Optic Nerve Sheath Diameter in Low-flow and Normal-flow Rate Anesthesia
Condition: Intracranial Hypertension
MeSH terms: Intracranial Hypertension
Study type: Interventional

Summary: 
      Laparoscopic cholecystectomy is one of the regularly performed laparoscopic surgical
      procedures. It resulted in shorter hospital stays, improved cosmetic outcomes, and reduced
      bleeding and pain. However, during laparoscopic surgeries, the pneumoperitoneum is known to
      raise intracranial pressure (ICP), reduction in cerebral blood flow (CBF), and as a
      consequence, cerebral hypoxia. There are various possible advantages of low-flow anesthesia.
      During laparoscopic procedures, low-flow anesthesia may be used as a means of preventing a
      rise in intracranial pressure and cerebral hypoxia. But low flow anesthesia effects on İCP
      are not known in Laparoscopic cholecystectomy. The primary aim of this study is to compare
      the effects of low-flow (0.75 l/min) and normal-flow (1.5 l/min) anesthesia on ONSD in
      patients undergoing laparoscopic cholecystectomy. Seconder aims are regional cerebral oxygen
      saturation (rSO2), bispectral index (BIS), and evaluate the status of cognitive function in
      the postoperative 24th hours.
    

Detailed description: 
      Laparoscopic cholecystectomy is one of the regularly performed laparoscopic surgical
      procedures. It resulted in shorter hospital stays, improved cosmetic outcomes, and reduced
      bleeding and pain. However, during laparoscopic surgeries, the pneumoperitoneum is known to
      raise intracranial pressure (ICP), reduction in cerebral blood flow (CBF), and as a
      consequence, cerebral hypoxia.

      Near-infrared spectroscopy (NIRS), a noninvasive and continuous measuring method used to
      evaluate the appropriateness of cerebral perfusion, is therefore utilized in conjunction with
      cerebral oximetry to quantify regional tissue oxygenation. On the other, BIS is the most
      reliable technique for determining the level of sedation and anesthesia. Patients experience
      fewer intraoperative wake-ups thanks to BIS monitoring. Increased intra-abdominal pressure,
      decreased cerebrospinal fluid (CSF) absorption and obstruction of lumbar venous plexus
      drainage, increased pressure in the sacral spaces' vascular compartment, and cerebral
      vasodilation brought on by hypercarbia are some of the suggested mechanisms for why ICP
      increases during laparoscopy. Intraventricular and intraparenchymal catheterization remains
      the gold standard for determining and monitoring ICP. However, due to worries about severe
      complications like bleeding, infection, and equipment failure, invasive ICP monitoring during
      laparoscopic surgery is almost impossible. Recently, ultrasound-guided optic nerve sheath
      diameter (ONSD) measurement is a simple and reliable method of predicting elevated ICP.

      There are various possible advantages of low-flow anesthesia. It boosts mucociliary
      clearance, preserves body temperature, lessens fluid loss, generates savings of up to 75%,
      and lowers greenhouse gas emissions as well as the cost of treatment. It also improves the
      flow dynamics of the breathed air. During laparoscopic procedures, low-flow anesthesia may be
      used as a means of preventing a rise in intracranial pressure and cerebral hypoxia. But low
      flow anesthesia effects on İCP are not known in Laparoscopic cholecystectomy.

      The primary aim of this study is to compare the effects of low-flow (0.75 l/min) and
      normal-flow (1.5 l/min) anesthesia on ONSD in patients undergoing laparoscopic
      cholecystectomy. Seconder aims are regional cerebral oxygen saturation (rSO2), bispectral
      index (BIS), and evaluate the status of cognitive function in the postoperative 24th hours.
    

Intervention name(s): Low flow technique in general anesthesia
Intervention type(s): Procedure
Intervention description(s): It will be used a low flow technique by giving airflow as 0.75 l/min after the intubation and will keep going on until the end of the laparoscopic cholecystectomy.
Intervention MeSH terms: Anesthetics
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Prevention
Keywords: Low flow anesthesia; optic sheath diameter; intracranial pressure; laparoscopic cholecystectomy