View clinical trials related to Cerebral Perfusion.
Filter by:Cardiopulmonary bypass (CPB) surgery present risk of acute postoperative neurological complications. These complications are most often postoperative cognitive dysfunction (confusion, cognitive disorders, executive disorders) with a prevalence of up to 40% at 5 years, and ischemic (stroke) with an incidence of between 0.4 and 14%. The causes are usually multifactorial, but altered cerebral perfusion during CPB surgery is an important prognostic factor. Data regarding the effect of deep hypothermia on cerebral perfusion during CPB in adult are scarce. Currently, aortic arch replacement following aortic dissection or aneurysm, and pulmonary artery endarterectomy (PAE) in the treatment of pulmonary hypertension of post embolic origin are performed under deep hypothermia. In this latter indication, the need to obtain a completely bloodless operating field necessitates complete circulatory arrest during short period of time to enable the surgeon to optimally remove the clot materials located into the pulmonary arteries. To protect the brain and avoid irreversible brain injury during circulatory arrest(s), body temperature is lowered at 18-20°C. Deep hypothermia can lead to significant arterial vasoconstriction, which can reduce the blood supply to the brai. It also increases the solubility of CO2 in the blood, leading to respiratory alkalosis, which can also lead to vasoconstriction of cerebral vessels, increasing the risk of ischemic lesions. In adult there is no consistent data on the cerebral perfusion during PAE surgery under deep hypothermia at 18-20°C. Animal studies showed that cerebral regulation seems to be preserved under these conditions. A better understanding of the effect of deep hypothermia on cerebral perfusion during PAE surgery is essential to adapt our management to limit the occurrence of postoperative neurological complications.
The aim of our study is to observe the effect of head-neck position of patients scheduled for thyroidectomy, on carotid artery blood flow, regional cerebral oxygen saturation measured using near-infrared spectroscopy technology, and postoperative cognitive dysfunction.
This prospective interventional study investigates transpharyngeal sonography (TPS) as an additional neuromonitoring strategy to assess cerebral perfusion during cardiovascular surgery. In the first part of the study the investigators will investigate the feasibility of TPS for visualization of aortic arch branches including the innominate and the carotid arteries in patients undergoing cardiac surgery with cardiopulmonary bypass. In the second part the investigators plan to adopt the investigators previous experiences on TPS to a selected population of patients undergoing ascending aortic and/or arch repair in hypothermic circulatory arrest (HCA).
Measuring brain perfusion is biased by a inter- and intrasubject variability, caused by physiological and lifestyle factors. In this study, the investigators want to investigate the effects of a different mood state (neutral, positive and negative mood), induced using subjects own memories, on both global and regional cerebral perfusion, measured with arterial spin labeling.
Measuring brain perfusion is biased by a inter- and intrasubject variability, caused by physiological and lifestyle factors. In this study, the investigators want to investigate the variations in cerebral perfusion and other brain parameters (grey matter, resting-state brain activity, brain connectivity and white matter diffusion) caused by the female sex hormones and hormonal contraception.
The purpose of this study is to determine whether cerebral blood flow and cerebral tissue oxygenation is most dependent on cardiac output or on mean arterial pressure in patients undergoing cardiac surgery with the use of cardiopulmonary bypass.
Extracorporeal membrane oxygenation (ECMO) is progressively used in critically ill patients with cardiac or respiratory failure as a bridging option for potential organ recovery. However, ECMO survivors often suffer from poor neurocognitive outcome due to neurological complications such as microembolic (ME) strokes. In venoarterial (va) ECMO circuits the pulmonary circulation, which usually serves as microembolic filter, may be bypassed and generated ME are prone to reach the brain in substantial amounts and potentially impair cerebral integrity. Although patient exposure to cerebral ME has been thoroughly investigated in cardiopulmonary bypass procedures, there is only limited research on cerebral ME in patients undergoing ECMO therapy. The primary study goal of this study is to determine the load and nature of cerebral ME in critically ill patients under va-ECMO support. We also aim to compare the results to measurements in healthy subjects und intensive care unit (ICU) patients without extracorporeal support to get a better impression on the relevance of ME generation during ECMO support.
The purpose of this study is to compare the changes measured by Somanetics Invos cerebral oximeter to the mean arterial pressure at brain level in patients having elective shoulder replacement surgery. The Somanetics Invos System measures and monitors the oxygen saturation (rS02) of blood in the brain tissues to help prevent brain injury or other complications. The investigators hypothesize that maintaining normocarbia and systemic mean arterial pressure at or above 70mmHg during general anesthesia in the beach chair position will decrease the number of cerebral deoxygenation events during the procedure.