Clinical Research Directory

Comparison Of The Effects Of Regional Anesthesia On Brain And Carotid Artery Oxygenation In Shoulder Surgery

The aim of our study was to compare the effects of interscalene block alone and the combination of interscalene block and superficial cervical block on cerebral oxygenation, carotid artery diameter, intraoperative hemodynamics, laboratory parameters, clinical course and postoperative pain in patients undergoing shoulder surgery.

View of Cerebral Perfusion in Liver Transplantation

Investigator's aim in this study is to compare the more accessible and low-cost Carotid Doppler USG measurements, which are relatively more difficult to access, costly, and have technical disadvantages, and to demonstrate their superiority over each other in the evaluation of cerebral perfusion in liver transplantation surgeries, without any invasive intervention to the patient.

Evaluation of Cerebral Oxygenation During Orthopedic Surgeries Performed in the Beach Chair Position Under General Anesthesia

The goal of this observational study is to determine the correlation between cerebral oxygenation values measured by near-infrared spectroscopy (NIRS) and other routine monitoring parameters in patients placed in the semi-sitting position. The primary questions investigated are : Do NIRS values correlate with heart rate, invasive mean arterial pressure, and end-tidal carbon dioxide? Do NIRS values reflect changes observed in arterial blood gas analysis? Are cerebral perfusion-related parameters associated with patients' comorbidities such as diabetes, obesity, and hypertension? Researchers will compare routine noninvasive monitoring (heart rate, blood pressure, peripheral oxygen saturation) with invasive arterial monitoring and NIRS to assess whether NIRS provides additional information for evaluating cerebral perfusion. Participants will be monitored for: Heart rate Invasive mean arterial pressure End-tidal carbon dioxide Arterial blood gas changes Cerebral oxygenation with NIRS Patients' comorbidities (e.g., diabetes, obesity, hypertension) will also be recorded, and their association with perfusion-related parameters will be analyzed.

Assessment of the Cerebral Perfusion During the Period of Deep Hypothermia at 18°C in Patient Undergoing Pulmonary Endarterectomy Surgery.

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 Effects of the Female Hormones on Cerebral Perfusion

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.