Relationship between post-operative cognitive dysfunction and regional cerebral oxygen saturation and β-amyloid protein

Objective: To investigate the relationship between post-operative cognitive dysfunction (POCD) and regional cerebral oxygen saturation (rSO(2)) and beta-amyloid protein (A beta) in patients undergoing laparoscopic pancreaticoduodenectomy. Methods: Fifty patients undergoing elective laparoscopic pancreaticoduodenectomy received five groups of neuropsychological tests 1 d pre-operatively and 7 d post-operatively, with continuous monitoring of rSO(2) intra-operatively. Before anesthesia induction (t(0)), at the beginning of laparoscopy (t(1)), and at the time of pneumoperitoneum 120 min (t(2)), pneumoperitoneum 240 min (t(3)), pneumoperitoneum 480 min (t(4)), the end of pneumoperitoneum (t(5)), and 24 h after surgery, jugular venous blood was drawn respectively for the measurement of A beta by enzyme-linked immunosorbent assay (ELISA). Results: Twenty-one cases of the fifty patients suffered from POCD after operation. We found that the maximum percentage drop in rSO(2) (rSO(2), % max) was significantly higher in the POCD group than in the non-POCD group. The rSO(2), % max value of over 10.2% might be a potential predictor of neurocognitive injury for those patients. In the POCD group, the plasma A beta levels after 24 h were significantly higher than those of pre-operative values (P<0.01). After 24 h, levels of plasma A beta in the POCD group were significantly higher than those in the non-POCD group (P<0.01). Conclusions: The development of POCD in patients undergoing laparoscopic pancreaticoduodenectomy is associated with alterations of rSO(2) and A beta. Monitoring of rSO(2) might be useful in the prediction of POCD, and A beta might be used as a sensitive biochemical marker to predict the occurrence of POCD.