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The use of thromboelastography (TEG) in the evaluation of coagulation in patients on intensive care unit (ICU)
Durila, Miroslav ; Cvachovec, Karel (advisor) ; Stříteský, Martin (referee) ; Kovářová Kudrnová, Zuzana (referee)
Patients in the intensive care unit are in critical condition which is often accompanied by a coagulation disorder. Sepsis as a leading cause of death in critically ill patients may be associated with both hypercoagulable state with microtrombi formation in microcirculation and with increased production of endogenous heparinoids with inhibitory effects on blood clotting. Central venous catheter and arterial catheter are established in patients for hemodynamic monitoring and these are flushed with heparin to prevent their closure. Both inputs are used for blood sampling for laboratory tests such as blood count and coagulation parameters, including thromboelastography (TEG). In the first step of the work, arterio-venous differences in coagulation parameters were investigated in patients with sepsis. Higher concentration of D-dimers and lower antithrombin activity were found in venous blood. This finding can be explained by increased antithrombin consumption in hypercoagulable state and reactive hyperfibrinolysis. Inconsistency in the site of blood sampling may then lead to misinterpretation of the pathophysiological processes in the body. No significant differences were found in TEG parameters. In the second step of the work we examined how heparin commonly used for catheter flushing affects TEG-assessed...
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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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Oxygen consumption in awake cardiac surgical patients
Pořízka, Michal ; Stříteský, Martin (advisor) ; Szárszoi, Ondrej (referee) ; Šetina, Marek (referee)
OBJECTIVES: Standard blood flow rates for cardiopulmonary bypass have been assumed to be the same for awake cardiac surgery with thoracic epidural anesthesia as for general anesthesia. However, compared to general anesthesia, awake cardiac surgery with epidural anesthesia may be associated with higher oxygen consumption due to missing effect of general anesthetics. This may result in insufficient oxygen delivery and lactic acidosis when standard blood flow rates were used. The primary aim of our study was to investigate if standard blood flow rates are adequate in awake cardiac surgery. The secondary aim was to evaluate postoperative clinical outcomes of patients undergoing awake cardiac surgery. METHODS: Forty-seven patients undergoing elective on-pump cardiac surgery were assigned to receive either epidural (Group TEA, n=17), combined (Group TEA-GA, n=15) or general (Group GA, n=15) anesthesia. To monitor adequacy of standard blood flow rates, arterial lactate, acid base parameters, central venous and jugular bulb saturation were measured at six time points during in all groups. Blood flow rates were adjusted when needed. Subsequently, early and late postoperative outcome data including hospital and 3-year mortality was recorded and compared among the study groups RESULTS: No lactic acidosis has...
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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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Methods of tissue perfusion and microcirculation assessment in experiment
Šitina, Michal ; Černý, Vladimír (advisor) ; Stříteský, Martin (referee) ; Kroužecký, Aleš (referee)
Methods of tissue perfusion and microcirculation assessment in experiment - set of experimental studies Michal Sitina Summary of doctoral thesis Doctoral study program Surgery Hradec Kralove 2013 Summary In the course of the doctoral study we have performed 4 experimental animal studies and one theoretical study using a mathematical model. Three of the studies were published in journals with an impact factor. All studies, using various research methods, deal with a microcirculation. We have assessed the method of the indicator dialysis as insatisfactory for an accurate measurement of the tissue perfusion. We have demonstrated no negative influence of a moderate hypothermia on the cerebral autoregulation of a pig. The mathematical model identified several factors, that can influence the THR test of the cerebral autoregulation. The influence of the inertia assessed the mathematical model as marginal. The methodical study of a visualisation of the surface brain microcirculation of rabbit using SDF imaging proved a high quality of visualisation. The measured parameters corresponded with the other literature values. An application of the SDF imaging of the brain surface mentioned above showed no changes of the brain microcirculation of rabbit at the early stage of the endotoxemia. Powered by TCPDF (www.tcpdf.org)
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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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Oxygen consumption in awake cardiac surgical patients
Pořízka, Michal ; Stříteský, Martin (advisor) ; Szárszoi, Ondrej (referee) ; Šetina, Marek (referee)
OBJECTIVES: Standard blood flow rates for cardiopulmonary bypass have been assumed to be the same for awake cardiac surgery with thoracic epidural anesthesia as for general anesthesia. However, compared to general anesthesia, awake cardiac surgery with epidural anesthesia may be associated with higher oxygen consumption due to missing effect of general anesthetics. This may result in insufficient oxygen delivery and lactic acidosis when standard blood flow rates were used. The primary aim of our study was to investigate if standard blood flow rates are adequate in awake cardiac surgery. The secondary aim was to evaluate postoperative clinical outcomes of patients undergoing awake cardiac surgery. METHODS: Forty-seven patients undergoing elective on-pump cardiac surgery were assigned to receive either epidural (Group TEA, n=17), combined (Group TEA-GA, n=15) or general (Group GA, n=15) anesthesia. To monitor adequacy of standard blood flow rates, arterial lactate, acid base parameters, central venous and jugular bulb saturation were measured at six time points during in all groups. Blood flow rates were adjusted when needed. Subsequently, early and late postoperative outcome data including hospital and 3-year mortality was recorded and compared among the study groups RESULTS: No lactic acidosis has...
