Investigation of the Effect of Cardiopulmonary Bypass on Optic Nerve Sheath Diameter

Objective: We sough to evaluate the effects of cardiopulmonary bypass (CPB) on the intracranial area using ultrasound-guided optic nerve sheath diameter (ONSD), a noninvasive and easy to use technique. Methods: We prospectively studied 67 patients aged 18–80. Ultrasound (USG) measured the ONSD of the patients, and the threshold ONSD was accepted as 5.5 mm. Patients were divided into two groups according to ONSD during CPB. Group 1: ONSD less than 5.5 mm, and Group 2: ONSD at or greater than 5.5 mm. Demographic data, comorbidities, intraoperative and postoperative findings, and complications were recorded. Results: There was no difference between the groups regarding demographic data and comorbidities (p > 0.05). The amount of fresh frozen plasma and erythrocyte suspension transfusions were statistically significantly higher in Group 2 (p < 0.05). Bleeding between the groups, intravenous fluid administered, and urine output were higher in Group 2 but was not statistically significant. There was no statistical difference in the mean extubation time, intensive care and hospital stay, and postoperative complications between the groups (p > 0.05). There was no mortality in Group 1, but two patients in Group 2 died. A statistically significant increase on ONSD was observed in Group 2 compared to Group 1 (p < 0.001). Conclusion: We observed that the increase in ONSD was greater in open heart surgeries that required increased blood and blood product transfusion. However, prospective studies are needed to investigate its clinical effects.