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1
John, Alison Elizabeth. "Interleukin-8 and cardiopulmonary bypass." Thesis, University of Sheffield, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301551.
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Linden, Matthew D. "The haemostatic defect of cardiopulmonary bypass." University of Western Australia. School of Surgery and Pathology, 2003. http://theses.library.uwa.edu.au/adt-WU2006.0009.
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[Truncated abstract] Cardiac surgery involving cardiopulmonary bypass is a complex procedure that results in significant changes to blood coagulation, fibrinolytic biochemistry, platelet number and function, and the vasculature. These are due to pharmacological agents which are administered, haemodilution and contact of the blood with artificial surfaces. Consequently there are significant risks of thrombosis and haemorrhage associated with this procedure. The research presented in this thesis utilises in vitro, in vivo, and a novel ex vivo model to investigate the nature of the haemostatic defect induced by cardiopulmonary bypass. The components studied include the drugs heparin, protamine sulphate, and aprotinin, different types of bypass circuitry (including heparin bonded circuits) and procedures such as acute normovolaemic haemodilution. Patient variables, such as Factor V Leiden, are also studied. Each of these components is assessed for the effects on a number of laboratory measures of haemostasis including activated partial thromboplastin time, prothrombin time, activated protein C ratio, antithrombin concentration, heparin concentration, thrombin-antithrombin complex formation, prothrombin fragment 1+2 formation, markers of platelet surface activation and secretion, activated clotting time, haemoglobin concentration and coagulation factor assays.
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Vassalos, Tony. "End organ effects of paediatric cardiopulmonary bypass." Thesis, University of Glasgow, 2011. http://theses.gla.ac.uk/2385/.
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Despite the scientific, technological and surgical improvements of the past 50 years organ dysfunction following elective paediatric cardiac surgery utilising cardiopulmonary bypass continues to account for increased complications, often leading to a protracted course in hospital with a longer stay in intensive care and the potential for irreversible organ damage long term. Furthermore, paediatric cardiac surgeons are routinely undertaking more complex operations with a shift from palliation to early correction. This has resulted in younger children being subjected to longer periods on the bypass machine with increased effects on vital organs. This thesis describes two clinical studies designed to further assess and characterise peri-operative cardiac, renal and pulmonary function in children undergoing elective cardiac repair at a tertiary referral centre in Scotland, UK. In the first instance a prospective, observational study was undertaken in forty-five children to examine the use of tissue Doppler imaging in the assessment of peri-operative cardiac function, its relationship to myocardial injury and clinical outcome. Tissue Doppler parameters were obtained using a Vivid 7 ultrasound scanner with a 7-MHz probe pre-operatively, on admission to paediatric intensive care and on day one. Myocardial injury was assessed using Troponin-I on the first post-operative day by a commercially available chemiluminescent immunoassay. In twenty children within this group peri-operative renal function was also investigated using standard estimates of glomerular filtration rate, namely creatinine clearance measured by the kinetic Jaffe method during the first and second twelve hour post-operative periods, in comparison to serum creatinine and the novel biomarker cystatin C. Routine plasma retained pre-operatively and on days 0, 1, 2 and 3 post-operatively was used to measure serum cystatin C and creatinine using a particle-enhanced nephelometric immunoassay and the Roche Creatinine Plus enzymatic assay respectively. The association between cystatin C and recorded perfusion parameters including bypass duration, pump flow, haematocrit, oxygen delivery and Troponin-I was investigated. Peri-operative pulmonary function was evaluated through a phase IV, randomised, double-blind, placebo controlled trial. In total, twenty four children were randomised to receive oral sildenafil or equivalent volume placebo four times the day before surgery. Blood samples were collected peri-operatively to measure serum cyclic guanosine monophosphate with a commercially available competitive enzyme immunoassay. Haemodynamic data and echocardiography were acquired at two and twenty four hours post-operatively including pulmonary vascular resistance index and bi-ventricular contractility. Post-operative oxygenation was also determined at the same time by oxygen delivery and oxygenation index. In Chapter 2, peri-operative cardiac function as assessed by tissue Doppler imaging was examined. The results of this study demonstrated that pre-operatively, bi-ventricular systolic function in the study group was reduced compared with normal controls, displaying a significant step-wise decrease with increasing complexity of lesion. This picture persisted post-operatively predominantly in the right ventricle and was significantly associated with the extent of myocardial injury. Impaired peri-operative left ventricular function correlated with clinical outcomes. In Chapter 3, peri-operative renal function as assessed by cystatin C and its association with parameters of perfusion was examined. The results of this study demonstrated that in comparison to serum creatinine, cystatin C had a superior correlation with glomerular filtration rate in the early post-operative period. An elevated level of this biomarker was significantly associated with bypass duration, minimum pump flow and post-operative myocardial injury. Haematocrit was not directly linked to renal dysfunction in this study although evidence of a critical dysoxic threshold within the kidney was suggested indirectly through oxygen delivery calculations. In Chapter 4, peri-operative pulmonary function and vascular reactivity in association with the pre-operative administration of oral sildenafil (0.5mg/kg, six hourly) was examined. The results of this trial demonstrated that compared to placebo, pre-operative sildenafil resulted in modest elevations of serum cyclic guanosine monophosphate, limited effects on pulmonary vascular resistance index, significant reductions in peri-operative bi-ventricular contractility, significant reductions in post-operative oxygen delivery and a trend for increasing ventilatory support. In summary, the current thesis has demonstrated that in children undergoing corrective cardiac surgery peri-operative bi-ventricular function can be accurately assessed by tissue Doppler imaging which to date has had limited use in this patient group. With regards to renal function, cystatin C was shown to be a better estimate of glomerular filtration rate and a more sensitive marker of early renal dysfunction in children after surgery. Furthermore, cystatin C identified a transient post-operative renal impairment, the magnitude of which was associated with duration of bypass, pump flow and myocardial injury. In relation to pulmonary function, this research identified that pre-operative administration of oral sildenafil to children undergoing cardiac surgery produced limited effects on pulmonary vascular resistance but was associated with reduced ventricular contractility and post-operative oxygenation raising significant concerns over its routine clinical use.
4
Baig, Kamran. "Effects of complement factor 1 inhibitor on cardiopulmonary function in neonatal cardiopulmonary bypass." Thesis, Imperial College London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.497651.
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Svenmarker, Staffan. "Heparin coating and cardiotomy suction in cardiopulmonary bypass." Doctoral thesis, Umeå : Univ, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-134.
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Jones, J. M. "β2 adrenergic receptor gene therapy during cardiopulmonary bypass." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.605686.
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Salameh, Aida, Stefan Dhein, Ingo Dähnert, and Norbert Klein. "Neuroprotective strategies during cardiac surgery with cardiopulmonary bypass." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-215752.
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Aortocoronary bypass or valve surgery usually require cardiac arrest using cardioplegic solutions. Although, in principle, in a number of cases beating heart surgery (so-called off-pump technique) is possible, aortic or valve surgery or correction of congenital heart diseases mostly require cardiopulmonary arrest. During this condition, the heart-lung machine also named cardiopulmonary bypass (CPB) has to take over the circulation. It is noteworthy that the invention of a machine bypassing the heart and lungs enabled complex cardiac operations, but possible negative effects of the CPB on other organs, especially the brain, cannot be neglected. Thus, neuroprotection during CPB is still a matter of great interest. In this review, we will describe the impact of CPB on the brain and focus on pharmacological and non-pharmacological strategies to protect the brain.
