problem or occurrence is rare, yet each report gives clinician readers an insight on optional treatments and raises questions that may be grounds for further study. In summary, case reports are a time-honored tradition in medicine aimed at better patient care and, as such, they constitute an important part of the published literature embodied in our journal.

Inflammatory cytokine inhibition of erythropoiesis in patients implanted with a mechanical circulatory assist device.

Abstract: Mechanical circulatory assist devices (MCADs) are increasingly utilized independently of cardiac transplantation in the management of heart failure. Though MCAD use incorporates inherent mechanical risks, the inevitable onset of chronic anemia, with its associated morbidity and mortality, is also a significant concern. MCAD support has been correlated with elevated plasma levels of inflammatory cytokines TNF-alpha, IL-1beta, and IL-6, which have separately been found to inhibit erythropoietin (Epo)-induced erythrocyte (RBC) maturation. Previous analysis of hematological parameters for MCAD-supported patients concluded that an amplified inflammatory response impedes RBC proliferation and recovery from hemolytic anemia. Additional analysis may bolster this assertion. Hemoglobin concentration (HC), RBC distribution width (RDW), mean cell volume (MCV), and cardiac index were retrospectively analysed for 78 MCAD-supported patients implanted for greater than 30 days at the University of Arizona Health Sciences Center from 1996 to 2002. Analysis confirms that the HC, a conventional marker for anemia, declines with MCAD placement and remains below the clinically defined, minimum normal value. Inversely, the RDW rises above maximum normal measure, signifying an increased fraction of juvenile RBCs. The MCV remains unchanged and within normal limits, demonstrating adequate substrate for RBC formation. MCAD performance also stabilizes as adequate perfusion returns. These results further support our previously published conclusion that a sufficient response of erythropoiesis occurs in reaction to the onset of anemia by an increased production of immature RBCs. However, the cells never fully mature and join circulation. The patient's inflammatory cytokine response to the implanted device most likely mediates the chronic MCAD-induced anemia by inhibition of Epo effects.

A successful modification of ultrafiltration for cardiopulmonary bypass in children.

Abstract: Total body water (TBW) is increased after cardiopulmonary bypass (CPB) resulting in tissue oedema and organ dysfunction. Ultrafiltration has been used to reduce this accumulation of water, although conventional ultrafiltration seemed ineffective in reducing the rise in TBW after CPB in our clinical experience. We describe a modified technique in which ultrafiltration is performed in the first 10 minutes after the patient is weaned from bypass, returning nearly all the blood in the circuit to the patient and elevating the haematocrit (Hct) to any predetermined level. We carried out a pilot study on 21 children aged 4-144 months undergoing open-heart surgery and CPB for congenital heart defects. They were divided into three comparable groups: (1) controls (n = 6); (2) conventional ultrafiltration (n = 7); and (3) modified ultrafiltration (n = 8). TBW (bio-impedance), Hct, osmolality, mean corpuscular volume and mean corpuscular haemoglobin concentration were recorded at frequent intervals. Control patients showed elevation of TBW by 18.2% median (range 14.5-20.3), conventional ultrafiltration by 12.4% (7.9-15.0), modified ultrafiltration by 5.7% (4.5-7.1) (p less than 0.0001 compared to controls, p. less than 0.005 compared to conventional ultrafiltration, Mann-Whitney U test). Hct could be elevated to preoperative levels only by the modified method. Mean corpuscular volume, and mean corpuscular haemoglobin concentration osmolality were unaltered. Ultrafiltration by the modified method was more effective than conventional ultrafiltration in reducing the rise in TBW and elevating Hct after CPB.

Systemic inflammation and cardiac surgery: an update.

Abstract: Cardiac surgery with cardiopulmonary bypass (CPB) is associated with the development of a systemic inflammatory response that can often lead to dysfunction of major organs. The systemic inflammation can be assessed intra- and postoperatively by measuring concentrations of inflammatory mediators in plasma and tissues. These concentrations, however, do not always correlate with the degree of observed organ dysfunction. Various strategies have been used to reduce inflammatory phenomena in patients undergoing CPB. Cardiac surgery without CPB has been performed increasingly with satisfactory results over the past few years. Attenuation of systemic inflammation and improved outcome in high risk patients are potential benefits of this technique. The emergence and expanding performance of cardiac surgical procedures without the use of CPB has given us an excellent tool to investigate the relative importance of CPB as a cause of systemic inflammation. Aprotinin is a protease inhibitor which is used in cardiac surgical patients for its haemostatic effects. Aprotinin has anti-inflammatory properties, the nature of which have not been completely clarified. This article presents a summary of the published literature investigating inflammatory response and organ dysfunction in patients who have cardiac surgery without CPB. It also presents an overview of recent data on the anti-inflammatory action mechanisms of aprotinin.