View clinical trials related to Cerebral Autoregulation.
Filter by:Carotid endarterectomy (CEA) is used to treat symptomatic extracranial internal carotid artery stenosis. The occult stroke of CEA patients evaluated by magnetic resonance imaging 3 days after operation was as high as 17%. Cerebral blood flow autoregulation (CA) is the ability of the brain to maintain the relative stability of cerebral blood flow, and cerebral oxygen index (Cox) can be used to reflect CA. A negative value of cerebral oxygen index or a value near zero indicates that CA is complete, and cerebral oxygen index close to 1 indicates that CA has lost its ability. In theory, real-time monitoring of CA function by cerebral oxygen index and individualized management strategy with this goal can potentially reduce perioperative ischemic brain injury. The purpose of this study is to explore the influence of the management strategy of monitoring CA function based on regional cerebral oxygen saturation on the postoperative neurological complications of CEA patients.
The sudy objective is to evaluate the cerebral haemodynamic status in different ranges of systemic arterial pressure in patients with septic shock by noninvasive tools, transcranial doppler and intracranial compliance by mechanical sensor (B4C). Patients participating in the study will be submitted to different levels of arterial pressure, titrated with vasopressor and them their cerebral hemodynamic variables will be evaluated,
The aim of the study is to evaluate autonomic function and cerebrovascular control in 30 healthy subjects by means of noninvasive analysis of time series variability. To this extent, heart period, systolic and mean arterial blood pressure, cerebral blood velocity, peripheral resistances, respiration will be recorded from subjects during an orthostatic challenge. The interactions between autonomic cardiovascular function, cerebrovascular and peripheral control will be evaluated exploiting the most advanced signal processing techniques.
Cerebral autoregulation is defined by the capacity of the brain to maintain a constant cerebral blood flow (CBF) despite variations of arterial pressure. However, when the arterial pressure is below a critical threshold, cerebral blood decreases. This critical threshold is called the lower limit of cerebral autoregulation (LLA). Cardiopulmonary bypass is a unique environment wherein systemic blood flow is totally controlled by the cardiopulmonary bypass pump. High pump flows combined with low arterial pressures has been shown to not compromise neurologic postoperative outcomes. Our hypothesis is that that LLA may depend on the cardiopulmonary bypass flow, ie the LLA may decrease when the cardiopulmonary bypass flow increases, explaining why low arterial pressure may be well tolerated.
This clinical trial aims to learn whether blood pressure (BP) guided by individualized cerebral autoregulation (CA) is safe and provides a better prognosis than a fixed target in patients with ischemic stroke after endovascular therapy. The BP of participants will be managed at least 48 hours after revascularization. Researchers will compare the CA-guided BP group with the fixed target BP group to mainly see if individualized BP could help more patients to have their neurological function improved at seven days.
Objective: The objective of this study is to describe the physiology of the cerebral autoregulation over time during extreme low blood pressures (BP). Study design: This is a retrospective data collection study. During the Personalized External Aortic Root Support (PEARS) procedure extreme low blood pressures < 65 mmHg are medically induced. Hemodynamic and neurophysiologic data is for clinic purposes stored. Study population: All patients requiring a PEARS study at the Amsterdam University Medical Centers, location Amsterdam Medical Center (AMC). Investigation: Cerebral parameters during sustained low blood pressures are monitored with the transcranial doppler (TCD) for cerebral blood flow velocity (CBFV), near infrared spectroscopy (NIRS) for cerebral tissue oxygenation (rS02) and the electroencephalography (EEG) for the cerebral activity. Blood pressure waveforms are retrieved from an invasive arterial catheter. Besides, blood gasses during the low blood pressures and cardiac output, measured with a Schwan Ganz catheter are collected as well as electronic health records (EHR) (like age, gender and weight). All these devices are implemented as stated in the clinic protocol. Main study parameters/endpoints: The investigators will describe the cerebral autoregulation (CA) in several ways to retrieve a cut-off or lower limit of the CA where the regulation is either intact or impaired. First the static CA will be created with the mean arterial pressure (MAP) and mean cerebral blood flow (CBFm), second, the CA will be described with the mean flow velocity index (Mx, a method which calculates the correlation between the MAP and CBFm), COX (correlation between MAP and rS02) and with data of the EEG. After retrieval of the cut off or lower limit, the CA below this point will be described over time to check for differences.
Introduction. Initiation of acute kidney replacement therapy (KRT) is common in critically ill adults admitted to the intensive care unit (ICU), and is associated with increased morbidity and mortality. KRT has been linked to poor neurocognitive outcomes, leading to a reduced quality of life, as well as increased utilization of healthcare resources. Adults initiated on dialysis in the ICU may be particularly at risk of neurocognitive impairment, as survivors of critical illness are already predisposed to developing cerebrovascular disease and cognitive dysfunction over the long-term relative to healthy controls. Regional cerebral oxygen saturation (rSO2) may provide a critical early marker of long-term neurocognitive impairment in patients in this population. The INCOGNITO-AKI study aims to understand cerebral oxygenation in patients undergoing KRT, either continuous or intermittent, in the ICU. These findings will be correlated with long-term cognitive and functional outcomes, as well as structural brain pathology. Methods and analysis. 108 patients scheduled to undergo treatment for acute kidney injury with KRT in the Kingston Health Sciences Centre ICU will be recruited into this prospective observational study. Enrolled patients will be assessed with intradialytic cerebral oximetry using near infrared spectroscopy (NIRS). Delirium will be assessed daily with the Confusion Assessment Method-Intensive Care Unit (CAM-ICU) and delirium severity quantified as cumulative CAM-ICU-7 scores. Neurocognitive impairment will be assessed at 3- and 12-months after hospital discharge using the Kinarm and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Structural brain pathology on MRI will also be measured at the same timepoints. Driving safety, adverse events, and medication adherence will be assessed at 12-months to evaluate the impact of neurocognitive impairment on functional outcomes. Ethics and dissemination. This study has been approved by the Queen's University Health Sciences and Affiliated Teaching Hospitals Research Ethics Board (Approval number: DMED-2424-20). Results will be presented at critical care scientific conferences and a lay summary will be provided to patients and families in their preferred format.
The transitional period, defined as the first 72 hours after preterm birth, is often characterized by a significant hemodynamic instability and may also be associated with an impairment of cerebral autoregulation, with relevant clinical implications. The moving correlation coefficient between cerebral oxygenation and heart rate, also defined as TOHRx, has been previously proposed as a marker of cerebrovascular reactivity and provides an indirect estimation of cerebral autoregulation in preterm infants. This study aims to evaluate whether different antenatal, perinatal and postnatal factors may influence cerebrovascular reactivity in very preterm infants during the transitional period.