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Booker, Peter Driscoll. "Gut mucosal perfusion in infants undergoing hypothermic cardiopulmonary bypass." Thesis, University of Liverpool, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250543.
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Parratt, Rachel Nalini. "Monocyte activation of coagulation by cardiopulmonary bypass CPB circuits." Thesis, Imperial College London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312851.
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Pallares, Luiz Carlos Marques. "Oxygen transport in cardiopulmonary bypass induced acute lung injury." Thesis, Imperial College London, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307379.
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Collins, J. D. "A study of the liver following cardiopulmonary bypass surgery." Thesis, University of Newcastle Upon Tyne, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.241404.
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Allen, M. L. "Monocytes and their role in inflammation following cardiopulmonary bypass." Thesis, University College London (University of London), 2004. http://discovery.ucl.ac.uk/1446565/.
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Over the last decade there have been dramatic improvements in paediatric cardiac surgery and the outcome for children with congenital heart disease. Whilst the majority recover promptly from surgery, a small unpredictable group of children have persistant requirements for ventilatory and intensive care support. For these children sepsis and systemic inflammatory response syndrome (SIRS) appears to be a major causes of morbidity and mortality. Antigens of the major histocompatibility complex type II (MHC Class II) are decreased on circulating monocytes of many critically ill patients. Persistently low expression of these antigens has been associated with poor prognosis and increased susceptibility to infection. The work presented here examines the hypothesis that "monocyte deactivation", as indicated by reduced MHC Class II expression and decreased whole blood secretion of pro-inflammatory cytokines in response to lipopolysaccharide (LPS), is a factor in the development of sepsis/SIRS following cardiopulmonary bypass. Using flow cytometry, confocal microscopy, enzyme -linked immunosorbant assays, ex vivo whole blood stimulation, and real time-polymerase chain reaction it has been shown that (1) monocyte surface expression of MHC Class II falls following cardiac surgery involving CPB; (2) this reduction in surface expression is paralleled by a reduction in intracelleular MHC Class II stores, and increased transcription of MHC Class II related genes; (3) bypass results in the early and simultaneous rise in both pro-and anti-inflammatory cytokines; (4) whole blood drawn from patients following CPB is profoundly hyporesponsive to LPS stimulation; (5) whole blood hypo-responsiveness precedes the rise in circulating cytokine and that (6) the inflammatory response and morbidity following CPB may be influenced by the presence of cytokine polymorphisms. The results shown here strongly suggest that monocyte MHC Class II surface expression is an excellent diagnostic tool for the identification of the subgroup of children most likely to develop post-operative complications. By identifying this subgroup of children immunomodulative therapy can be appropriately targeted to restore homeostasis and improve outcome.
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Velissaris, Theodore. "Splanchnic injury during coronary surgery with and without cardiopulmonary bypass." Thesis, University of Southampton, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439379.
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Narayan, Pradeep. "Cardiopulmonary bypass against Ischaemic arrest : a prospective randomised study (CAIAS)." Thesis, University of Bristol, 2013. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.633453.
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Deakin, C. D. S. "Analysis of thermal changes in patients during hypothermic cardiopulmonary bypass." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.598464.
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Evans, Betsy Jane. "Investigation of Leucocyte Trafficking inti Skin Blisters During Cardiopulmonary Bypass." Thesis, Imperial College London, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.519603.
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Flannery, Fionnula Rose. "Neuropsychological outcomes in older adults after surgery with cardiopulmonary bypass." Thesis, University of Sussex, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432425.
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Kuo, James Hang Ung. "Blood cell trauma and renal pathophysiology associated with cardiopulmonary bypass." Thesis, University of Newcastle Upon Tyne, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246088.
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Rice, Cynthia K. "Design of a patient monitoring system for cardiopulmonary bypass surgery." Thesis, Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/50081.
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A patient monitoring system for cardiopulmonary bypass surgery has been developed. This
monitoring system uses a SWAN 286-10 computer (fully IBM PC/AT compatible) and a
DT280l-A Input/Output board to monitor seven surgical parameters. This system monitors six
temperatures, the hemoglobin content, the arterial oxygen saturation, the venous oxygen saturation,
the oxygen consumption, and the blood flow rate through the cardiopulmonary bypass circuit.
Additionally, there are three individual timers available. Details and the evaluation of the hardware
and software design of this monitoring system are presented. Also, recommendations for clinical
use are discussed.Master of Science
incomplete_metadata
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Koning, Nick Julius. "Protection of the microcirculation during cardiac surgery with cardiopulmonary bypass." Thesis, Angers, 2017. http://www.theses.fr/2017ANGE0073/document.
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La chirurgie cardiaque sous circulation extra-corporelle conduit à une altération de la perfusion de la microcirculation, qui peut contribuer de façon importante à la dysfonction d’organe postopératoire. Cette thèse rassemble des études cliniques et animales, dont le but était d’investiguer les mécanismes expliquant la dysfonction microcirculatoire en chirurgie cardiaque sous circulation extra-corporelle. En outre nous avons eu pour but d’évaluer deux stratégies thérapeutiques pour la préservation de la perfusion microcirculatoire au cours de la circulation extracorporelle : l’utilisation d’un flux pulsé comparativement à un flux non pulsé conventionnel durant la circulation extra-corporelle, et le traitement par imatinib dans le but de réduire la fuite vasculaire en inhibant la dysfonction de la barrière endothéliale. La thèse actuelle a démontré que la perfusion microcirculatoire est altérée durant et après la chirurgie cardiaque, et que ceci peut être attribué principalement à la dysfonction inflammatoire de la barrière endothéliale et à la fuite vasculaire conséquente. L’hémodilution concomitante en chirurgie cardiaque sous circulation extra-corporelle peut s’ajouter et contribuer également à la réduction de la perfusion microcirculatoire et de l’oxygénation. Nous avons montré que l’utilisation d’un flux pulsé durant la circulation extracorporelle améliore la perfusion microcirculatoire en postopératoire comparativement à un flux non-pulsé. Le traitement par imatinib a réduit la dysfonction de la barrière endothéliale et la fuite vasculaire dans notre modèle de circulation extracorporelle sur le rat et a permis de préserver la perfusion microcirculatoire et l’oxygénation durant et après la circulation extra-corporelle. En outre, le traitement par imatinib a permis de diminuer les marqueurs de souffrance rénale, pulmonaire et digestive après circulation extra-corporelle. A partir de nos résultats, la réduction de la fuite vasculaire et l’utilisation d’un flux pulsé durant la circulation extra-corporelle sont des interventions prometteuses pour la prévention des complications postopératoires chez les patients à risque de défaillance d’organe au décours de la chirurgie cardiaque sous circulation extra-corporelleCardiac surgery with cardiopulmonary bypass leads to impaired perfusion of the microcirculation, which may be an important contributor to postoperative organ dysfunction. This thesis combines clinical and animal studies that aimed to investigate the mechanisms underlying microcirculatory dysfunction in cardiac surgery with cardiopulmonary bypass. Moreover, we aimed to evaluate two treatments strategies for preservation of microcirculatory perfusion during cardiopulmonary bypass : the use of pulsatile flow as compared to the conventional non pulsatile flow during cardiopulmonary bypass and treatment with imatinib in order to reduce vascular leakage by inhibiting endothelial barrier dysfunction.The current thesis has demonstrated that microcirculatory perfusion is impaired during and after cardiac surgery, and this can be attributed mainly to inflammatory endothelial barrier dysfunction and consequent vascular leakage. Concomitant hemodilution may additionally contribute to reduced microvascular perfusion and oxygenation in on-pumpcardiac surgery. We showed that the use of pulsatile flow during cardiopulmonary bypass improves postoperative microvascular perfusion as compared to non pulsatile flow. Imatinib treatment reduced endothelial barrier dysfunction and vascular leakage in our rat model for cardiopulmonary bypass and resulted in preservation of microcirculatory perfusion andoxygenation during and after extracorporeal circulation.Moreover, imatinib treatment resulted in reduced markers ofrenal, pulmonary and intestinal injury after cardiopulmonary bypass. Based on our findings, reduction of vascular leakage and use of pulsatile flow during cardiopulmonary bypass are promising interventions for the prevention of postoperative complications in patients at risk for organ failure following cardiac surgery with cardiopulmonary bypass
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Ray, Michael John. "Causes and prevention of excessive bleeding after cardiopulmonary bypass surgery." Thesis, Queensland University of Technology, 1997.
