A structured blood conservation program in pediatric cardiac surgery.

OBJECTIVE: The limitation of alternative transfusion practices in infants increases the benefits of blood conservation. We analyzed the efficacy of a structured program to reduce transfusions and transfusion-associated complications in cardiac surgery PATIENTS AND METHODS: Our pediatric surgery database was reviewed retrospectively, comparing outcomes from two different time periods, after the implementation of an effective blood conservation program beginning in March 2014. A total of 214 infants (8.1±3.4 months) who underwent biventricular repair utilizing CPB (Group 1 - Blood conservation) were studied in a 12-month period (March 2014-February 2015) after the implementation of the new program, and compared with 250 infants (7.91±3.2 months) (Group 2 - Control-No blood conservation) of the previous 12-month period (March 2013-February 2014). RESULTS: The proportion of patients transfused with red blood cells was 75.2% (N=188) in control group and reduced by 16.4% in the study group (58.8% - 126 patients, p <0.01). The mean number of transfusions was 1.25 ± 0.5 units per patient in control group and decreased to 0.7 ± 0.5 units per patient after the start of the program (p = 0.035). Cerebral oximetry demonstrated better follow-up during the operative period confirming less hemodilution in Group 1. Respiratory support, inotropic need and ICU stay were significantly better in the study group. CONCLUSIONS: These findings, in addition to attendant risks and side effects of blood transfusion and the rising cost of safer blood products, justify blood conservation in pediatric cardiac operations. Circuit miniaturization, ultrafiltration, and reduced postoperative bleeding, presumably secondary to higher fibrinogen and other coagulation factor levels, contributed to this outcome.

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

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.

Detection-loophole-free test of quantum nonlocality, and applications.

We present a source of entangled photons that violates a Bell inequality free of the "fair-sampling" assumption, by over 7 standard deviations. This violation is the first reported experiment with photons to close the detection loophole, and we demonstrate enough "efficiency" overhead to eventually perform a fully loophole-free test of local realism. The entanglement quality is verified by maximally violating additional Bell tests, testing the upper limit of quantum correlations. Finally, we use the source to generate "device-independent" private quantum random numbers at rates over 4 orders of magnitude beyond previous experiments.

Clinical impact and biomaterial evaluation of autologous platelet gel in cardiac surgery.

We compared the clinical efficacy of autologous platelet gel (APG) and gelatine (CONT), including biomaterial evaluation. In a prospective, randomized, controlled trial, 64 patients undergoing complex coronary artery bypass graft (CABG) surgery and/or aortic surgery, in whom the surgeon was able to identify a bleeding site for which conventional means to stop bleeding were impractical or proved unsuccessful, were enrolled. Aortic punch biopsy from each patient was harvested in explant cell (EC) culture media. Hemostasis success for the "oozing" category was 89% in APG and 60% in CONT (p< 0.05). For the "heavy bleeding" category, the success rates were 92% in APG and 45% in CONT (p<0.01). Contact of gelatine inhibited EC proliferation and APG increased cell cycling and EC quantity. Phagocytic capacity (PC) was significantly higher in the APG group (p<0.001). APG was significantly better than CONT with respect to hemostatic success rate, effects on wound healing and increased resistance to infection (PC).

Strategic leukofiltration in cardiac surgery.

Systemic inflammatory response syndrome (SIRS) with activation of molecular cascades, cell activation, accumulation of interstitial fluid, organ dysfunction and, occasionally, organ failure is still a commonly recognized consequence of cardiac surgery. SIRS leads to costly complications and several strategies intended to ameliorate the symptoms that have been studied, including leukocyte reduction, using filtration. Although, the body of work suggests that leukoreduction attenuates SIRS, discrepancies remain within the literature. The recent literature is reviewed highlighting the areas where concordance is lacking. In our study, on the basis of indirect indicators of SIRS, platelet function by thromboelastography biomaterial evaluation by light and scanning electron microscopy, we present our conclusions regarding clinical outcomes and the role of leukofiltration.

