The Effect of Anesthesia on Cerebral Oxygenation
Condition: One-Lung Ventilation; Thoracic Surgery; Postoperative Cognitive Complications
MeSH terms: Postoperative Cognitive Complications
Study type: Observational

Summary: 
      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: 
      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
    

Intervention name(s): Sevoflurane; Propofol
Intervention type(s): Drug; Drug
Intervention description(s): 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; 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
Other intervention name(s): Remifentanil
Intervention MeSH terms: Remifentanil; Propofol; Sevoflurane
Observational model: Case-Control
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        Patients who would undergo thoracic surgery with one-lung ventilation (OLV)
      
Keywords: One-lung ventilation; cerebral oxygenation; postoperative cognitive dysfunction; sevoflurane; propofol