The Relationship Between Optic Nerve Sheath Diameter and Postoperative Delirium in Open Heart Surgery

Postoperative delirium is characterized by widespread brain involvement and its incidence is between 6% and 30%. It appears twice as often after cardiac and vascular surgery than other types of surgery. The correlation between optic nerve sheath diameter (ONSD) and invasive intracranial pressure measurement is excellent. ONSD reduction has the potential to indicate intracranial hypoperfusion causing delirium. In this observational study, patients aged 18 years and over who will undergo open heart surgery will be examined. ONSD will be measured using ultrasound five times in the perioperative period (t0: pre-induction, t1: post-induction, t2: onset of cardiopulmonary bypass (CPB), t3: post-CPB, and t4: post-ICU admission). The Confusion Assessment Method for the ICU (CAM-ICU) test will be used to examine delirium in the ICU. Whether the change in ONSD is an independent risk factor for delirium will be evaluated.