Sauer AC, et al. – The link between postoperative delirium (POD) and cognitive alterations following cardiac surgery was explored in this present study. Researchers also assessed the association between preoperative cognitive domain scores and POD. Findings demonstrated an independent association of postoperative delirium with cognitive decline 1 month post operation, but cognitive performance generally recovered in 1 yr. In addition, it was noted patients with a predisposition to POD could be identified before surgery by worse performance in an attention task.

Methods

• Researchers examined postoperative delirium with the Confusion Assessment Method (CAM) adapted for the intensive care unit and the conventional CAM accompanied by chart review.
• They also assessed cognitive function with a neuropsychological test battery before elective cardiac surgery and 1 month and 1 yr afterwards.
• Thereafter, they calculated cognitive change using the Reliable Change Index (RCI).
• They also used multiple linear regression to adjust for confounding.

Results

• Findings showed that out of the 184 patients who completed baseline assessment, 23 (12.5%) developed POD.
• Researchers found that at 1 month, the decline in cognitive performance was worse in patients with POD [median composite RCI -1.00, interquartile range (IQR) -1.67 to 0.28] than in patients without POD (RCI -0.04, IQR -0.70 to 0.63, P=0.02).
• They also noted that at 1 yr, both groups showed cognitive improvement on average compared with baseline (POD patients median composite RCI 0.25, IQR -0.42 to 1.31, vs non-POD patients RCI 0.92, IQR 0.18–1.53; P=0.08).
• Data also highlighted that correction for differences in age and level of education did not change the results.
• In addition, it was shown that patients with POD performed less well than patients without POD on the preoperative Trailmaking test part A (P=0.03).