Effect of Hypotensive Anesthesia on Cerebral Perfusion and Blood Antioxidant Levels and HIF 1a
Condition: Hypoxemia During Surgery; Hypoxia, Brain
MeSH terms: Hypoxia, Brain; Hypoxia
Study type: Interventional

Summary: 
      The aim of this study to evaluate the patients who underwent controlled hypotensive
      anesthesia under standardized depth of anesthesia; preoperative and postoperative blood HIF
      1a, TAS, TOS measurement and cerebral perfusion evaluation with NIRS and to investigate
      tissue hypoxia secondary to hypotensive anesthesia and the changes of the mediators at the
      tissue level and which blood pressure parameters are related.
    

Detailed description: 
      Controlled hypotension is the voluntary reversible reduction of arterial blood pressure.
      Hypotensive anesthesia is a method of anesthesia in which blood pressure is reduced in a
      controlled manner, especially in certain surgeries. İt reduces intraoperative bleeding and
      need for blood transfusion and provides a clean surgical vision in narrow-field surgeries or
      with high bleeding potential. Hypotensive anesthesia can be performed according to mean blood
      pressure (MBP) or systolic blood pressure (SBP).

      A non-invasive cerebral oximeter is used to see the changes in the brain due to high
      oxygen-dependent metabolism during induction and maintenance of anesthesia.

      Hypoxia inducible factor (HIF) is a transcription factor involved in cell adaptation
      mechanism activated in response to hypoxia.

      The biological activity of HIF 1 is determined by the expression and activity of the HIF 1a
      subunit.

      Total antioxidant status (TAS) shows the total effect of all antioxidants in the human body
      and total oxidant status (TOS) shows the total effect of oxidants.

      Near Infrared Spectroscopy (NIRS) allows continuous and non-invasive monitoring of cerebral
      oxygenation. HIF 1a, TAS and TOS are laboratory markers that predict tissue oxygenation and
      perfusion.

      Hypotensive anesthesia can be performed according to both MBP and SBP. However, in our study
      that follow-up MBP is more advantageous/protective, although it is not supported by very
      strong data. The investigators recommend hypotensive anesthesia compared to MBP; but further
      studies are needed.
    

Intervention name(s): systolic blood pressure (SBP); mean blood pressure (MBP)
Intervention type(s): Procedure; Procedure
Intervention description(s): Systolic blood pressure (SBP) 80-90 mmHg remifentanil infusion was applied to Group 1 patients. In addition to remifentanil infusion, 0.002 μg.kg of glycerol trinitrate (Perlinganit) was administered as an intermittent bolus in patients who needed to achieve target blood pressure. All patients received 5-8 ml / kg / h IV infusion of balanced electrolyte solution (Isolyte-S) during the operation.
Hemodynamic parameters (HR, SBP, OCD), BIS, SpO2 and NIRS were recorded at 5 minute intervals. At the end of the operation, 3 ml of blood was taken from the untreated arm of all patients to the HIF1a, TAS and TOS values and sent to the biochemistry laboratory; For group 2, remifentanil infusion was performed with a mean blood pressure (OCD) of 50-65 mmHg. In addition to remifentanil infusion, 0.002 μg.kg of glycerol trinitrate (Perlinganit) was administered as an intermittent bolus in patients who needed to achieve target blood pressure. All patients received 5-8 ml / kg / h IV infusion of balanced electrolyte solution (Isolyte-S) during the operation.
Hemodynamic parameters (HR, SBP, OCD), BIS, SpO2 and NIRS were recorded at 5 minute intervals. At the end of the operation, 3 ml of blood was taken from the untreated arm of all patients to the HIF1a, TAS and TOS values and sent to the biochemistry laboratory.
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: A total of 60 ASA 1-2 patients aged between 18-75 who underwent elective rhinoplasty and orthognathic surgery were included the study.The patients were divided into two groups. One group received hypotensive anesthesia according to MBP an done group received SBP. Continuous regional cerebral oxygen saturation was monitored by NIRS in both groups. Blood samples were taken from all patients before anesthesia induction and at the and of the operation and stored for TAS, TOS, HIF 1a. At the and of the operation patients were fallowed in the post anesthesia care unit for 30 minutes and pain and nause vomiting scores were evaluated. İn addition, surgical satisfaction and bleeding scores and anesthetic consumption of both groups were recorded
Masking: Single (Participant)
Primary purpose: Screening
Keywords: hypotensive anesthesia; HIF 1a; Brain Hypoxia; tissue hypoxia