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Rajakaruna, Chanaka. "Splanchnic organ function and glucose metabolism during coronary artery bypass surgery with or without cardiopulmonary bypass." Thesis, University of Bristol, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492604.
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Methods: Patients were randomised to off-pump coronary artery bypass grafting (OPCAB) or conventional coronary artery bypass grafting with cardiopulmonary bypass (CABG-CPB). Small intestine function was assessed by differential four sugars (0=methyl-D-glucose, D-xylose, L-rhamnose, and Lactulose) permeability and absorption tests before surgery, at day 1 and day 5 post-surgery. Liver function was assessed before and at the end of surgery by monoethylglycinexyhdide (MEGX)/Iidocaine ratios after injection of 1 mg/kg bolus of lidocaine and by serial measurements of transaminases (AST and ALT), bilirubin, and alkaline phosphatase (ALP).
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Ofoegbu, Chimu K. P. "Outcomes of "off-pump" coronary artery bypass grafting in a developing country : advantages over coronary artery bypass grafting on cardiopulmonary bypass." Master's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/11432.
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Includes abstract.Includes bibliographic references (leaves 53-62).
Off-pump coronary artery bypass grafting (OPCAB) was developed to avoid the deleterious effects of CPB. Current literature reveals some peri-operative advantages of OPCAB, with few studies detailing these in Africa. We review our institutional experience with both approaches in higher risk patients to determine pre-operative characteristics, short and mid-term outcomes in a developing country.
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Figueras, Cecile Amanda. "The effects of geometric changes on flow patterns in anastomotic grafts." Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/16751.
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Maquelin, Kyra Nicole. "Platelet activation and microparticles in the pericardial cavity during cardiopulmonary bypass." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2003. http://dare.uva.nl/document/70014.
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Li, Jia. "Oxygen consumption and oxygen delivery in children after cardiopulmonary bypass surgery." Thesis, Imperial College London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406548.
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Tovedal, Thomas. "Cerebral perfusion during cardiopulmonary bypass with special reference to blood flow." Doctoral thesis, Uppsala universitet, Anestesiologi och intensivvård, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-248686.
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Cardiopulmonary bypass (CPB) is an important method that enables open heart surgery. There is a risk of neurological complications, and efforts to minimize those include optimization of the cerebral perfusion during CPB. This thesis focuses on such optimization of flow conditions in case of obstructed venous drainage, carotid stenosis and during selective antegrade cerebral perfusion (SACP). In a pig model of impaired venous drainage from the superior vena cava (SVC), stepwise obstruction increased the central venous pressure (CVP) and caused impaired oxygenation. Cerebral micro-dialysis revealed ischemic responses in some but not all of the pigs. Further experiments, using the same model, aimed to restore cerebral perfusion pressure (CPP) reduced by 75% superior venous obstruction. Both vasopressor treatment and increased venous drainage were effective in normalizing the CPP and improving the cerebral oxygenation. The intracranial pressure was elevated in the vasopressor group, but no signs of brain damage were observed. The arterial flow during CPB can be altered between pulsatile and non-pulsatile profiles. Switching between these modes was performed during CPB in 20 patients with or without carotid stenosis. The effects on cerebral oxygenation and mean arterial pressure (MAP) were examined. The MAP was significantly lowered by pulsatile flow, but the flow profile did not affect the cerebral oxygenation. No differences were seen between patients with or without carotid stenosis. SACP is used to ensure the cerebral perfusion during deep hypothermic circulatory arrest (HCA). The cerebral blood flow (CBF) was examined using positron-emission tomography (PET) technique in 8 pigs divided into HCA and HCA+SACP groups. The CBF was downregulated by 70% to 0.10 ml/cm3/min by 20°C hypothermia. A pump flow of 6 ml/kg/min preserved the CBF level without signs of cerebral desaturation. The fluorodeoxyglucose (FDG) uptake after re-warming to 37°C was similar after SACP compared with HCA alone. In conclusion, experimental SVC obstruction may impair the cerebral perfusion. Vasopressors can restore the CPP during SVC obstruction and improve cerebral oxygenation. In patients, pulsatile flow can lower the MAP in absence of effects on the cerebral oxygenation. During experimental HCA, SACP at 6 ml/kg/min can preserve the CBF at 0.10 ml/cm3/min.
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Gourlay, T. "Controlled pulsatile architecture in cardiopulmonary bypass : in-vitro and clinical studies." Thesis, University of Strathclyde, 1997. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21361.
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The clinical effects of pulsatile cardiopulmonary bypass (CPB) has been the focus of study for some time. In an effort to establish which aspects of pulse architecture are responsible for these clinical benefits, it is necessary to describe, in hydrodynamic terms, the pulse flow and pressure patterns, or architecture. A model of the human systemic circulation was designed and constructed for this purpose and two pulsatile perfusion pumps were studied, one was a roller pump, the other a new ventricular pump. It was anticipated that the ventricular mechanism would offer a higher degree of control of pulse architecture. Both systems were found to offer a high degree of output control and as anticipated the ventricular system offered better control of output architecture than the roller pump. In all aspects of the study of output architecture the ventricular pump was more powerful than the roller pump. However it was found that the ventricular pump was associated with the gen eration of significantly more microbubbles and this precluded its use in the clinical study. Having established four different architectures with the roller mechanism, one of which was non-pulsatile, the clinical study proceeded with this pump alone. The pulsatile groups as a whole, were found to offer metabolic and haemodynamic advantages over the non-pulsatile group. There were no differences between the various groups in terms of measures of organ damage during CPB. The non-pulsatile flow group had the highest level of nitric oxide activity, which appeared not to be related to any haemodynamic effect, but to a reperfusion or hypo-perfusion phenomenon. The differences between the pulsatile flow groups were in general not significant. The difficulty in achieving statistical significance between the pulsatile flow groups was thought to be related to the very small differences between the groups in terms of the magnitude of the parameters which contribute to the architecture . The methodology developed in this study can help to establish which aspects of pulse architecture are of importance during clinical CPB. This may not be possible however until the microbubble generation problems associated with the use of the ventricular mechanism has been solved.
