Comparison of supine vs trendelenburg position on optic nerve sheath diameter in laparoscopic surgery

Laparoscopic surgeries are widely used nowadays as an alternative over open surgeries for various procedures due to its minimal invasiveness, reduced hemorrhage risk, lower post operative pain and early discharge. However, in abdominal and laparoscopic surgeries, Trendelenburg position is often used for better surgical field exposure but postoperatively there are common incidences of delirium, cognitive dysfunction, conjunctival edema which can be attributed to increased intracranial pressure (ICP). This can result in acute rise in ICP which decreases cerebral perfusion pressure and can be deleterious increasing chances of morbidity and mortality. Thus, monitoring ICP during laparoscopic surgery might prevent such complications and enhance recovery.Thus, Optic nerve sheath diameter (ONSD) measurement with ultrasound has emerged as a simple, non-invasive and reliable surrogate of invasive ICP measurement. A prospective, randomized observational study will be conducted on a total of 40 adult patients planned for laparoscopic surgeries in trendelenburg position under general anaesthesia. The technique for general anaesthesia will be standardized in all patients. The ultrasonographic optic nerve sheath diameter measurements will be taken after 5 mins of induction in supine position and then in trendelenburg position after achieving adequate pneumoperitoneum and later after 5 mins of turning back to supine position post-surgery. Our aim of the study will be to quantitatively measure the ICP changes in supine and trendelenburg position using optic nerve sheath diameter changes in patients undergoing laparoscopic surgery and to assess effect of changing position from supine to trendelenburg position changes optic nerve sheath diameter. The primary outcome will be to measure the change in onsd on changing position from supine to trendelenburg position in elective laparoscopic surgeries as a surrogate marker for increased intracranial pressure. The secondary outcome will be the impact of duration of trendelenburg position in surgery on onsd patients undergoing elective laparoscopic surgeries and the impact of angle of trendelenburg position in surgery on onsd on changing position from supine to trendelenburg position undergoing elective laparoscopic surgeries.