Price Catherine C, Garvan Cynthia, Hizel Loren P, Lopez Marcos G, Billings Frederic T
Clinical and Health Psychology, University of Florida, Gainesville, FL, USA.
Anesthesiology, University of Florida, Gainesville, FL, USA.
J Alzheimers Dis. 2017;59(3):1027-1035. doi: 10.3233/JAD-170380.
Reduced preoperative cognition is a risk factor for postoperative delirium. The significance for type of preoperative cognitive deficit, however, has yet to be explored and could provide important insights into mechanisms and prediction of delirium.
Our goal was to determine if certain cognitive domains from the general cognitive screener, the Mini-Mental State Exam (MMSE), predict delirium after cardiac surgery.
Patients completed a preoperative MMSE prior to undergoing elective cardiac surgery. Following surgery, delirium was assessed throughout ICU stay using the Confusion Assessment Method for ICU delirium and the Richmond Agitation and Sedation Scale.
Cardiac surgery patients who developed delirium (n = 137) had lower total MMSE scores than patients who did not develop delirium (n = 457). In particular, orientation to place, working memory, delayed recall, and language domain scores were lower. Of these, only the working memory and delayed recall domains predicted delirium in a regression model adjusting for history of chronic obstructive pulmonary disease, age, sex, and duration of cardiopulmonary bypass. For each word not recalled on the three-word delayed recall assessment, the odds of delirium increased by 50%. For each item missed on the working memory index, the odds of delirium increased by 36%. Of the patients who developed delirium, 47% had a primary impairment in memory, 21% in working memory, and 33% in both domains. The area under the receiver operating characteristics curve using only the working memory and delayed recall domains was 0.75, compared to 0.76 for total MMSE score.
Delirium risk is greater for individuals with reduced MMSE scores on the delayed recall and working memory domains. Research should address why patients with memory and executive vulnerabilities are more prone to postoperative delirium than those with other cognitive limitations.
术前认知功能减退是术后谵妄的一个危险因素。然而，术前认知缺陷类型的意义尚待探索，这可能为谵妄的机制和预测提供重要见解。
我们的目标是确定简易精神状态检查表（MMSE）这一通用认知筛查工具中的某些认知领域是否能预测心脏手术后的谵妄。
患者在接受择期心脏手术前完成术前MMSE检查。术后，在整个重症监护病房（ICU）住院期间，使用ICU谵妄的意识模糊评估方法和里士满躁动镇静量表对谵妄进行评估。
发生谵妄的心脏手术患者（n = 137）的MMSE总分低于未发生谵妄的患者（n = 457）。特别是，地点定向、工作记忆、延迟回忆和语言领域得分较低。其中，在调整了慢性阻塞性肺疾病史、年龄、性别和体外循环时间的回归模型中，只有工作记忆和延迟回忆领域能预测谵妄。在三字延迟回忆评估中，每一个未回忆起的单词，发生谵妄的几率增加50%。在工作记忆指数上每遗漏一项，发生谵妄的几率增加36%。在发生谵妄的患者中，47%主要存在记忆障碍，21%存在工作记忆障碍，33%在两个领域均有障碍。仅使用工作记忆和延迟回忆领域时，受试者工作特征曲线下面积为0.75，而MMSE总分的曲线下面积为0.76。
延迟回忆和工作记忆领域MMSE得分降低的个体发生谵妄的风险更高。研究应探讨为什么存在记忆和执行功能缺陷的患者比其他认知功能受限的患者更容易发生术后谵妄。
