RESUMO
Objective To investigate the risk factors for postoperative cognitive dysfunction (POCD)induced by patient-controlled intravenous analgesia(PCIA)in elderly patients. Methods 95 patients with POCD and 97 cognitive normal controls were included in the study. The cases and controls were matched for gender, type of operation and PCIA volume dose. Cognitive function was assessed by Mini-Mental-State test and the relationship between POCD and various factors was analyzed by univariate and multivariate analysis. Results Univariate analysis revealed that the education level and visual analog scale (VAS) score had significant differences between the two groups. Multivariate analysis showed that the VAS score and education level were significantly related to POCD induced by PCIA, with the odds ratios of 2. 379 (95%CI:1.205～4.698) and 0. 292 (95%CI:0.157～0.543), respectively. Conclusions Lower VAS score is an independent risk factor and higher education level seems to be a protective factor for POCD induced by PCIA.