MAST system: a new condensed cardiopulmonary bypass circuit for adult cardiac surgery.

There have been many refinements in cardiopulmonary bypass (CPB) techniques over the past few decades specific to design, materials and function. Despite these improvements, use of the standard length circuit tubing and pump oxygenator alter cellular, biochemical and rheological properties by inducing a systemic inflammatory response, persisting well into the early postoperative phase. We have designed a new condensed CPB circuit, the MAST system, where the oxygenator and the pumps are brought closer to the operating table (within 30 inches) with the help of a series of telescopic swivel steel poles to which they are attached. The control console is retained at the usual remote location of 2ft behind the MAST system. This configuration accomplishes a decrease in tubing length, priming volume and blood circulatory time within the extracorporeal circuit. Early experience of a hundred consecutive cases utilizing the MAST CPB system is presented along with a comparative analysis of prime volume, hemodilution and transfusion parameters of MAST system vs the low prime system, which is another newly developed CPB circuit utilizing a pediatric oxygenator to reduce prime volume and hemodilution.

Isolated extra-corporeal coronary perfusion circuit for use during off-pump coronary artery bypass grafting.

Cardiovascular surgery would not have developed into its present form without the heart-lung machine. In coronary artery bypass grafting (CABG), cardiopulmonary bypass allows accurate, all site, complete revascularization in a way convenient to the surgeon. The aim of this circuit is to find new ways to reduce invasiveness of CABG and to create new basis conditions for successful coronary bypass grafting on the beating heart. Manipulation of the heart compromises collateral coronary flow, especially to critically narrowed coronaries. This circuit standardizes our method for perfusing blood through the coronary bypass grafts with controlled positive pressure as each distal anastomosis is made, and it preserves collateral coronary flow, while facilitating construction of the remaining distal anastomoses.

Post cardiopulmonary bypass bleeding: an introductory review.

Cardiac surgery requiring cardiopulmonary bypass (CPB) has increased in both number and safety over the past four decades. Postoperative bleeding continues to be a major cause of perioperative morbidity. The reported incidence varies from 4-32%. This paper reviews the preoperative evaluation and specific hemostasis defects associated with cardiac surgery and extracorporeal circulation. Monitoring of anticoagulation and coagulation, methods to decrease the alterations of the coagulation system, as well as the specific therapy for and risks of post-CPB bleeding are also discussed.

The United Kingdom pre-hospital study of active compression-decompression resuscitation.

This prospective, controlled trial with crossover group design compares the effectiveness of active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) and standard CPR on the outcomes of victims of prehospital cardiac arrest. In three UK cities, victims of non-traumatic, out of hospital cardiac arrest, over the age of 8 years received either standard or ACD-CPR on arrival of ambulance personnel. Main outcome measures were return of spontaneous circulation, survival to be admitted to the intensive care unit, survival to hospital discharge, and neurological outcome. A total of 576 patients (STD-CPR, n=309; ACD-CPR, n=267) were analysed. The treatment groups were similar with respect to age, gender, proportion of witnessed arrests, initial cardiac rhythm, and call to advanced life support interval. The proportion of patients receiving bystander CPR was higher in the ACD group (37.1% vs. 28.5%; P=0.028). The interval between collapse and defibrillation was longer in the ACD group (12.3 min vs. 10.4 min; P=0.028). There was no difference between the STD-CPR and ACD-CPR groups in survival to admission to the intensive care unit (13.6% vs. 13.8%; P=0.93) or hospital discharge (4.8% vs. 6.0%; P=0.67). There was no difference between the groups with respect to the neurological outcome of those patients surviving to hospital discharge. Analysis of important subgroups also showed no benefit for ACD-CPR. We conclude that there was no improvement in outcome with ACD-CPR when used by ambulance personnel in Cardiff and Portsmouth.

Mechanisms of respiratory tissue injury from cigarette smoking.

