The Effect of Anesthesia on Cerebral Oxygenation

Study Overview
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Brief Summary
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One-lung ventilation (OLV) may cause negative changes in the oxygenation of cerebral tissue which results in postoperative cognitive dysfunction. The aim of this prospective study was to compare the potential effects of TIVA and inhalation general anesthesia techniques on cerebral tissue oxygenation and postoperative cognitive functions in patients receiving one-lung ventilation in thoracic surgery

Detailed Description
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One-lung ventilation (OLV) is a commonly used technique in thoracic surgeries. In thoracic surgeries performed with OLV, there may be changes in cerebral tissue oxygenation depending on both patient position and anesthetic technique. The effect of cerebral hypoxia on postoperative cognitive functions is controversially. Despite the ISPOCD1 study in which concluded that there were no relationship between the cerebral hypoxy and postoperative cognitive dysfunction (POCD) regional cerebral oxygen saturation decrements during surgery are listed among the POCD When OLV begins, alveolar hypoxia and arteriovenous shunt of deoxygenated blood occur in the dependant lung. And then, hypoxic pulmonary vasoconstriction (HPV) in non-ventilated lung segments occurs with increased mechanical stress. This event lead to significant physiological changes in cardiac output and pulmonary and systemic pressures In OLV, the propofol-based total intravenous anesthesia (TIVA) and inhalation general anesthesia techniques are frequently used. Recent studies have shown that unlike inhalational anesthetics, propofol does not suppress HPV, indeed increases it (Inhalational anesthetic agents reduce cardiac output more than oxygen consumption, causing a decrease in mixed venous partial pressure of oxygen, which stimulates hypoxic pulmonary vasoconstriction . Studies have shown significant reductions in cerebral oxygen saturation in thoracic surgery as a result of severe oxidative stress due to prolonged OLV and hypoxemia due to decreased functional residual capacity of the ventilated lung in the lateral decubitus position Cerebral oximetry is a method used to monitor the cerebral oxygen distribution-consumption balance and regional oxygen saturation (rSO2) in a limited area of the frontal cortex by noninvasively and continuously combining arterial and venous oxygen saturation signals of near-infrared spectroscopy (NIRS), which is a technique developed in the 1970s. Thanks to this method, perioperative physiological conditions, optimal tissue oxygenation and end-organ functions can be interpreted The aim of this prospective study was to compare the potential effects of TIVA and inhalation general anesthesia techniques on cerebral tissue oxygenation and postoperative cognitive functions in patients receiving one-lung ventilation in thoracic surgery

Official Title
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The Effect of Different Anesthesia Techniques on Cerebral Oxygenation in Thoracic Surgery

Conditions
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One-Lung Ventilation, Thoracic Surgery, Postoperative Cognitive Complications

Intervention / Treatment
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* Drug: Sevoflurane
* Drug: Propofol


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients in American Society of Anesthesiology (ASA) classification I and II Patients who would undergo thoracic surgery with one-lung ventilation (OLV) thoracic surgeries with one-lung ventilation (OLV) that will take at least 45 minutes Exclusion Criteria: Patients in ASA classification III and higher Emergency surgery Patients with known allergy to drugs used in the study Patients in New York Heart Association classification III-IV severe metabolic, renal, hepatic, central nervous system diseases, alcohol or drug addiction multiple trauma, coagulapathy, cerebral disease, dementia, hearing impairment and imperception severe obesity (a body mass index (BMI) of ≥ 35) patients with a peripheral oxygen saturation below 90 during one lung ventilation

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 80 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Group Propofol<br>anesthesia was maintained with TIVA (intravenous 125-250 µg/kg/min propofol + 0.1-0.25 µg/kg/min remifentanil infusion) | Drug: Propofol<br>* BIS values were arranged 40-60 until the end of operation, In case of tachycardia or hypertension the opioid dose was reduced, in case of bradycardia or hypertension the opioid dose was increased<br>* Other names: Remifentanil;|
| Group Sevoflurane<br>anesthesia was maintained with inhalation (sevoflurane concentration of 1-2% in 50-50% O2-air mixture). | Drug: Sevoflurane<br>* Sevoflurane %2-3 for general anesthesia maintenance, BIS values were arranged 40-60 until the end of operation, In case of tachycardia or hypertension the opioid dose was reduced, in case of bradycardia or hypertension the opioid dose was increased<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Near Infrared Spectroscopy | Cerebral oxygen saturation as measured by Near Infrared Spectroscopy | Duration of surgery | 
| Mini mental state examination (MMSE) | Mini mental state examination (MMSE) to evaluate patients' cognitive functions | 3 to 24 hours postoperative period | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| mean arterial pressure | The effect of anesthetics on mean arterial pressure | Duration of surgery | 
| heart rate | The effect of anesthetics on heart rate | Duration of surgery | 
| bispectral index | The effects of sevoflurane and desflurane on bispectral index | Duration of surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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One-lung ventilation, sevoflurane, propofol, cerebral oxygenation, postoperative cognitive dysfunction