Perfusion
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Clinical Trial
Arterio-venous gradients of free energy change for assessment of systemic and splanchnic perfusion in cardiac surgery patients.
Adequacy of organ perfusion depends on sufficient oxygen supply in relation to the metabolic needs. The aim of this study was to evaluate the relationship between gradients of free energy change, and the more commonly used parameter for the evaluation of the adequacy of organ perfusion, such as oxygen-extraction in patients undergoing valve replacement surgery using normothermic cardiopulmonary bypass (CPB). ⋯ Gradients of free energy change may be helpful in characterising adequacy of perfusion in cardiac surgery patients independently from measurements or calculations of data from oxygen transport.
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Clinical Trial
Vacuum-assisted venous drainage in extrathoracic cardiopulmonary bypass management during minimally invasive cardiac surgery.
The diffusion of minimally invasive cardiac surgery (MICS) during open-heart surgery has increased the use of assisted venous drainage support for cardiopulmonary bypass (CPB). Peripheral cannulation with small cannulae and vacuum-assisted venous drainage (VAVD) during MICS has been adopted in our institution since 1998. After the Heartport technique (HP) experience, the trans-thoracic clamp technique is now currently used. ⋯ Mechanical ventilation time and intensive care unit stay were comparable to those recorded with conventional sternotomy. In conclusion, we found that extrathoracic CPB and VAVD during trans-thoracic clamping is a safe, simple, and effective technique for MICS. However, there is a potential risk of haemolysis and air embolism, which can be prevented with vacuum monitoring, and with the addition of gravitational drainage to reduce vacuum pressure.
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Adverse neurological events, both focal (Type I) and non-focal (Type II), have been appreciated in postoperative on-pump coronary artery bypass grafting (CABG) patients for many years. Advanced age is a significant risk factor for adverse neurological events following CABG surgery. With full knowledge that our elderly population of patients was at high risk for these untoward neurological events, we adopted a comprehensive operative and perfusion strategy in an attempt to attenuate the incidence of these complications. ⋯ From 15 August 2002 to 31 December 2005, we performed 355 on-pump CABG operations. The incidence of Type I focal injury was 0/355 (0%), the incidence of Type II non-focal injury was 9/355 (2.5%), and postoperative mortality was 2/355 (0.6%). These results compared favorably to the results predicted by the Society of Thoracic Surgeons' (STS) model, and may suggest efficacy.
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Cardiac surgery is associated with a low incidence of GI complications, but with a disproportionate mortality. A number of risk factors have become established which identify patients at risk. CPB is associated with profound reductions in mucosal blood flow. ⋯ The disparity in general and regional oxygen supply and demand results in the development of mucosal hypoxia and this cannot be attributed to CPB alone. This injury is measurable by reductions in both absorptive and barrier functions of the gut. Protection may be conferred by modulating the perfusion protocol during bypass and pharmacological interventions which modify the inflammatory response to surgery.
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Pulmonary injury during cardiopulmonary bypass is common as patient factors (smoking, pain, pneumonia) and the effects of cardiopulmonary bypass combine to compromise lung function after cardiac surgery. Lung injury follows the propagation of an inflammatory response involving cytokines, complement, neutrophils, monocytes, activated endothelial cells and platelets. Neutrophils sequester in the lung in response to chemotactic agents and release injurious oxygen free radicals and specific enzymes resulting in widespread pulmonary injury. ⋯ Aprotinin, Pentoxyfilline, Nitric oxide, Aspirin and other agents have shown benefits in lung function after cardiopulmonary bypass induced lung injury. Given the magnitude and diversity of the inflammatory response to cardiopulmonary bypass many possible interventions exist to attenuate lung injury resulting from extracorporeal circulation. Immediate clinical benefits are likely to result from successful amelioration of the processes involved.