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Current Possibilities in Use of a Centrifugal Pump in the Cardiac Sugery
Mlejnský, František ; Lindner, Jaroslav (advisor) ; Lonský, Vladimír (referee) ; Vaněk, Tomáš (referee)
Current Possibilities in Use of a Centrifugal Pump in the Cardiac Sugery Abstract Currently, the most commonly used technical solution for pumping blood during extracorporeal circulation during cardiac surgery, as well as for some types of ECMO (extracorporeal membrane oxygenation) are either a roller pump or centrifugal pump. Due to its advantages the centrifugal pump is mainly used for prolonged extracorporeal circulation in cardiac surgery and as a heart and / or lung support system. In current literature there is a lack of compelling scientific evidence that would clearly support its use in a routine cardiac surgery. The aim of our study was to compare both types of currently used blood pumps in longer cardiac procedures with deep hypothermic circulation arrest. In a randomized clinical study we had selected a group of patients that underwent a pulmonary endarterectomy (PEA) in order to demonstrate the positive effects of the centrifugal pump on the postoperative inflammatory reactions. There were no statistically significant differences between these two pumps when other clinical and laboratory parameters were observed. Based on the hypothesis that significant temperature changes during cardiac procedure with a deep hypothermia can affect sealing pressure of the endotracheal tube cuff, we performed a...
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Fibrinolysis in cardiac surgery and possibillity of its control
Špegár, Ján ; Vaněk, Tomáš (advisor) ; Cvachovec, Karel (referee) ; Stříteský, Martin (referee)
Local and systemic application of tranexamic acid in heart valve surgery: a prospective, randomized, double blind LOST study SUMMARY The study was performed to examine a possible augmentation of systemic administration of tranexamic acid by the additional topical application during heart valve surgery in the post-aprotinin era. One-hundred patients were enrolled in the study and all the patients were given tranexamic acid intravenously. The participants were randomized into two groups (A, n = 49; B, n = 51), and before commencing the sternal suturing, the study solution (group A: 250 ml of normal saline + tranexamic acid 2.5 g, placebo group B: 250 ml of normal saline) was poured into the pericardial cavity. The cumulative blood loss (geometric means [95% confidence intervals]) 4 h after the surgery was 86.1 [56.1, 132.2] ml in group A, and 135.4 [94.3, 194.4] in group B, test for equality of geometric means P = 0.107, test for equality of variances P = 0.059. Eight hours after the surgery, the blood loss was 199.4 [153.4, 259.2] ml in group A, 261.7 [205.1, 334.0] ml in group B, P = 0.130 and P = 0.050, respectively. Twentyfour hours postoperatively the blood loss was 504.2 [436.0, 583.0] ml in group A, 569.7 [476.0, 681.7] ml in group B, P = 0.293 and P = 0.014, respectively. The proportion of patients...
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Haemocoagulation changes caused by cardiopulmonary bypass
Šnircová, Jana ; Vaněk, Tomáš (advisor) ; Kvasnička, Jan (referee) ; Kunstýř, Jan (referee)
The aim of preliminary and experimental prospective, randomized study was to search for thromboelastography signs of fibrinolysis, their impact on postoperative blood loss and need of transfusion in coronary surgery. In preliminary study we had compared results in 20 patients scheduled for coronary surgery (10 patients OPCAB, 10 patients conventional CABG). Completely expressed thromboelastographic signs of hyper-fibrinolysis had been detected in 2 on-pump patients and partial signs of increased fibrinolytic activity had been noticed in other 2 patients originating from the same group, unlike OPCAB group, in which no signs of fibrinolysis had been observed. However, differences between the evaluated groups in that trial had not reached statistical significance due to a small number of study subjects. In experimental study, 65 patients scheduled for coronary surgery were randomized into three groups: A - conventional coronary artery bypass grafting, B - off-pump surgery, C - coronary artery bypass grafting with modified, rheoparin coated ardiopulmonary bypass with the avoidance of re-infusion of cardiotomy blood into the circuit. On the completion of peripheral bypass anastomoses, highly significant inter-group differences were found in the thromboelastographic parameter lysis of set time at 60 min of...