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Whitbourne, Peta Gaye. "Changes in the clotting viscoelasticity caused by cardiopulmonary bypass (CPB) surgery." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/50547.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1998.Includes bibliographical references (leaves 63-66).
One to three percent of the Open Heart Surgery procedures have abnormal bleeding due to acquired platelet dysfunction. Standard clotting tests to determine the cause of bleeding usually take between 25 and 60 minutes to get results. This time frame is not useful for deciding what type of treatment to give to a patient. More importantly, the standard clotting tests is they cannot determine platelet function. The Thrombo-Visco Elastogram (TVE) is a new test that provides results in less than 15 minutes and has the potential to evaluate platelet function. In this study, we used the TVE test to assess viscoelasticity of clotting blood from patients before and after CPB. For each patient and condition, we tested the blood alone and after incubation with a saturation concentration of ReoProTM, a glycoprotein Ilb/Illa inhibitor. The major findings of this study are: 1) The TVE device is capable of determining with accuracy quantitative changes in blood viscoelasticity during clotting; 2) The TVE-derived coagulation parameters maximum elastic modulus (Emax), maximum rate of change of elastic modulus (E'max), maximum viscosity ([eta]max), and maximum rate of change of viscosity ([eta]'max) and the coagulation parameters prothrombin time (PT), platelet count, fibrinogen concentration and hematocrit are all affected by CPB; 3) The TVE-derived parameters were all substantially affected by incubation of the blood with the platelet GP inhibitor suggesting that these parameters are exquisitely sensitive to platelet function; and 4) In ReoProTM-free blood samples, values of E'max for all patients, before and after CPB, could be predicted as a function of platelet count, fibrinogen concentration and hematocrit. We concluded that the TVE/ReoProTM assay has the potential to assess the contribution of platelet function and soluble components to coagulation in a quantitative, reproducible and practical manner.
by Peta Gaye Sonya Whitbourne.
S.M.
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Wanikiat, Payong. "Inhibition of neutrophil activation : effects in reperfusion injury and cardiopulmonary bypass." Thesis, University of Edinburgh, 2000. http://hdl.handle.net/1842/23245.
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The aims of this thesis were: 1) to establish the role of nitric oxide (NO) and cyclic GMP in neutrophil chemotaxis and superoxide anion generation (SAG), 2) to investigate the effects of a novel NO donor GEA 3162, the A2A receptor agonist 2-HE-NECA, and the PGI2 analogue cicaprost on neutrophil accumulation and myocardial injury in vivo, in a rat model of MI-R, and 3) to identify the role of neutrophil activation in the formation of stable platelet aggregates and whether heparin, which is used systematically to anticoagulate for CPB, contributed to platelet dysfunction during CPB by interfering with neutrophil-platelet interactions. Effects of heparin in vitro, on neutrophil SAG and myeloperoxidase release were also determined. The mechanisms responsible for chemotaxis and neutrophil activation are not fully understood. Selective inhibitors of the NO and cyclic GMP pathways have been used to elucidate their roles in the activation and inhibition of human neutrophils. In addition, the ability of NO donors to inhibit neutrophil chemotaxis was compared with their ability to increase neutrophil nitrate/nitrate and cyclic GMP levels. The results confirm that neutrophil activation results from the stimulation of several signal transduction systems. It appears that chemotaxis can occur via a NO-dependent as well as NO-independent pathway. Similar pathways appear to operate in SAG. The results also suggested that the small concentrations of NO and cyclic GMP induced by fMLP activated neutrophils while large concentrations of NO and cyclic GMP are inhibitory. The effects of GEA 3162, 2-HE-NECA, and cicaprost on neutrophil accumulation and myocardial injury in a rat model of MI-R were investigated. Myocardial ischaemia was induced by occlusion of the left main coronary artery (45 min) and then reperfused (120 min). Drugs or saline vehicle were infused intravenously for 130 min beginning 10 min before reperfusion. Neutrophil accumulation in the area at risk and normal area was assessed by myeloperoxidase assay.
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Raedschelders, Koen. "A clinical appraisal of propofol-mediated, antioxidant-based cardioprotection during coronary artery bypass grafting with cardiopulmonary bypass." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/33736.
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Coronary artery disease is the leading cause of death in North America. The invasiveness of its treatment depends on its severity; less severe disease can be treated pharmacologically or surgically without significantly different outcomes, but coronary artery bypass grafting (CABG) clearly reduces mortality among medium- and high-risk patients compared to percutaneous and non-surgical intervention.
Although the majority of patients undergoing surgical revascularization emerge without severe postoperative complications, a significant portion of patients encounter a postoperative complication known as low cardiac output syndrome which can quadruple the overall mortality rate for CABG. Intraoperative ischemia reperfusion injury is a major factor in the development of low cardiac output syndrome; so effective intraoperative myocardial protection is central to reducing its incidence, and represents an opportunity to considerably improve patient outcomes.
The introductory chapter of this thesis describes the origin and role of reactive oxygen species (ROS) in myocardial ischemia-reperfusion injury. In addition, it introduces key strategies targeted to reduce ROS-mediated myocardial ischemia-reperfusion injury, highlighting key clinical studies that translated these strategies to reduce the severity of ischemia-reperfusion injury during CABG.
The central hypothesis of the clinical project on which this thesis is based states that propofol reduces the incidence of low cardiac output syndrome subsequent to CABG with CPB by decreasing the magnitude of 15-F₂t-isoprostane generation during ischemia-reperfusion. The second chapter introduces propofol, and will review previous studies that explore its cardioprotective potential.
The experimental section of this thesis describes the development of a quantitative technique for propofol analysis in whole blood, and its application in a dose finding study that define the parameters for achieving experimentally relevant concentrations of propofol during cardiopulmonary bypass. These two studies were fundamental to the development of a clinical study evaluating ROS generation and the incidence low cardiac output syndrome in patients undergoing CABG surgery.
Preliminary results that address the central hypothesis are subsequently presented, along with an alternative proposed mechanism for propofol-mediated cardioprotection. This thesis will conclude with a summary of findings and a description of several future studies aimed at testing, generating, and evaluating new hypotheses.
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Taggart, David Paul. "The effects of a platelet activating factor antagonist on the respiratory, myocardial and cerebral consequences of cardiopulmonary bypass and further observations on cardiac surgery without cardiopulmonary bypass." Thesis, University of Strathclyde, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248531.
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Annapoorna, Mary. "Cardiopulmonary predicators of dysfunctional ventilator weaning response after coronary artery bypass Graft." View the abstract Download the full-text PDF version, 2007. http://etd.utmem.edu/ABSTRACTS/2007-017-annapoorna-index.html.