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The influence on postoperative analgesia by preemptive analgesia
Fricová, Jitka ; Stříteský, Martin (advisor) ; Štípek, Stanislav (referee) ; Kršiak, Miloslav (referee)
The aim of our study was to assess the changes of free radicals and other biochemical parameters after nociceptive stimulation in different experimental animal models. In patiens we detected whether preemptive analgesia had a positive effect on acute postoperative pain. Objective evaluation of pain intensity is a long-term problem because the objectification of using electrophysiological and imaging methods is currently difficult and expensive, and therefore in laboratories in the Czech Republic and many other places are used the evaluation by means biochemical methods. We implemented large experimental studies using mechanical, inflammatory and visceral nociception and we found out in particular that nitroxid and hydroxyl free radicals and singlet oxygen increased significantly after nociceptive stimulation. This increase can be suppressed by antioxidants. At the same time, we showed that some parameters of metabolism lipids, carbohydrates and proteins have also been changed. In particular, we measured the free hydroxyl radicals and singlet oxygen by EPR method in the tail of living and anesthetized rats. This method is absolutely a priority and has never been used before. Earlier experimental results were partially clinically verified using different types of acute and chronic pain in humans...
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The use of thromboelastography (TEG) in the evaluation of coagulation in patients on intensive care unit (ICU)
Durila, Miroslav ; Cvachovec, Karel (advisor) ; Stříteský, Martin (referee) ; Kovářová Kudrnová, Zuzana (referee)
Patients in the intensive care unit are in critical condition which is often accompanied by a coagulation disorder. Sepsis as a leading cause of death in critically ill patients may be associated with both hypercoagulable state with microtrombi formation in microcirculation and with increased production of endogenous heparinoids with inhibitory effects on blood clotting. Central venous catheter and arterial catheter are established in patients for hemodynamic monitoring and these are flushed with heparin to prevent their closure. Both inputs are used for blood sampling for laboratory tests such as blood count and coagulation parameters, including thromboelastography (TEG). In the first step of the work, arterio-venous differences in coagulation parameters were investigated in patients with sepsis. Higher concentration of D-dimers and lower antithrombin activity were found in venous blood. This finding can be explained by increased antithrombin consumption in hypercoagulable state and reactive hyperfibrinolysis. Inconsistency in the site of blood sampling may then lead to misinterpretation of the pathophysiological processes in the body. No significant differences were found in TEG parameters. In the second step of the work we examined how heparin commonly used for catheter flushing affects TEG-assessed...
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název v anglickém jazyce není uveden
Urban, Tomáš ; Tošovský, Jan (advisor) ; Broulík, Petr (referee) ; Stříteský, Martin (referee)
An increase in a mean age of the candidates for coronary artery bypass surgery is observed due to universal trend of the whole mankind to grow old. Standard methods using cardiopulmonary bypass and cardiac arrest have achieved undisputable reputation in cardiac surgery and in low-risk procedures they present excellent results. In comparison with younger groups of patients, the elderly showed higher risk of mortality, stroke and morbidity dependent on using cardiopulmonary bypass, general anesthesia and prolonged in-hospital stay. New trends in cardiac surgery seem to be the alternative to accomplish better outcome of this high-risk group of cardiac patients. Those are generally the procedures in surgery, anesthesia and postoperative care called "minimally invasive". An effort to minimize the surgical trauma, prolonged ventilation time and length of stay in postoperative ward as well as to offer prompt verticalisation, rehabilitation and shorter in-hospital stay are the key characters of the abovementioned procedure. The "Aortic No-touch Technique" is an up-to-date method with potential to fulfill the criteria of "minimal invasiveness". This is a procedure avoiding cardiac arrest, cardiopulmonary bypass and excessive aortic manipulation, using only pedicled or free arterial grafts, as composite grafts. Our...
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