The Thoracic and cardiovascular surgeon
-
Thorac Cardiovasc Surg · Oct 1995
Postoperative neuropsychological dysfunction and cerebral oxygenation during cardiac surgery.
In 41 patients undergoing cardiac operations with extracorporeal circulation, oxidized cytochrome a,a3(CtO2), deoxygenated hemoglobin (Hb), and oxygenated hemoglobin (HbO2) were measured in brain tissue by near-infrared spectrophotometry (NIRS) intraoperatively. Monitoring also included electroencephalography (EEG) and jugular-bulb venous saturation (SBJO2). All operations were performed using membrane oxygenators, moderate hypothermia (26-28 degrees C) and pH alpha-stat management. ⋯ Neuropsychological testing by the Mini-Mental-State Test indicated reversible postoperative neuropsychological deficits in four patients. There patients had a lower CtO2 minimum compared to those without these deficits (-4.5 mumol/L v. -0.7 mumol/L; p = 0.036). These findings support the hypothesis that neuropsychological deficits in patients after cardiac surgery can be caused by intraoperative cerebral hypoxia.
-
Thorac Cardiovasc Surg · Aug 1995
Randomized Controlled Trial Comparative Study Clinical TrialAntegrade versus retrograde crystalloid cardioplegia: perioperative assessment of cardiac energy metabolism by means of myocardial lactate measurement.
The effects of retrograde and antegrade delivery of cold St. Thomas' Hospital cardioplegia were evaluated and compared in 21 patients who underwent elective myocardial revascularization. The patients were randomly separated into two groups: the antegrade group (n = 10), and the retrograde group (n = 11). ⋯ This can be related to a faster reconsolidation of mitochondrial oxidative phosphorylation in the retrograde group. For the other registered parameters, hemodynamic recovery of cardiac function, release of creatine kinase MB isoenzyme, and clinical outcome, there was no significant difference between the groups. Based on this study we conclude that retrograde delivery of a cold non-oxygenated cardioplegic solution results in a better preservation of myocardial energy reserve than antegrade delivery.
-
Thorac Cardiovasc Surg · Jun 1995
Randomized Controlled Trial Comparative Study Clinical TrialThe efficacy of amrinone or adrenaline on low cardiac output following cardiopulmonary bypass in patients with coronary artery disease undergoing preoperative beta-blockade.
We examined 20 patients undergoing coronary bypass grafting for coronary artery disease with NYHA classifications of II and III who had been treated with beta-blocking agents. Patients were randomised for administration of either adrenaline (0.1 microgram/kg/min) or amrinone (bolus 1 mg/kg, continuous infusion of 5-10 micrograms/kg/min), if following cardiopulmonary bypass their cardiac index was < 2.4 L/min/m2 with normal peripheral resistance and normal or increased right- or left-ventricular filling pressures. Over a period of 1 hour, the hemodynamic parameters mean arterial pressure (MAP), cardiac index (CI), heart rate (HR), coronary perfusion pressure (CPP), total peripheral resistance (TPR), as well as the pressure-work index (PWI) were registered or calculated. ⋯ Both substances caused a significant increase in myocardial contractility, with adrenaline showing a more potent effect than amrinone. Both substances caused a significant increase in CI with a mild increase in HR. Amrinone caused a significant drop in TPR, while MAP remained practically constant.(ABSTRACT TRUNCATED AT 250 WORDS)
-
Thorac Cardiovasc Surg · Apr 1995
The failure of retrograde continuous warm-blood cardioplegia to resuscitate cardiac function in experimental acute coronary artery occlusion and reperfusion.
The effects of retrograde continuous warm-blood cardioplegia (RCWBC) on myocardial preservation during surgical revascularization for acute coronary artery occlusion were investigated using an isolated in-situ dog heart model. The left anterior descending artery (LAD) was occluded for 60 minutes followed by 60 minutes of cardioplegic arrest and reperfusion after release of the coronary artery occlusion. Thirty one animals were divided into 3 groups according to the manner of cardioplegic arrest. ⋯ Corresponding to the functional data, myocardial pH in the occluded LAD distribution was not significantly increased by RCWBC. Although RCWBC maintained myocardial pH in the circumflex artery distribution at a significantly higher level than the other two groups of hearts undergoing cold crystalloid cardioplegia, RCWBC resulted in a substantial decline of myocardial pH in the right-ventricular free wall. These results suggest that RCWBC after 60 minutes of LAD occlusion may not provide a significant benefit in myocardial preservation compared to cold crystalloid cardioplegia delivered through either an antegrade or retrograde manner.