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Thesis (Ph.D.)--University of Tennessee Health Science Center, 2007.Title from title page screen (viewed on July 18, 2008). Research advisor: Dr. Carol Lynn Thompson, PhD. Document formatted into pages (xiv,151 p. : ill.). Vita. Abstract. Includes bibliographical references (p. 132-144).
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Warren, Oliver J. "Defining the role of leukocyte depleting filters within the cardiopulmonary bypass circuit." Thesis, Imperial College London, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.506052.
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Svoren, E. M. "Genetic regulation of the host response to cardiac surgery and cardiopulmonary bypass." Thesis, Queen Mary, University of London, 2017. http://qmro.qmul.ac.uk/xmlui/handle/123456789/31868.
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There is significant variation between individual patients in the magnitude and pattern of their systemic response to cardiac surgery. Poor outcomes in these patients have been associated with a dysfunctional host response. This thesis seeks to define such variability at the level of gene expression by sequential analysis of transcription before and after surgery for a low risk group of patients undergoing elective cardiac surgery and cardiopulmonary bypass (CPB) patients using expression microarray profiling. To that aim, we analysed sequential global gene expression patterns in circulating peripheral blood leukocytes. We also investigated the role of DNA sequence variation in modulating the observed changes in gene expression. This approach allowed us to identify important genetic modulators and novel biological pathways and gain new insights into the mechanisms that regulate the host response to surgery.
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Raymond, Paul Douglas. "Haemostatic activation and its relationship to neuropsychological changes following cardiopulmonary bypass surgery." Thesis, Queensland University of Technology, 2006. https://eprints.qut.edu.au/16405/1/Paul_Raymond_Thesis.pdf.
Full textAbstract:
Neuropsychological impairment following cardiopulmonary bypass (CPB) remains a serious consequence of otherwise successful surgery. The incidence of neuropsychological decline is poorly understood due to varied measurement intervals, and perhaps more importantly the use of unreliable detection and classification methods. The reported incidence varies considerably, ranging anywhere from 30% to 90% of subjects. While the nature of this impairment has not been fully elucidated, recent evidence suggests that microembolism during surgery may be the principal causative agent of postoperative cerebral dysfunction. The work described in this thesis investigates one possible source of microembolism leading to postoperative decline, namely thromboembolism arising from excessive activation of the haemostatic mechanism. Crucial to the accurate detection of significant decline in individual patients, this work also focuses on the development and use of meaningful criteria to be used when describing change in neuropsychological performance measures.
The strong haemostatic activation during CPB is controlled by heparin anticoagulation. The clinical performance of the Hepcon heparin-monitoring instrument was compared to the activated clotting time (ACT), which is used in most cardiac centres. An analysis of samples from 42 elective coronary artery bypass grafting (CABG) patients shows that the ACT does not detect the significant decline in heparin concentration seen upon connection to CPB, in comparison to the Hepcon. The Hepcon appears to be in satisfactory agreement with laboratory anti-Xa analysis of heparin concentration, with the mean difference for the Hepcon at -0.46 U/ml, and the limits of agreement +/- 1.12 U/ml. Further analysis shows that that for 95% of cases, the Hepcon will give values that are between 0.53 and 1.27 times the value for anti-Xa.
The loss of relationship between ACT and heparin concentration was further investigated by converting ACT values to heparin concentration. The results provide data on the degree of prolongation in ACT times brought about by factors associated with CPB. A methodology is presented by which users can adjust for the loss of relationship between ACT and heparin. This work also demonstrates that under normal usage of the ACT, the user may obtain values up to 3 times appropriate for the plasma heparin concentration.
The computer-administered neuropsychological testing tool (the MicroCog) was validated using 40 age-matched control subjects. Using a two-week interval, the summary score correlation coefficients ranged from .49 to .84, with all scores demonstrating significant practice effects. Also presented are retest normative data that may be used to determine significant change in a homogeneous sample using both reliable change and regression models of analysis. The performance of four different models of change analysis was then analysed using data from the clinical group. The regression technique of analysis was shown to be the most useful prediction model as it provides correction for both practice effects and regression toward the mean in each individual. A novel statistical rationale is presented for the choice of criteria in the identification of patients that may be defined as overall impaired when using a battery of test scores. When using one-tailed prediction models for decline, the binomial distribution of scores was shown to be a useful descriptive statistic providing an estimate of change due to chance. When applied to a suitable selection of scores that minimise shared variance, a value +/- 20% of test scores used was demonstrated to be a rational cut-off for an individual to be classified as impaired. Using this methodology, 32.7% of patients were identified as significantly deteriorated in neuropsychological test function immediately prior to discharge from hospital. Patient age was shown to be a significant predictor of neuropsychological decline following CPB. No significant relationship was identified between thrombin generation and neuropsychological change scores, however problems with patient recruitment and retention limited the statistical power of this study. An intriguing relationship with heparin concentration was noted that might warrant further investigation.
This work highlights the complex nature of post-bypass neuropsychological dysfunction and the complexities in assessing decline. The regression-based model was shown to be highly useful in the analysis of data from a suitably validated neuropsychological testing tool. The argument that no suitable criterion exists for the identification of patients as overall impaired has been challenged with the development of a rational cut-off based on the likely distribution of change scores across a series. The work presented here confirms the need for standardised testing methods based on sound statistical criteria. This work also highlights the problems associated with current methods for monitoring anticoagulation therapy during bypass surgery. Methodology is presented that allows adjustment of ACT results to account for CPB-induced prolongation of clotting times. Current techniques for heparin monitoring overestimate heparin levels on bypass by up to threefold, which may predispose to subclinical coagulation and increased delivery of protamine.
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Raymond, Paul Douglas. "Haemostatic activation and its relationship to neuropsychological changes following cardiopulmonary bypass surgery." Queensland University of Technology, 2006. http://eprints.qut.edu.au/16405/.
Full textAbstract:
Neuropsychological impairment following cardiopulmonary bypass (CPB) remains a serious consequence of otherwise successful surgery. The incidence of neuropsychological decline is poorly understood due to varied measurement intervals, and perhaps more importantly the use of unreliable detection and classification methods. The reported incidence varies considerably, ranging anywhere from 30% to 90% of subjects. While the nature of this impairment has not been fully elucidated, recent evidence suggests that microembolism during surgery may be the principal causative agent of postoperative cerebral dysfunction. The work described in this thesis investigates one possible source of microembolism leading to postoperative decline, namely thromboembolism arising from excessive activation of the haemostatic mechanism. Crucial to the accurate detection of significant decline in individual patients, this work also focuses on the development and use of meaningful criteria to be used when describing change in neuropsychological performance measures.
The strong haemostatic activation during CPB is controlled by heparin anticoagulation. The clinical performance of the Hepcon heparin-monitoring instrument was compared to the activated clotting time (ACT), which is used in most cardiac centres. An analysis of samples from 42 elective coronary artery bypass grafting (CABG) patients shows that the ACT does not detect the significant decline in heparin concentration seen upon connection to CPB, in comparison to the Hepcon. The Hepcon appears to be in satisfactory agreement with laboratory anti-Xa analysis of heparin concentration, with the mean difference for the Hepcon at -0.46 U/ml, and the limits of agreement +/- 1.12 U/ml. Further analysis shows that that for 95% of cases, the Hepcon will give values that are between 0.53 and 1.27 times the value for anti-Xa.
