View clinical trials related to Brain Ischemia.
Filter by:This is a pilot study to test feasibility and safety of intravenous infusion of autologous umbilical cord blood cells in the first 72 hours after birth if a neonate is born with signs of encephalopathy.
The primary objective of HOPE is to improve the accuracy of outcome prediction in anoxic-ischemic encephalopathy following cardiac arrest by bringing under close scrutiny some of the existing methods used for this purpose (e.g. somato-sensory evoked potentials). HOPE is the first multicenter prospective cohort study on coma prognosis to control for the effect of a possible self-fulfilling prophecy at the ICU and to cover the acute and neurorehabilitation phases with a long-term follow-up longer than the usual three or six months.
The purpose of this study is to measure cerebral oxygenation and cardiac output of total shoulder replacement patients undergoing general anesthesia (GA) and positive-pressure ventilation (PPV). We hypothesize that cerebral desaturation occurs frequently during GA with PPV, but is rare during GA and spontaneous ventilation. We also hypothesize that cardiac output usually is well maintained under GA in the sitting position when epinephrine is used, but that decreased cardiac output increases the risk of cerebral desaturation.
Coronary artery disease (CAD) is the leading cause of death worldwide. Patients with severe CAD are often treated with coronary artery bypass grafting (CABG). Novel treatment strategies need to be pursued to respond to the continuous increase in the risk profile of contemporary CABG patients. Surgical myocardial revascularization is commonly performed with the use of cardiopulmonary bypass (CPB). Neurological impairment following CABG may take on the form of a new-onset motor deficit or postoperative cognitive dysfunction. The former is rare, but potentially devastating. Conversely, declines in attention, memory and fine motor skills can frequently be documented. Ischemic preconditioning is a phenomenon of an endogenous protective response to organ ischemia, which is triggered by brief cycles of nonlethal ischemia and reperfusion in tissues known to be more resistant to ischemic insults. In clinical practice remote ischemic preconditioning (RIPC) is achieved by inflicting short periods of ischemia with intermittent restitution of flow to the upper extremity. This intervention has been shown to be effective in the reduction of myocardial injury in cardiac surgical patients. The hypothesis tested in this research proposal is that RIPC will decrease the extent of postoperative neurological injury following CABG. In this research project, 70 patients scheduled for an elective CABG will be recruited at a single center. They will be randomly allocated to either undergo RIPC (intervention arm) or a sham procedure (control arm). Inflating a blood pressure cuff to 200 mmHg for 5 min will induce RIPC, thereby inducing a brief period of ischemia. This will be followed by a 5-minute arm reperfusion. In total, three cycles of arm ischemia and reperfusion will be induced in this fashion. All patients will undergo pre- and post-procedural magnetic resonance imaging (MRI) of the brain, as well as neurocognitive testing. The array of MRI tools that will be used for the quantification of brain injury will include fluid attenuated inversion recovery, diffusion weighted and susceptibility weighted imaging, coupled with resting state functional MRI. The investigators aim to determine whether RIPC can reduce the adverse impact of CPB on neurological outcome as evaluated by MRI detectable brain ischemia and neurocognition.
To compare the effectiveness of unilateral pulmonary collapse (right lung) to bilateral pulmonary collapse for cardiac de-airing in open left-sided heart surgery.
Rationale The only proven therapy for acute stroke is tPA within 4.5 hours of symptom onset. This is the standard of care for patients presenting to our hospital within that time frame. Thrombolysis outside the 4.5 hour window is considered only on experimental or compassionate grounds. Tenecteplase (TNK) is a genetically modified variant of tPA that has many theoretical advantages in acute stroke. Studies show that systemic plasminogen activation is higher after tPA administration, relative to TNK and this is associated with an increased risk of bleeding events. Imaging cerebral blood flow (CBF) with MRI (perfusion weighted imaging-PWI) and CT perfusion (CTP) can be performed routinely with standard clinical scanners. Patients with evidence of large volumes of tissue with low CBF, that is also structurally intact, as demonstrated by either normal signal on Diffusion weighted imaging (DWI) or normal cerebral blood volume (CBV) are considered to have penumbral patterns. Patients with penumbral patterns appear to be the ideal candidates for thrombolytic therapy, regardless of time from onset. Study Hypotheses 1. The primary aim of this study is to demonstrate the feasibility and safety of TNK based thrombolysis in ischemic stroke patients presenting 4.5-24 hours after symptom onset. 2. It is hypothesized that treatment with TNK in patients with penumbral patterns will be associated with reperfusion, early neurological improvement and penumbral tissue salvage. Study Design The study is planned as an open label feasibility and safety study of acute treatment with TNK in ischemic stroke patients with penumbral patterns evident on advanced MRI or CT perfusion sequences. Study Outcomes The primary outcome of this study is a safety endpoint, specifically the frequency of symptomatic hemorrhagic transformation evident on MRI or CT images on 24 h or day 5 scans. The ECASS II system for rating hemorrhagic transformation will be applied to all GRE/SWI images Significance Current treatment paradigms have not permitted success of tPA to be extended beyond narrow and limiting therapeutic window of 4.5 hours. Clearly, more effective patient selection criteria are required. Penumbral imaging is biologically plausible, practical and has been shown to be predictive of outcome. Application of these imaging techniques to the acute stroke population is the most promising strategy for extending the therapeutic window and for introducing superior thrombolytic agents.
