Effects of Dexamethasone on Cognitive Functions After Coronary Artery Bypass Grafting Surgery

TL;DR

This study found that dexamethasone may help protect cognitive functions like attention and spatial ability after heart surgery, but the overall effect was not statistically significant.

Contribution

The study provides new evidence on the potential neuroprotective effects of dexamethasone in CABG surgery patients.

Findings

Dexamethasone improved attention, fluency, and spatial ability post-surgery.

Cognitive impairment was lower in the dexamethasone group (40%) compared to the non-DEXA group (69.3%).

No significant difference was found in language and memory scores between the groups.

Abstract

Background and Objectives: Coronary artery bypass grafting (CABG) is one of the most common cardiac surgeries worldwide. However, postoperative cognitive decline (POCD) remains a significant concern, affecting a substantial proportion of patients. One of the pathogenic mechanisms underlying POCD involves inflammatory responses and oxidative stress. Dexamethasone, a corticosteroid with potent anti-inflammatory properties, has been proposed as a potential neuroprotective agent. This study aimed to assess the effect of a single perioperative dose of dexamethasone on postoperative cognitive function in patients undergoing CABG surgery. Materials and Methods: This retrospective cohort study was conducted at the Hospital of Lithuania. Inclusion criteria: elective CABG surgery, non-neurocognitive anamnesis, Minimal Mental State Examination score ≥25 before surgery, and age >50. Patients were divided into two groups: DEXA (those who received preoperative dexamethasone 0.1 mg/kg) and non-DEXA (those who did not). Cognitive functions were assessed with the Addenbrooke’s Cognitive Examination test (ACE-III) 7 days post operation. Results: The study enrolled 60 patients (DEXA = 30, non-DEXA = 30): male (85%), female (15%). The mean age of the study was 66.1 ± 8.1 and the education was 12 (12–30) years. The groups were similar in the evaluated preoperative characteristics (sex, age, education) (p > 0.05). Cognitive impairment (ACE-III score cut–off 88 points) was identified in 40% (n = 12) of participants in the DEXA and 69.3% (n = 21) in the non-DEXA group, with no statistically significant difference between groups (p = 0.073). However, the DEXA group had significantly better cognitive scores in attention (Z = 3.145, p = 0.002), fluency (Z = 2.25, p = 0.024), and spatial ability (Z = 4.444, p < 0.001) while language (Z = 1.167, p = 0.243) and memory scores (Z = 1.906, p = 0.057) showed no significant differences. Conclusions: These findings suggest that dexamethasone may provide neuroprotective benefit, reducing postoperative cognitive function domains, such as attention, fluency, and spatial ability, after CABG surgery. Further prospective studies are needed to confirm these findings.

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