The loss of relationship between ACT and heparin concentration was further investigated by converting ACT values to heparin concentration. The results provide data on the degree of prolongation in ACT times brought about by factors associated with CPB. A methodology is presented by which users can adjust for the loss of relationship between ACT and heparin. This work also demonstrates that under normal usage of the ACT, the user may obtain values up to 3 times appropriate for the plasma heparin concentration.
The computer-administered neuropsychological testing tool (the MicroCog) was validated using 40 age-matched control subjects. Using a two-week interval, the summary score correlation coefficients ranged from .49 to .84, with all scores demonstrating significant practice effects. Also presented are retest normative data that may be used to determine significant change in a homogeneous sample using both reliable change and regression models of analysis. The performance of four different models of change analysis was then analysed using data from the clinical group. The regression technique of analysis was shown to be the most useful prediction model as it provides correction for both practice effects and regression toward the mean in each individual. A novel statistical rationale is presented for the choice of criteria in the identification of patients that may be defined as overall impaired when using a battery of test scores. When using one-tailed prediction models for decline, the binomial distribution of scores was shown to be a useful descriptive statistic providing an estimate of change due to chance. When applied to a suitable selection of scores that minimise shared variance, a value +/- 20% of test scores used was demonstrated to be a rational cut-off for an individual to be classified as impaired. Using this methodology, 32.7% of patients were identified as significantly deteriorated in neuropsychological test function immediately prior to discharge from hospital. Patient age was shown to be a significant predictor of neuropsychological decline following CPB. No significant relationship was identified between thrombin generation and neuropsychological change scores, however problems with patient recruitment and retention limited the statistical power of this study. An intriguing relationship with heparin concentration was noted that might warrant further investigation.
This work highlights the complex nature of post-bypass neuropsychological dysfunction and the complexities in assessing decline. The regression-based model was shown to be highly useful in the analysis of data from a suitably validated neuropsychological testing tool. The argument that no suitable criterion exists for the identification of patients as overall impaired has been challenged with the development of a rational cut-off based on the likely distribution of change scores across a series. The work presented here confirms the need for standardised testing methods based on sound statistical criteria. This work also highlights the problems associated with current methods for monitoring anticoagulation therapy during bypass surgery. Methodology is presented that allows adjustment of ACT results to account for CPB-induced prolongation of clotting times. Current techniques for heparin monitoring overestimate heparin levels on bypass by up to threefold, which may predispose to subclinical coagulation and increased delivery of protamine.
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Varghese, David. "Perioperative organ dysfunction in patients undergoing coronary artery bypass grafting either with cardiopulmonary bypass and cardioplegic arrest or without." Thesis, University of Southampton, 2010. https://eprints.soton.ac.uk/364928/.
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Rimpiläinen, R. (Riikka). "Minimized cardiopulmonary bypass in extracorporeal circulation:a clinical and experimental comparison with conventional techniques." Doctoral thesis, Oulun yliopisto, 2011. http://urn.fi/urn:isbn:9789514294310.
Full textAbstract:
Abstract Cardiac surgery with cardiopulmonary bypass (CPB) results in hemodilution, systemic inflammatory response, activation of coagulation and fibrinolysis, and microembolisation, which may all contribute to postoperative organ dysfunction. As an attempt to attenuate these side effects, the use of minimized cardiopulmonary bypass (MCPB) systems has increased. Compared to conventional CPB (CCPB), they are characterized with reduced artificial surface area and blood-air interface. The goal of these alterations has been to reduce systemic inflammation, preserve coagulation function and minimize the need for blood tranfusions. This study was aimed at determining whether or not MCPB attenuates the adverse effects of CPB. In study I, the safety, feasibility and effect on transfusion requirements of MCPB was investigated in unselected coronary artery bypass surgery (CABG) patients. In studies II and III, the incidence of retinal microembolism after CABG and aortic valve replacement (AVR) surgery with MCPB was compared to that of CCPB by means of fluorescein angiography. Furthermore, in studies II and III, the effect of MCPB on systemic inflammation, coagulation, endothelial activation and injury, as well as on platelet activity, was compared to those of CCPB. In study IV, the effect of MCPB on intestinal mucosal damage following CPB was compared to CCPB in a porcine model of prolonged CPB. MCPB appeared as safe and feasible as CCPB in unselected CABG patients (Study I). MCPB was associated with decreased retinal microembolism compared to CCPB in CABG patients (Study II). Conversely, the difference in retinal microembolism in AVR patients was not statistically significant (Study III). MCPB was associated with a decrease in neutrophil activation in CABG and AVR patients as compared to CCPB. However, there were no differences in coagulation, endothelial activation and injury, or in platelet activity (Studies II, III). There were no differences in markers of intestinal mucosal damage between MCPB and CCPB following prolonged CPB in the experimental model (Study IV). The results of this study suggest that MCPB may be used safely with CABG patients, with beneficial effects on hematocrit, and attenuated neutrophil activation. In CABG patients, MCPB is associated with reduced retinal microembolism, suggesting a decreased embolic load to the brain. The clinical feasibility of MCBP requires further technical evolution in the management of valve surgery. The results of the animal model support previous concerns regarding intestinal mucosal damage during CPBTiivistelmä Sydänkeuhkokoneen käyttö aiheuttaa elimistössä hemodiluution, yleistyneen tulehdusvasteen ja hyytymisjärjestelmän aktivoitumisen sekä mikroembolisaatiota. Ilmiöt ovat yleensä lieviä ja ohimeneviä, mutta voivat johtaa elintoimintahäiriöihin ja pitkittyneeseen toipumiseen sydänleikkauksen jälkeen. Haittojen lievittämiseksi sydänkeuhkokonetta on pyritty kehittämään fysiologisemmaksi. Miniperfuusiolaitteistoissa kiertävän veren kontakti pintamateriaalien ja ilman kanssa jää pienemmäksi ja veren laimenemista tapahtuu vähemmän. Tutkimuksen tavoitteena oli selvittää voidaanko miniperfuusiolla lievittää sydänkeuhkokoneen haittoja. Ensimmäisessä osatyössä selvitettiin miniperfuusion käyttökelpoisuutta ja vaikutusta verensiirtotarpeeseen ohitusleikkauspotilailla valikoimattomassa aineistossa. Toisessa ja kolmannessa osatyössä selvitettiin silmänpohjan mikroembolioiden ilmaantuvuutta miniperfuusion ja perinteisen sydänkeuhkokoneen käytön jälkeen ohitusleikkauspotilailla ja aorttaläppäleikkauspotilailla. Toisessa ja kolmannessa osatyössä selvitettiin lisäksi miniperfuusion vaikutuksia yleistyneen tulehdusvasteen voimakkuuteen, hyytymisjärjestelmään sekä endoteelin aktivaatioon perinteiseen sydänkeuhkokoneeseen verrattuna. Neljännessä osatyössä verrattiin kokeellisessa mallissa miniperfuusion ja perinteisen sydänkeuhkokoneen vaikutuksia suoliston limakalvon eheyteen. Miniperfuusio ilmeni yhtä käyttökelpoiseksi kuin perinteinen sydänkeuhkokone ohitusleikkauspotilaiden hoidossa. Ohitusleikkauspotilailla ilmeni vähemmän silmänpohjan mikroembolioita miniperfuusion jälkeen, mutta aorttaläppäleikkauspotilailla ero ei ollut tilastollisesti merkitsevä. Miniperfuusion käyttöön liittyi vähemmän neutrofiilien aktivaatiota. Tekniikoiden välillä ei ilmennyt eroa hyytymisjärjestelmän eikä endoteelin aktivaatiota osoittavissa merkkiaineissa. Sydänkeuhkokoneen käyttö aiheutti saman tasoisen suoliston limakalvon vaurion miniperfuusiolla ja perinteisellä sydänkeuhkokoneella. Tutkimuksen perusteella miniperfuusiotekniikkaa voidaan käyttää turvallisesti ohitusleikkauspotilaiden hoidossa ja sen käyttö vähentää hemodiluutiota ja neutrofiilien aktivaatiota verrattuna perinteiseen sydänkeuhkokoneeseen. Miniperfuusiolla voidaan vähentää sydänkeuhkokoneen käytön aiheuttamaa silmänpohjan mikroembolisaatiota, joka saattaa viitata vähäisempään aivoverenkierron mikroembolisaatioon. Miniperfuusiotekniikoiden tulee edelleen kehittyä hyödyttämään enemmän myös aorttaläppäleikkauspotilaita. Löydökset koskien sydänkeuhkokoneen aiheuttamia suoliston limakalvovaurioita vahvistavat aiempaa olettamusta suoliston haavoittuvuudesta sydänleikkauksen jälkeen
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Hyde, Jonathan A. J. "The effect of flow generation technique during cardiopulmonary bypass on remote organ injury." Thesis, King's College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268855.