This study examines the effect of inhaled xenon gas in the treatment of newborn infants with hypoxic-ischemic encephalopathy (HIE) in combination with cooling, which is the standard treatment for this condition. The hypothesis is that the xenon + cooling combination will produce better neuroprotection than the standard treatment of cooling alone.
1 in 1000 babies are born suffering from a lack of oxygen. This is known as hypoxic ischemic encephalopathy (HIE). Infants with this condition can suffer multiple organ problems. In particular it can affect how their hearts pump blood around their body thus leading to a poor blood supply to parts of their body such as the brain. This is known as circulatory failure and can contribute to poor long term outcomes such as cerebral palsy. To try and prevent brain damage these infants are treated with total body cooling, however this treatment can further effect how babies pump blood around the body, but also how drugs which may be used by in this condition are processed. In order to assess and treat this condition doctors need to be able to accurately measure the blood supply in an infant. However there is no agreement on how best to do this. This makes decisions about when to treat an infant difficult. Sometimes doctors may want to use drugs such as dobutamine or adrenaline but these drugs are unlicensed in babies. This study proposes to observe the way babies circulatory problems are treated in babies with HIE the in the first four days of life. In addition the study will look are two new measurements of a babies blood supply to see if they are a better measure of when an infant needs treatment. This will involve an ultrasound scan of the heart and measurement of the baby's oxygen levels from a probe placed on their hand. The study will also look at how the drug dobutamine is processed by babies. This will be done from two small extra blood tests. The aim of the study is to help clinicians refine the identification and treatment of circulatory failure in babies with HIE.
Despite recent advances in the care of mothers and newborn infants, many infants (approximately 20 per 1000 live births) continue to need resuscitation at birth. A proportion of these infants will have sustained significant injury through interruption of their blood and oxygen supply prior to delivery (perinatal asphyxia). In 2-3 babies per 1000 this will lead to brain swelling and the risk of long term brain injury called neonatal hypoxic-ischaemic encephalopathy (HIE). HIE remains a cause of neonatal death and long term disability. Early and accurate prediction of outcome would allow us to intervene during the window of the first 6 hours following birth, prior to secondary reperfusion and secondary brain injury. Estimating severity of injury can be difficult in newborn infants. Condition at birth does not predict neonatal, or longer term outcome. Biomarkers which could be measured at the time of birth and analysed at the bedside would offer these infants the best chance of timely and effective intervention. Through the BIHIVE study we have identified a number of predictive biomarkers in hypoxic-ischaemic encephalopathy. These markers are present in umbilical cord blood and have been identified through proteomic and metabolomic analysis of a stored biobank of samples from a recruited cohort of infants with perinatal asphyxia and hypoxic-ischaemic encephalopathy. We now wish to validate these biomarkers in an additional cohort, and will continue to explore new biomarkers in our stored biobank of umbilical cord samples. In addition we wish to assess our ability to predict neurodevelopmental and behavioural outcome in these infants. In this way we will determine the most robust biochemical and clinical markers for the prediction of early and medium term outcome in HIE. This study will establish the evidence base and validation of these biomarkers to the point where they can be developed into a bedside diagnostic algorithm which can be used in the labour ward to immediately identify those infants at risk of HIE in time to prevent secondary damage.
Beachchair position is used by many orthopaedic surgeons for shoulder surgery. Most patients undergoing surgery in this position have no complications. However, reported cases of postoperative neurological deficits have highlighted the risk of cerebral and spinal cord ischemia. The etiology of such complications remains unclear. The most plausible explanation for these events would be intraoperative hypotension followed by cerebral hypoperfusion. General anesthesia is commonly used for shoulder surgery in conjunction with interscalene brachial plexus blockade. During the block, local anesthetic's spread is frequently observed leading to a block of sympathetic fibres. Since all nerves located in the head and neck area go through the stellate ganglion, its block will cause a sympathetic denervation and a decrease of the peripheral vascular resistance, thus increasing the circulation in cerebral blood vessels. In normal situations, there is a vasoconstriction of the cerebral blood vessels in response to a sympathetic stimulation and a vasodilation if sympathetic fibres are blocked. Transcranial Doppler (TCD) is a non-invasive examination that provides a reliable evaluation of intracranial blood flow in real-time. It can help to detect sudden changes in perfusion and identify potential embolic events. Some studies using TCD have shown an increased ipsilateral cerebral blood flow (CBF) secondary to a reduced vascular tone associated with a stellate ganglion block. Others have shown a reduction of contralateral CBF that could theoretically increase the risk of ischemia in the affected area. This study will assess the role of interscalene nerve blockade in the protection of cerebral ischemia and preservation of cerebral autoregulation. This study will also aim to identify changes in contralateral CBF. The investigators hypothesize that: 1. Interscalene nerve block will increase CBF 2. Interscalene nerve block will not decrease contralateral CBF 3. Cerebral autoregulation will be preserved under general anesthesia in conjunction with an interscalene nerve block in this setting.