Association Between Optic Nerve Head Blood Flow Measured Using Laser Speckle Flowgraphy and Radial Arterial Pressure During Aortic Arch Surgery.

OBJECTIVE: This study was designed to investigate the association between ocular blood flow measured using laser speckle flowgraphy (LSFG) and radial arterial pressure during aortic arch surgery. DESIGN: A prospective study. SETTING: A single university hospital. PARTICIPANTS: This study included 24 patients undergoing aortic arch surgery with cardiopulmonary bypass (CPB) using antegrade selective cerebral perfusion (SCP). INTERVENTIONS: Measurement of optic nerve head blood flow using LSFG and radial arterial pressure via a catheter in the radial artery METHODS AND MAIN RESULTS: Antegrade SCP was managed with 24℃ and 40-to-60 mmHg at the right radial artery, which usually corresponds to a flow rate of 10 mL/kg/min. Optic nerve head blood flow using LSFG and radial arterial blood pressure were evaluated simultaneously at the right side and recorded at the following 4 points: after the induction of anesthesia (phase 1), after the beginning of CPB (phase 2), after the beginning of antegrade SCP (phase 3), and after cessation of CPB (phase 4). A moderate positive correlation between %change of mean blur rate in the optic nerve head measured using LSFG and %change of radial mean arterial pressure was identified (r = 0.604, p < 0.001). Bland-Altman analysis showed that the bias (mean difference) was -1.2% (95% limits of agreement -47.4% to 45.0%), indicating good agreement between %changes of the values recorded using the 2 measurements. CONCLUSIONS: Intraoperative monitoring of optic nerve head blood flow using LSFG can be used as an additional cerebral perfusion parameter during aortic arch surgery with CPB using antegrade SCP.