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Funamoto, Masaki. "Green Tea Polyphenol Prevents Diabetic Rats From Acute Kidney Injury After Cardiopulmonary Bypass." Kyoto University, 2018. http://hdl.handle.net/2433/232476.
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Percy, Charles L. "Predicting excess bleeding due to haemostatic failure following cardiac surgery requiring cardiopulmonary bypass." Thesis, Cardiff University, 2015. http://orca.cf.ac.uk/76453/.
Full textAbstract:
Bleeding following cardiac surgery requiring cardiopulmonary bypass (CPB) is associated with increased morbidity. Identification of patients at increased risk of bleeding might allow intervention to prevent bleeding developing. In this thesis, clotting factors, anticoagulants and calibrated automated thrombin generation were investigated as potential methods for identifying such patients. Post-CPB FXIII, fibrinogen and platelet count were significantly lower in those who bleed more than 2 mL/kg/hr for two consecutive hours and in those who bleed in excess of 1 litre at 24 hours. ROC analysis demonstrated these had modest predictive value. Calibrated automated thrombography was unable to identify patients at risk of bleeding. Calibrated automated thrombography was also used to investigate the effects of haemostatic treatment (FFP, rFVIIa, PCC and TFPI inhibition) on thrombin generation in vitro. Blocking the effect of TFPI produced the greatest improvement in thrombin generation. The effect of CPB on platelet phospholipids was investigated using mass spectrometry. Post-CPB the ability to externalise phosphatidylethanolamine and phosphatidylserine was impaired. The ability to externalise and synthesise 12-HETE-PC and 12-HETE-PE in response to both thrombin and collagen post-CPB was also reduced. The effect of these phospholipids on thrombin generation and the ability to identify patients at risk of bleeding was then investigated. Thrombin generation using liposomes containing 12-HETE-PC or 12-HETE was lower in patients who required haemostatic treatment for post-CPB bleeding compared to those who did not. This suggests there are variations between individuals in the way their coagulation factors interact with oxidised phospholipids and that this may influence bleeding. Finally a cell based model of thrombin generation was developed using monocytes as a source of tissue factor and incorporating the observed changes in phospholipids, clotting factors and anticoagulants. This model provides a basis to further investigate the influence of different TF expressing cells on thrombin generation which may affect bleeding.
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Hector, Lauren Rachel. "Patient predisposition and the inflammatory response following cardiopulmonary bypass : the role of haemolysis." Thesis, Imperial College London, 2012. http://hdl.handle.net/10044/1/9505.
Full textAbstract:
Cardiopulmonary bypass (CPB) is necessary for the majority of cardiac surgery however it is often associated with the development of the systemic inflammatory response syndrome (SIRS). In a proportion of patients, SIRS is complicated by acute lung injury (ALI) and the more extreme acute respiratory distress syndrome (ARDS). Despite a reduction in mortality with lung protective ventilation, there are no effective therapies for ALI consequent on snCPB. Acute neutrophilic pulmonary inflammation, dysregulated cytokine response and abnormal iron mobilisation/handling have been implicated in the pathophysiology. However, only a minority of at risk individuals develop ALI indicating a predisposing influence for disease onset. CPB induces a host of pro-inflammatory cytokines and also causing a dysregulation of iron-handling, which have also been implemented in the developed of SIRS. This thesis examines aspects of the iron handling and associated inflammatory response in patients undergoing CBP and investigates the hypothesis that genetic variation in the genes associated with these responses influences patient outcome manifest as SIRS. A cohort of patients (n=199) undergoing CPB were genotyped for biallelic single nucleotide polymorphisms (SNPs) in numerous genes including haptoglobin (HP), HAMP, LTA and IL-6 genes using sequence-specific primer polymerase chain reactions and the genotypes related to clinical outcomes. Statistically significant associations were found between polymorphisms in the homozygous carriage of HP-85AA, IL-6 -174C and IL-6 intron 4 allele G with impaired post-operative oxygenation and increased markers of systemic inflammation (i.e. CRP); and in HAMP +1960G and LTA +249A or LTA +723C with abnormal white cell count. Other associations were found with CD163, HO-1 and HO-2, Light and heavy chain ferritin and hepcidin, these results are detailed within the thesis. The findings from these investigations, suggest that genetic variation in iron handling and cytokine genes are associated with increased risk of adverse outcome following snCPB.These findings support a link between abnormal iron handling and the inflammatory response in ALI ensuing from snCPB and have important implications for future research and clinical practice.
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Igreja, S. "The influence of mannose-binding lectin polymorphisms in children undergoing cardiopulmonary bypass surgery." Thesis, University College London (University of London), 2006. http://discovery.ucl.ac.uk/1445938/.
Full textAbstract:
Genetic factors may influence the outcome from surgery. Mannose-Binding lectin (MBL) is an important factor in innate immune defense. MBL gene polymorphisms result in deficiency of the encoded protein and increase susceptibility to infection. The objective of this study was to investigate the relationship between MBL-2 exon 1 polymorphisms and outcome of children after cardiopulmonary bypass (CPB) surgery. Two hundred and forty four patients were recruited to this study. Patient's MBL-2 genotype was determined and compared with respect to sepsis development, length of stay in intensive care and duration of mechanical ventilation. The exon 1 polymorphisms were more common in the patients with sepsis compared to the non-sepsis group (36% vs. 47%). It was observed a higher proportion of MBL-2 variant alleles in the patients who required prolonged stay compared to the short stay group (38% vs. 51%). Similarly, MBL-2 variant alleles were more common in those who required prolonged ventilation compared to those who required less ventilation (33% vs. 50%). Three was a significant association between MBL-2 genotype and the duration of ventilation (p = 0.033). The data from this study showed that MBL-2 exon 1 polymorphisms may play an important role in the outcome of children undergoing surgery.
