OBJECTIVETo observe the effect of carbon dioxide pneumoperitoneum and Trendelenburg position on cerebral blood backflow during robot-assisted radical prostatectomy in elderly patients.

METHODSFifty 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 (0), 10 min after pneumoperitoneum was achieved (T₁), 10 min (T₂) and 60 min (3) after Trendelenberg position, and 10 min in supine position after termination of pneumoperitoneum (4).

RESULTSCompared with those at 0, the mean arterial pressure, heart rate, and BIS value at 1, 2, 3 and 4 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-jO₂decreased at 2, 3 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).

CONCLUSIONPneumoperitoneum 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.