View clinical trials related to Cerebral Ischemia.
Filter by: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 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)
The investigators hypothesized that positive end expiratory pressure (PEEP) would increase the regional oxygen saturation (rSO2).
The investigators hypothesized that both propofol and desflurane would decrease the regional oxygen saturation (rSO2) but propofol is likely to reduce rSO2 more than sevoflurane when patients are raised to the sitting position.
The purpose of this study is to determine whether a new cerebral oxygen monitoring device is effective and comparatively similar to the current approved devices.
Treatment of acute stroke is still difficult and the only specific drug approved (rtPA) can only be administered if treatment starts within 3 hours after onset of symptoms. This results in a still too small number of patients treated with rtPA ( < 15% in best clinical care institutions ). Ancrod is a differently acting biological drug which has been used for a long time but not for acute stroke treatment. STAT was the first RCT of medium size to show a significant benefit/risk ration if treatment starts within 3 hours. ESTAT was designed closely related to STAT but with a longer 6 hours window and specifically extended inclusion/exclusion criteria to avoid secondary complications possibly related to a longer time window.
Using patients receiving spinal anesthesia as a model to evaluate the treshold value of cerebral oximeter to detect the symptoms of cerebral ischemia