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Sheppard, Stuart Vincent. "Leucocyte filtration and cardiac surgery." Thesis, University of Portsmouth, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310490.
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Solberg, Robert Glen. "Extracorporeal Circulation: Effect of Long-Term (24-Hour) Circulation on Blood Components." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/32157.
Full textAbstract:
Extracorporeal circulation damages blood and causes harmful side effects such as stroke and/or systemic inflammatory response in patients. Reactions of blood components to extracorporeal circulation include complement and inflammatory reactions, coagulation and thrombogenesis, frank hemolysis, and platelet activation and adhesion to the extracorporeal circuit. Non-physiologic pressure and flow produced by blood pumps contribute to blood injury. Two pump types, roller and centrifugal, are used for maintaining flow, with various models available from different manufacturers. This study compared the effects of these two pumps in identical, isolated, artificial circuits to a non-pumped control for a period of 24 hours on heparinized porcine blood. Hematology parameters were used to evaluate blood damage. Mean corpuscular volume, mean corpuscular hemoglobin, white blood cell count, platelet count, and mean platelet volume were affected by time of circulation. Mean corpuscular hemoglobin, platelet count, and red cell distribution width were different between circulated and non-circulated blood, however no differences were found between the pumping systems in any parameter. Red blood cell count, total hemoglobin, and hematocrit were not affected by time or treatment. The changes observed in this study have implications for the use of extracorporeal circulation in the clinical setting and in future use of blood as a potential organ perfusion medium.Master of Science
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Yogaratnam, Jeysen Zivan. "The effects of preconditioning coronary artery disease patients with hyperbaric oxygen prior to coronary artery bypass graft surgery & cardiopulmonary bypass." Thesis, University of Hull, 2011. http://hydra.hull.ac.uk/resources/hull:4803.
Full textAbstract:
IntroductionCoronary artery bypass graft (CABG) is associated with periods of ischaemia and reperfusion, which may lead to myocardial dysfunction. In clinical studies, hyperbaric oxygen (HBO2) treatment following an acute myocardial infarction (AMI), has been shown to limit myocardial injury and improve myocardial function. The primary efficacy objective of this study was to determine if systemically preconditioning coronary artery disease (CAD) patients with HBO2, prior to first time elective on cardiopulmonary bypass (CPB) CABG surgery, leads to a remote preconditioning like effect that is capable of improving myocardial function following CABG. The main secondary objectives of this study were to assess the safety of HBO2 preconditioning and, its effects on myocardial injury and post operative intensive care unit (ICU) length of stay. The exploratory secondary objectives were to assess the effects of HBO2 preconditioning on surrogate serum biomarkers of endothelial and neutrophilic adhesiveness and, myocardial biomarkers of cardioprotection. Methods In this single centre, randomised control study, 81 patients, who were having first time elective on CPB CABG surgery, were recruited. 40 were randomised to the Control Group and 41 to the HBO2 Group. Treatment with HBO2 preconditioning was completed approximately 2 hours prior to CPB and consisted of two 30 minute sessions of 100% oxygen at 2.4 atmospheres (ATA) separated 5 minutes apart. Efficacy was measured by determining peri-operative haemodynamic measurements using a pulmonary artery (PA) catheter. Safety was measured by collecting peri-operative data on myocardial injury and adverse events (AEs) and, post operative days spent in ICU. Using collected peri-operative venous blood, myocardial injury was determined by measuring the concentration of serum Troponin-T. In these same venous blood samples, endothelial and neutrophilic adhesiveness was indirectly assessed by measuring the concentrations of sE-selectin, sP-Selectin and sICAM-1 and, sPSGL-1, respectively. Using intra-operative right atrial biopsies, the degree of cardioprotection provided by HBO2 preconditioning was determined by measuring the quantity of myocardial eNOS and Hsp72. Analysis of the serum and myocardial biomarkers were done by ELISA.Results Compared to the Control Group, the HBO2 Group demonstrated a significant improvement in left venticular stroke work (LVSW) 24 hours post CPB (p=0.005). While there were no significant safety findings, there were fewer cardiovascular, pulmonary, renal and neurological AEs in the HBO2 Group. This group also had a significantly shorter post operative ICU length of stay. 1 hour post HBO2 preconditioning, the concentration of sPSGL-1 increased significantly in the HBO2 Group. At all time points, the peri-oprative concentration of sPSGL-1 was higher in the HBO2 Group but none of the changes were significant. The latter was also the case for the peri-operative concentration of sP-Selectin, apart from following the period of ischaemic and reperfusion, when it was lower in the HBO2 Group. Intra-operatively, the concentration of sE-Selectin increased significantly in the HBO2 Group and was higher in this group throughout the peri-operative period. During this intra-operative period also, the concentration of sICAM-1 was higher in the HBO2 Group and the increase was particularly significant following the period of ischaemia and reperfusion. 24 hours post CPB, the concentrations of all the serum soluble adhesion molecules were higher in the HBO2 Group. No significant differences were observed between the groups with respect to the concentrations of serum Troponin-T and, the quantity of myocardial eNOS and Hsp72. However, in the HBO2 Group, the peri-operative concentrations of serum Tropinin-T, eNOS and Hsp72 were lower. Furthermore, while there was a pre-CPB reduction of both eNOS and Hsp72, following ischaemia and reperfusion, the quantity of both these myocardial biomarkers were increased. Conclusion From this study, it can be concluded that HBO2 preconditioning of patients with CAD prior to on CPB CABG, is capable of improving myocardial function 24 hours post CABG. Additionally, the data suggest that this may also be a safe modality of treatment as it did not lead to significant post operative AEs, limited peri-operative myocardial injury and reduced post operative ICU length of stay. It also led to increased post operative concentrations of the measured surrogate biomarkers of endothelial and neutrophilic adhesiveness, with a number of significant peri-operative changes. Finally, while HBO2 treatment did not lead to significant changes in the myocardial biomarkers of cardioprotection, the quantities of these increased in the HBO2 Group following ischaemia and reperfusion, suggesting that it may be capable of inducing endogenous cardioprotection following ischaemia and reperfusion.
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Vedin, Jenny. "Coronary artery bypass surgery without extracorporeal circulation /." Stockholm, 2005. http://diss.kib.ki.se/2006/91-7140-507-0/.
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El-Habbal, Magdi Hassan Ali. "Inflammatory changes during cardiopulmonary bypass surgery and their modulation by modified ultrafiltration in children." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.285492.
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Hirao, Shingo. "Recombinant human soluble thrombomodulin prevents acute lung injury in a rat cardiopulmonary bypass model." Kyoto University, 2018. http://hdl.handle.net/2433/232083.
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