View clinical trials related to CABG.
Filter by:To study the reliablity of MSFP and stressed volume to follow volume loading and to predict fload loading responsiveness in patients after elective coronary artery bypass grafting (CABG) surgery.
Assessment of myocardial ischemic-reperfusion injury during off- and on- pump CABG.
Remote ischemic preconditioning (RIPC) with transient upper limb ischemia/reperfusion provides peri-operative myocardial protection, is safe and improves prognosis in patients undergoing elective CABG surgery. The signal transfer from limb to heart is unknown. Thus, the aim of this study is to identify the pathways which transfer the cardioprotective signal from the ischemic/reperfused extremity to the heart in humans undergoing surgical coronary revascularization.
To diagnose acid base disturbances using blood gas analysis, multiple approaches are currently in use. These include the classic Henderson-Hasselbach bicarbonate approach and the physiochemical approach by Stewart1. All have shown to be mathematically compatible2. Diagnosing the metabolic component of acid base disturbances relies on the assessment of the so called ion gaps: the anion gap for the classic acid-base approach and the strong ion difference (SID) for the Stewart approach. This gap may unveil unidentified anions to provide a more accurate diagnosis. In particular they allow differentiating between relative hyperchloremia and other strong ions such as lactate, ketones, salicylates, citrate and ethylene glycol3. The accuracy of both gaps relies on the estimation of the weak acid dissociation: A-. This A- is dependent on the total concentration of weak acids (Atot) of which albumin is the most important and the effective dissociation constant for these (Ka), which determines the dissociated fraction of the Atot. This dissociation fraction needs to be accounted for in the ion gaps. This is reflected in the recommendation to correct the anion gap for albumin and incorporated in the SID which includes a factor for albumin by design3,4. However, the correction factor for albumin is currently based on data from animals and healthy volunteers4-9. In the critically ill albumin and protein content are very different compared to healthy volunteers, most notably in sepsis. Further, it is unknown if subunit composition of albumin is different in these patients. In addition, different protein species may be either up or downregulated in the critically ill1,8,9.Therefore from a pathophysiological point of view Atot and Ka and thus A- may differ in the critically ill. However it has not been previously investigated if and to what extent these matters affect Atot and Ka and therefore A- in this population. In addition, previous studies looking into this values showed a higher than expected value of unmeasured anions from the gap calculations. Despite rigorous experimental effort including high performance liquid chromatography, the origin of these unmeasured anions have not yet been elucidated17-20. However if the assumptions made in the Stewarts approach would not be valid, the existence of these unknown anions may have to be questioned. Thus it is of great interest to experimentally determine the exact contribution of the weak acids and their dissociation in sepsis. This could have major implications for these patients because different assumptions will ultimately lead to alterations in their calculated anion gap or SID. This may reduce unnecessary diagnostic test, alter final diagnosis and hence alter therapy. In this study the investigators aim to experimentally determine the Atot and Ka and thus their dissociated fraction A- in critically ill septic patients admitted to the intensive care unit by using in vitro CO2 tonometry, plasma dialysis and Marquardt regression analysis. In addition, as a control the investigators will do the same for patients admitted to the intensive care after routine cardiac surgery. Furthermore Atot and Ka values for both groups will be compared to values obtained from human volunteers in a previous study4. To achieve this, the investigators will plot CO2 versus pH titration curves from plasma samples of these patients. The investigators will then use Marquardt nonlinear regression analysis to quantify Atot and Ka and the SID by simultaneously solving for these parameters21. To make the quantification for Atot and Ka more robust, the investigators will also perform the same experiments after dialyzing the obtained plasma samples against a crystalloid solution of known composition in order to eliminate errors related to estimation of the SID. Finally, Atot and Ka values for both groups will be compared to values obtained from human volunteers in a previous study4. For application in the bicarbonate and base excess centred frameworks, Atot and Ka values will be related to albumin and protein content to update the correction factor for the anion gap in critically ill.
