Incidence and risk factors of postoperative cognitive dysfunction in patients underwent coronary artery bypass grafting surgery

Abstract

To investigate the incidence rate and the risk factors for postoperative cognitive dysfunction (POCD) in patients underwent coronary artery bypass grafting surgery. A total of 147 patients underwent elective coronary artery bypass grafting (CABG) surgery between January to July 2013 were included in this study. POCD was diagnosed using a neuropsychological test battery. All enrolled patients were interviewed on the day before surgery, the seventh day and 3 months after surgery, respectively, by the same researcher, and were divided into two groups based on the results: the POCD group and the non-POCD group. The information, including age, sex, body mass index, educational status, comorbidities, history of smoking and drinking, ASA grade, left ventricular ejection fraction, operation method, duration of operations, regional cerebral oxygen saturation, the lowest haemoglobin concentrations and the haemoglobin concentration decline rate during the operation, tracheal catheter retention time, postoperative pain on visual analogue scales (VAS) and systemic inflammatory response syndrome score (SIRS score), were recorded based on a schedule of survey. Multivariate logistic regression was used to analyze the risk factors for POCD. A total of 101 patients finished this study. On 7 days and 3 months after surgery, 38 and 21 cases showed POCD, with an incidence rate at 37.6% and 20.8%, respectively. Interestingly, there was no significant difference in incidence of POCD between CABG and OPCABG group on both 7 days and 3 months after surgery (P>0.05). The logistic stepwise regression analysis indicated that the risk factors for POCD included advanced age (OR=1.177, 95%CI 1.071-1.292, P=0.001), the haemoglobin concentration decline rate (OR=1.334, 95%CI 1.152-1.545, P<0.05) and SIRS score (OR=2.815, 95%CI 1.014-7.818, P=0.047). The incidence rate of POCD was 37.6% and 20.8% on 7 days and 3 months after surgery respectively. Advanced age, the haemoglobin concentration decline rate and SIRS score are independent risk factors for POCD in patients underwent coronary artery bypass grafting surgery.