Cigarette smoking can be viewed as a chronic inflammatory disorder of the lower airways. Two of the major lung injuries that can result are chronic bronchitis and emphysema. Chronic bronchitis is characterized by chronic mucus hypersecretion and cough; emphysema is a destructive process of the alveolar spaces. Tissue injury may result from the actions of degradative enzymes derived from such inflammatory cells as neutrophils and monocytes. In addition, oxidative injury from inflammatory cells and from oxidants in smoke may participate in the pathogenesis of these smoking-related illnesses.

High-flow femoro-femoral bypass utilizing small cannulae and a centrifugal pump on the venous side.

Femoro-femoral bypass is an established technique in the armamentarium of cardiac surgeons, but poor venous drainage usually restricts the flow rate that can be achieved. We describe a technique whereby full flow ( greater than 2.41 l/min/m 2 femoro-femoral bypass) can be achieved with a 17 F arterial and a single 21 F venous cannula placed percutaneously or via a cut-down. Transoesophageal echo is used to position the tip of the venous cannula accurately in the right atrium. The circuit includes a centrifugal pump on the venous side, pumping into a reservoir; a conventional roller pump delivers blood through the arterial cannula. A parallel arrangement allows the centrifugal pump to be excluded from the circuit at any stage. The system allows flow rates over 2.4 l/min/m 2 despite the size of the venous cannula; without the centrifugal pump working maximal flow rates are under 1.5 l/min/m 2. The right side of the heart is totally decompressed and there is no need to add volume or vasopressors to maintain the desired full flow rate. Once the chest is open, perfusion may continue as before or gravity drainage can be utilized after stopping the centrifugal pump; venous return may be augmented by placing additional cannulae. If desired, slowing drainage by the centrifugal pump temporarily permits the blind placement of a coronary sinus cannula without entraining air.(ABSTRACT TRUNCATED AT 250 WORDS)

Legionella pneumophila: denizen of defenders.

Legionella pneumophila, the causative agent of legionellosis, is an intracellular parasite of human monocytic cells and neutrophils. The life cycle of Legionella within phagocytic cells is distinct from that of other bacterial pathogens. Adherence of L pneumophila to phagocytes is mediated by attachment of complement proteins to the Legionella cell surface, followed by binding to complement receptors of phagocytes. Opsonized Legionella also may enter phagocytes after engagement of the Fc receptors. Within the host cell, the parasites reside in a membrane-bound vacuole that does not fuse with lysosomes. Activation of mononuclear phagocytes by the cell-mediated immune system serves to limit intracellular bacterial growth. Polymorphonuclear leukocytes are better at killing L pneumophila than are macrophages. However, Legionella also can invade and parasitize granulocytes. Although significant progress has been made in understanding some aspects of the pathogenesis of legionellosis, we know very little about the mechanisms by which these facultative intracellular parasites avoid killing by host defense mechanisms. This is an important area for future research and should lead to a better understanding of host-parasite interactions.

Legionella pneumophila inhibits protein synthesis in Chinese hamster ovary cells.

Legionella pneumophila is a gram-negative facultative intracellular parasite that causes Legionnaires disease. To explore the interactions between L. pneumophila and host cells, we have developed a continuous cell line model of infection. We show that about 80% of Chinese hamster ovary (CHO) cells were associated with L. pneumophila after incubation for 3 h at a multiplicity of infection of 20 bacteria per cell. Within 3 to 4 h of incubation with L. pneumophila, protein synthesis of CHO cells was markedly inhibited, as shown by the reduction of incorporation of radiolabeled amino acids into proteins. L. pneumophila did not inhibit transport of amino acids or cause degradation of newly synthesized proteins in CHO cells. Cytochalasin D blocked internalization of L. pneumophila by CHO cells, yet CHO cell protein synthesis was inhibited. These results indicated that L. pneumophila could inhibit host protein synthesis from the cell exterior. L. pneumophila that had been killed with antibiotics prior to incubation with CHO cells still inhibited protein synthesis, indicating that the inhibition of CHO cell protein synthesis occurred in the absence of de novo protein synthesis by L. pneumophila.

