Abstract: Objective To observe the effect of carbon dioxide pneumoperitoneum and Trendelenburg position on cerebral blood
backflow during robot-assisted radical prostatectomy in elderly patients. Methods Fifty elderly patients (65-80 years) and 50
middle-aged patients (45-64 years) undergoing elective robot-assisted prostatectomy were enrolled in this study. For all the
patients, jugular bulb and arterial blood gas was monitored and recorded before pneumoperitoneum (T0), 10 min after
pneumoperitoneum was achieved (T1), 10 min (T2) and 60 min (T3) after Trendelenberg position, and 10 min in supine position
after termination of pneumoperitoneum (T4). Results Compared with those at T0, the mean arterial pressure, heart rate, and
BIS value at T1, T2, T3 and T4 all showed no significant variations (P>0.05), but rSO2, SjvO2, and JBP increased significantly in
both groups (P<0.01). Compared with those in the middle-aged group, rSO2, SjvO2, and JBP increased significantly and Da-jO2
decreased at T2, T3 in the elderly group (P<0.01), but jugular vein blood glucose or lactic acid content showed no significant
difference between the two groups (P>0.05). Conclusion Pneumoperitoneum and Trendelenburg position cause more obvious
cerebral blood backflow in elderly patients than in middle-aged patients but do not affect cerebral metabolism of oxygen.