Optic Nerve Sheath Diameter Evaluation as a Predictor of Brain Edema in Hyperglycemic Acute Complications of Diabetes Mellitus in Adult Critically Ill Patients

Background: Cerebral edema, a severe complication of hyperglycemia in critically ill diabetic patients, requires rapid diagnosis and treatment. Ocular ultrasonography (USG) has been widely used to measure optic nerve sheath diameter (ONSD) for detecting increased intracranial pressure (ICP) in various cranial events. This study aimed to compare ONSD measurements before and after treatment in patients with acute hyperglycemic complications. Methods: This prospective cohort study included 66 patients, divided into three equal groups: Group D (DKA) with random blood sugar ⩾250 mg/dL, pH ⩽7.30, bicarbonate ⩽15 mEq/L, and ketonuria; Group H (HHS) with random blood sugar ⩾600 mg/dL, pH >7.30, bicarbonate >15 mEq/L, osmolarity >315 mOsm/kg, and no ketonuria; and Group I (isolated hyperglycemia) with random blood sugar ⩾250 mg/dL but not meeting DKA or HHS criteria. Results: The right and left ONSD were statistically significantly different among the studied groups at all measurement times (0, 2, 8, and 24h). In DKA and HHS groups, ONSD significantly decreased after 2 hours, suggesting improvement. However, in isolated hyperglycemia, ONSD was insignificantly different among the different measurements. Conclusions: ONSD is a valuable non-invasive tool for diagnosing and monitoring acute hyperglycemic complications in diabetic patients and can be used as a predictor of brain edema in adult critically ill patients.