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Hemocoagulation and its influencing of contact with body cavities lining, especially pericardium
Vymazal, Tomáš ; Cvachovec, Karel (advisor) ; Stříteský, Martin (referee) ; Vaněk, Tomáš (referee)
Body cavity surgical procedures have been arising. The surgery is complex and often extending two hours on patiens with serious comorbidities and over 65 years of age. The major cavities are the thorax, abdomen and skull. Any body cavity surgical procedure is accompanied by touch of blood and biological membrane leading to release of tissue factor and effecting clot formation pathways. The blood is due to a clear site of procedure succkled out of a body and in most cases is not transfused back: that is why it does not affect the coagulation pathways. If a masive bleeding is expected a cell - saving machine could be used to recuperate and retransfuse the patient's blood. The cell -saver membrane can separate large molecules and substances (fat, blood clot) but is not able to catch various cytokines and tissue factor. These are associated with clot formation pathways disturbances. Coagulation disorder is very serious leading to a massive hemorrhage which is ussualy treated with allogeneic blood transfusion. Allogeneic blood transfusion is associated with poor wound heeling and higher risk of infection complications in postoperative period. In the first part of my work the influence of coagulation system following contact a patient ́s blood and biological body membrane was evaluated. I also wanted to answer...
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Antiproliferative, antioxidant and anti-inflammatory activity of quinones, terpenoids and their derivatives
Přibylová, Marie ; Vaněk, Tomáš (advisor) ; Smrček, Stanislav (referee) ; Hájek, Miroslav (referee)
Plant compounds play an important role in human medicine. They are a source of new drugs or serve as an inspiration for drugs' development. This thesis presents a study about syntheses of derivatives and biological activities of two groups of natural products, quinones and terpenoids. Terpenoids are plant secondary metabolites which are known for their antimicrobial, anti-inflammatory and anti-tumoral activities. We have focused on two representatives, paclitaxel and carvacrol. GnRH-paclitaxel anti-tumor conjugates potentially suitable for targeted delivery to cancer cells were prepared. Their antiproliferative activities in vitro were evaluated on MCF-7 cancer cell line and cytotoxicity in rat hepatocytes. Carvacrol and its derivative were tested for its possible anti- inflammatory effect, which was assessed in vitro as their potential to inhibit prostaglandin E2 biosynthesis via cyclooxygenase pathway. Quinones, other targets of the thesis, are well-known for biological activities similar to terpenoids. Thymoquinone, juglone and their derivatives were tested in vitro as inhibitors of cyclooxygenases and 5-lipoxygenase. Derivatives of juglone were prepared to help us to suggest structure-activity relationship of this compound. Thymoquinone and its derivatives were evaluated for their antioxidant capacity...
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The synthesis of stable O-acetyl-adenosine diphosphoribose analogs and inhibitors of sirtuins
Dvořáková, Marcela ; Vaněk, Tomáš (advisor) ; Jindřich, Jindřich (referee) ; Krečmerová, Marcela (referee)
Acetylated adenosine diphosphoribose (OAADPR) is a product of protein deacetylation catalysed by class III of histone deacetylases called sirtuins. Sirtuins deacetylate histones and other proteins by unique mechanism coupled with consumption of stoichiometric amount of NAD+ . Sirtuins and OAADPR are implicated in the regulation of gene transcription, signalling and metabolic pathways and lifespan extension, thus preventing the development of age-related diseases. Even though, sirtuins are well studied, the exact biological role of OAADPR remains mainly unknown. Its further exploration is restricted by OAADPR's proneness to enzymatic hydrolysis. Therefore, non-hydrolysable analogues of OAADPR are needed to establish its biological function. These analogues are also expected to be competitive inhibitors of sirtuins, which may reveal their potential as therapeutic agents. A series of OAADPR analogues in which the acetate moiety was replaced with alkylcarbonate functionality has been synthesized. The studies of alkylcarbonate migration on furanoside scaffold have established the stability of alkylcarbonate vs. acetate under various conditions. Generally, alkylcarbonates are more stable than acetate under acidic or neutral conditions whereas under basic conditions they seem to be less stable....
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