Selective increase of antioxidant enzyme activity in the alveolar macrophages from cigarette smokers and smoke-exposed hamsters.

Oxidants from cigarette smoke or those produced by phagocytes are implicated in the pathogenesis of emphysema. We reasoned that augmentation of antioxidant enzymes in cigarette smokers may be important in restricting direct and indirect oxidant damage to alveolar structures. Accordingly, we studied the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSHPx), in alveolar macrophages (AM) from cigarette smokers and from smoke-exposed hamsters. The activities of these antioxidant enzymes were compared with the activities found in AM from nonsmoking control subjects. The activities of SOD and CAT from AM of smokers and smoke-exposed hamsters were twice that found in control subjects (p less than 0.01), but there was no change in the activity of GSHPx. Using the hamster model, we found that filtration of smoke attenuated the increase in antioxidant activities, and that after smoking cessation, the increased activities had returned to those found with control subjects. An adaptive response was further suggested by prolonged survival of smoke-exposed hamsters in normobaric hyperoxia (O2 greater than 95%). Chronic smoke exposure in humans or hamsters causes increased SOD and CAT activities in AM. This augmented activity may serve as a mechanism to limit oxidant-mediated damage to alveolar structures.

Characterization of scavenger receptor activity in resident human lung macrophages.

We characterized scavenger receptor pathways of human alveolar macrophages and cultured monocytes using radiolabeled maleylated bovine serum albumin (MAL-BSA) and acetylated low-density lipoprotein (Ac-LDL) as ligands. Human alveolar macrophages and cultured human monocytes degraded both MAL-BSA and Ac-LDL. Both ligands were bound and degraded in a specific and saturable fashion. Specificity of degradation was tested using excess MAL-BSA and Ac-LDL, polyanionic compounds, and alpha-casein as inhibitors. Alveolar macrophages utilized the classical scavenger receptor pathway to degrade MAL-BSA and Ac-LDL. In contrast, cultured monocytes utilized two receptor pathways to degrade MAL-BSA: the classical scavenger receptor pathway and a secondary alpha-casein-inhibitable pathway. These results demonstrate differences in the activities of receptor systems in cultured monocytes compared to alveolar macrophages.

Leukocyte function and chronic bronchitis.

Chronic bronchitis is a condition of mucous hypersecretion. It represents an interface between airway structures, cigarette smoke, and inflammatory cells. Chronic bronchitis is a late complication of smoking, typically occurring after 30 pack years. Stable patients have mucous hypersecretion and little evidence of acute inflammation. In contrast, during acute attacks of bronchitis, an intense accumulation of neutrophils occurs in the airways. Mechanisms of injury to airway structures include chemicals and reactive oxygen species within cigarette smoke, and secreted products of recruited neutrophils. Recent studies demonstrate that secreted products of polymorphonuclear leukocytes (PMNs) can cause secretory cell metaplasia and increase mucous production. Thus, the role of the PMN in chronic mucous hypersecretion appears to be a significant one. Cessation of cigarette smoking remains a most important aspect of caring for patients with chronic mucous hypersecretion.

Landmarks of tobacco use in the United States.

The idea of inhaling smoke from cigarettes is historically new, actually less than a century old. Consumption of tobacco has changed from chewing tobacco and pipe smoking to smoking cigarettes; smokeless tobaccos are growing tremendously in popularity. The modern smoker is confronted with a highly engineered, complex composite of specially designed paper, tobacco, tobacco additives, and a panoply of filters, a far cry from the hollow reed Columbus saw. Tobacco has been glibly referred to as a form of revenge by native Indians. There is little similarity between ceremonial use of tobacco by the Indians and the robotic puffing of the modern smoker. The real culprit is the cigarette.