Browne S M, Halligan P W, Wade D T, Taggart D P
Oxford Heart Centre, John Radcliffe Hospital, Oxford, United Kingdom.
J Thorac Cardiovasc Surg. 2003 Oct;126(4):1061-4. doi: 10.1016/s0022-5223(03)00616-0.
Cognitive dysfunction and postoperative hypoxia are common sequelae of coronary artery bypass grafting, but there has been no study to determine whether there is any relationship between them.
Arterial blood gas measurements were performed before surgical intervention and on the second and fifth postoperative day, and neuropsychological assessments were performed before surgical intervention and 5 days and 3 months postoperatively by using a battery of 10 psychometric tests in 175 patients undergoing coronary artery bypass grafting. An estimate of overall performance on the battery at each assessment point was provided by a simple aggregate cognitive index score calculated from the mean z scores of 4 normally distributed test variables. Multiple regression analysis was performed by using the cognitive index score at day 5 as the dependent variable, with age, sex, duration of the operation, presence or absence of cardiopulmonary bypass, preoperative cognitive index score, and arterial oxygenation and percentage of saturation at day 5 as independent variables.
The mean cognitive index score decreased significantly in 115 (66%) patients who agreed to neuropsychological test battery assessment on the fifth postoperative day but improved significantly beyond baseline at 3 months. Mean arterial oxygen tension and percentage of saturation decreased significantly 2 days after the operation and, although improving over the following 3 days, remained decreased at day 5. Decreased cognitive index scores at day 5 strongly predicted cognitive impairment at 3 months (r = 0.36). The only significant independent predictors of the day 5 cognitive index score in the multiple regression analysis were preoperative cognitive index score and arterial oxygenation tension at day 5 (r = 0.24, P <.03).
We report a significant correlation between postoperative cognitive dysfunction and hypoxia 5 days after coronary artery bypass grafting. This finding might have therapeutic implications because early postoperative cognitive dysfunction influences long-term impairment.
认知功能障碍和术后缺氧是冠状动脉旁路移植术常见的后遗症，但尚无研究确定它们之间是否存在关联。
对175例行冠状动脉旁路移植术的患者在手术干预前、术后第2天和第5天进行动脉血气测量，并在手术干预前、术后5天和3个月使用一组10项心理测量测试进行神经心理学评估。通过从4个正态分布测试变量的平均z分数计算得出的简单综合认知指数评分，对每个评估点的测试总体表现进行估计。以术后第5天的认知指数评分为因变量，年龄、性别、手术持续时间、是否进行体外循环、术前认知指数评分以及术后第5天的动脉氧合和饱和度百分比为自变量进行多元回归分析。
115例（66%）患者在术后第5天同意进行神经心理学测试组评估，其平均认知指数评分显著下降，但在3个月时显著改善至基线以上。术后2天平均动脉血氧分压和饱和度百分比显著下降，尽管在接下来的3天有所改善，但在第5天仍低于术前。术后第5天认知指数评分降低强烈预测3个月时的认知障碍（r = 0.36）。多元回归分析中，术后第5天认知指数评分的唯一显著独立预测因素是术前认知指数评分和术后第5天的动脉氧分压（r = 0.24，P <.03）。
我们报告了冠状动脉旁路移植术后5天认知功能障碍与缺氧之间存在显著相关性。这一发现可能具有治疗意义，因为术后早期认知功能障碍会影响长期损害。