Hypothesis: Deep breathing exercises performed during the first two months after cardiac surgery, will improve pulmonary function and patient-perceived quality of recovery. Specific aim: To evaluate the effectiveness of breathing exercises performed with a mechanical device for positive expiratory pressure during the first two months after cardiac surgery compared to a control group performing no breathing exercises. Design: A prospective, randomized, controlled two-center study.
Participants undergoing Off-CABG will be randomized 1:1 to one of the following groups: - treatment with CirQlator TM Intrathoracic Pressure Regulator (ITPR) - no ITPR .Anesthesia will be standardized for both groups. The groups will be compared based on the differences in vasopressor use, the number and amount (in milliliters) of intravenous fluid boluses required and hemodynamic changes noted, including systemic blood pressure, pulmonary arterial pressure, pulse pressure, heart rate (recorded most reliably from the arterial line), cardiac output (CO), cardiac index (CI), mixed venous oxygen saturation (SVO2), SVR, pulmonary vascular resistance (PVR), and stroke volume (SV). Specifically, we will compare the groups based on the mean number of intravenous fluid boluses, mean amount of norepinephrine and epinephrine infusion required, the number of recorded systolic blood pressures < 90 mmHg, and number of CI < 2.0 L/min/m2. We will also compare the number of times the surgeon must reposition the heart for treatment of hypotension, and ascertain whether the ITPR will help patients tolerate the cardiac displacement better, thus decreasing the time required to complete the bypass graft anastamosis. ECG will be monitored intraoperatively for signs of ischemia including ST changes, greater than 1mm depression or elevation. Postoperatively, we will record the need for and amount of diuretic required. We hypothesize that in this pilot study, patients undergoing OPCAB who are treated with CirQlator TM Intrathoracic Pressure Regulator (ITPR) will achieve higher blood pressures and cardiac output and require less intravenous fluids and vasopressor administration than patients managed without the ITPR.
This research is being done to see if giving a hormone called GLP-1 can improve heart function and reduce length of stay in the Cardiac Surgical Intensive Care Unit (CSICU) in people who have non-emergent coronary artery bypass graft (CABG) surgery.
This is a phase 2 study that evaluates the effect of intravenous administration of a bolus EPO on the activation of EPOR-signal transduction cascades and myocardial apoptosis during cardiopulmonary bypass surgery. Human atrial and ventricular tissue will be collected during CABG surgery for 3-vessel disease for the assay of EPOR signaling and apoptosis. Two atrial specimens will be collected before and at the end of cardiopulmonary bypass (CPB). Concomitantly, two transmural ventricular biopsies will be obtained, at the start and at the end of CPB. Immediately after obtaining the first atrial biopsy, one bolus of EPO will be administered intravenously. The atrial tissue will be split and appropriate sections will be frozen for determination of baseline expression or activity of a number of molecules including Erk1/2, STAT5, Akt and caspase-3 or embedded in paraffin for immunohistochemistry. Ventricular tissue will only be processed for immunohistochemistry. Additionally, plasma will be collected before the procedure and for up to 30 days post-procedure to examine release of markers of both myocardial ischemia and stress (CK-MB, Troponin T and NT-proBNP) and renal dysfunction (cystatin C, creatinine for eGFR). Before initializing the randomised study, a pilot study will be performed with 5 subjects that will not be treated to evaluate the feasibility of myocardial sample collection. Initiation of the randomised study will only commence if baseline activity of EPOR-STC can be determined in the atrial tissue and caspase-3 positive cells can be identified in the second ventricular biopsy.
Angiotensin converting enzyme (ACE) inhibitors have been shown to improve survival and to reduce the risk of cardiovascular events in some groups of patients following myocardial infarction. This study is designed to test whether early initiation (≤7 days) of an ACE inhibitor post-coronary artery bypass graft (CABG), would reduce cardiovascular events. The trial was a double-blind, placebo controlled study of 2,553 patients randomly assigned to quinapril, target dose 40 mg daily or placebo, followed up to 43 months.