View clinical trials related to Cerebral Ischemia.
Filter by:Background: Our prior work with combination argatroban + recombinant tissue plasminogen activator (rt-PA) (ARTSS-1: Phase IIa low-dose safety study; n=65 and ARTSS-2: Phase IIb randomized low and high-dose study; n=90), demonstrated safety of the two drugs when delivered concomitantly and recanalization rates were greater than with historical controls. Further, interim analysis of neurological outcomes at 75 patients of the randomized Phase IIb trial, demonstrated a signal of efficacy when compared to control (rt-PA alone) patients. However, rt-PA fails to reperfuse brain in most patients with large thrombi, prompting several recent randomized clinical trials which have demonstrated that intra-arterial therapy (IA) following rt-PA substantially improves outcome in patients with distal carotid or proximal middle cerebral artery occlusions. As a result, rt-PA + IA has become the new standard-of-care for many patients with large arterial occlusions such as those treated in ARTSS-1 and 2. Therefore, this study is necessary to explore the feasibility and safety of adding Argatroban in acute ischemic stroke patients who also receive rt-PA followed by IA. Primary Objective: To demonstrate the feasibility and safety of treating stroke patients with Argatroban who undergo usual thrombolysis care (intravenous rt-PA followed by IA). Secondary Objectives: 1. Assess rates of ultra-early recanalization at commencement of IA; 2. Assess the completeness and pattern of reperfusion as obtained by IA; 3) Assess clinical outcome
The purpose of this study is to use an iatrogenic model of stroke, meaning those strokes inadvertently caused by endovascular coiling of elective aneurysms, to study the biology of stroke in humans.
Traumatic brain injury (TBI) affects 1.5 million patients per year in the United States, resulting in more than 50,000 deaths and more than 230,000 hospitalizations annually. Approximately 90,000 of these patients will suffer permanent impairment and more than half will experience short-term disability. Secondary injury processes play a critical role in the development of ischemia after trauma to the central nervous system and occur hours-to-days after the primary insult. Ischemia can lead to cerebral infarction or stroke. Ischemia has been described as the single most important secondary insult and has been identified histologically in approximately 90% of patients who die following closed head injury. Several factors resulting in post-traumatic cerebral ischemia have been identified: increased intracranial pressure (ICP), systemic arterial hypotension, and cerebral vasospasm. Cerebral vasospasm has been described as a sustained arterial narrowing. Clinically, the onset of new or worsening neurological symptoms is the most reliable indicator of cerebral vasospasm following a ruptured cerebral aneurysm. However, cerebral vasospasm is often unrecognized in patients suffering from moderate to severe TBI. These patients frequently have altered mental status due to the primary brain injury. In addition, they require narcotics for their pain and paralytics and/or sedatives while on a mechanical ventilator for airway protection. Thus, relying on the neurological exam to observe deteriorating neurological signs consistent with post-traumatic vasospasm (PTV) is reliable. While the etiology and outcome of patients with vasospasm secondary to ruptured aneurysm is well documented, the clinical significance of PTV after TBI is unknown. A better understanding of the role of cerebral autoregulation in the development of cerebral vasospasm could provide the answer. This proposal is for a pilot observational study describing the association of the impairment of cerebral autoregulation as measured by near infrared spectroscopy (NIRS) with the development of clinically significant vasospasm in patients with moderate to severe TBI. The information will serve as preliminary data for further study.
Safety and effect of SANGUINATE on patients DCI following SAH.
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.
The purpose of this study is to determine whether there is a significant decrease in cerebral oxygen saturation in hypertensive patients undergoing major abdominal surgery and their correlation with standard monitoring parameters.
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.
Study objectives: The main objective of this study is to determine the feasibility of implementing measures in the intensive care unit (ICU), based on a physiological algorithm, to reverse decreases in cerebral oxygen saturation using, near-infrared spectroscopy (NIRS). Methods: Randomization of 50 patients is balanced by experimental group; control and intervention, with an allocation sequence based on a block size of ten, generated with a computer random number generator. In the intervention group ICU Staff will use NIRS to follow a physiologically guided strategy to maintain regional oxygen saturation (rSO2) within 90% of baseline values. In the control group ICU Staff will provide standard of care without the use of NIRS.
The objective of this multi-centre, randomized controlled trial is to investigate the outcome after induced hypertension versus no induced hypertension in patients with delayed cerebral ischemia (DCI) after aneurysmal subarachnoid hemorrhage (SAH), and to assess whether induced hypertension results in improved cerebral blood flow (CBF) as measured by means of perfusion-CT.
The aim of this clinical investigation is to determine the effect of intraoperative ventilation on cerebral oxygen saturation in patients undergoing arthroscopic shoulder surgery in the beach chair position (BCP)