An Open Labelled Randomized Controlled Trial to compare the effect of Desflurane and Target Controlled Infusion of Propofol on Optic Nerve Sheath Diameter in patients undergoing Laparoscopic Procedures

Laparoscopic surgery is rapidly growing alternative technique to conventional open surgery for many types of surgical procedures because of it’s minimum blood loss, minimal invasiveness, less post operative pain and a consequent earlier discharge.

Despite many advantages of laparoscopic procedures the disadvantages of elevated intracranial pressure (ICP) and intra ocular pressure (IOP) remains which caused by steep angle of Trendelenberg position and the induced Co2 pneumoperitoneum.

Laparoscopy involves Co2 insufflation to create pneumoperitoneum for enhancement of operative visual field and often steep head-down position (up to 45 degree Trendelenberg position).

This Co2 gets absorbed in systemic circulation and arterial levels of Co2 increased. Co2 insufflation during pneumoperitoneum creation is associated with physiological changes resulting in a typical state of increased IOP during laparoscopic surgery.

There are various methods for detection of intracranial pressure both invasive and non invasive.

•       Invasive methods are costly require special precautions and strict neurological settings associated with serious complications like brain damage, hemorrhage, infection.

•       There are non invasive methods like cranial CT, MRI, USG. Amongst non invasive methods USG guided ONSD is the best.

Ultrasonographic measurement of the optic nerve sheath diameter (ONSD) is simple, non invasive, and accurate ICP assessment technique. Ultrasound of 6-15 Hz high frequency probe is used for ONSD measurement.

 AIM

To compare the effect of Desflurane and target controlled infusion of Propofol on optic nerve sheath diameter in patients  undergoing laproscopic surgeries

OBJECTIVES :

Primary Objective: To compare the effect of Desflurane and target controlled infusion of Propofol on optic nerve sheath diameter in patients  undergoing laproscopic surgeries.

Secondary Objective: To correlate the change in optic nerve sheath diameter with end tidal carbondioxide concentration (EtCo2)

METHODOLOGY

The patients will be informed about the study in a language they fully comprehend. The patient will be enrolled in the study after taking a written informed consent. A computer - generated table of random numbers will be used randomly to divide the patients into two groups : Patients that will receive inhalational anesthesia with Desflurane (Group I) and patients that will receive propofol- based TIVA (Group II) . After identification, On arrival into the operating room patient’s baseline parameters will be recorded. I.V Line to be secured. Glycopyrrolate (0.2mg) and midazolam (0.05mg/kg) will be administered before induction of anaesthesia in both groups.

In Group I patients, Patients  will be  oxygenated with 100% Oxygen for 3 minutes. General anaesthesia is induced with 1.5mg/kg propofol , 2mcg/kg fentanyl  and muscle relaxation will be achieved with IV atracurium 0.5mg/kg. Following tracheal intubation, anaesthesia will be maintained  with Desflurane. The end –tidal concentration of desflurane will be maintained  within the range of 4%-7%. In Group II patients, after tracheal intubation, anesthesia will be maintained with Propofol through Target Controlled Infusion (TCI) system. Patient’s ONSD will be measured in both eyes using 7.5 MHz Linear Ultrasound probe. ONSD will be measured  after induction (T0), 10 min after insufflation (Ti), 1st Hour, 2nd Hour, 3rd Hour, 4th Hour (T1, T2, T3, T4 respectively). Final reading will be taken after desufflation. Respiratory parameters (Peak airway pressure, End- tidal CO2) along with ONSD.