Center for Quality Aging, Vanderbilt University School of Medicine, Nashville, TN; Department of Emergency Medicine, Vanderbilt University School of Medicine, Nashville, TN.
Acad Emerg Med. 2014 Feb;21(2):180-7. doi: 10.1111/acem.12309.
In the emergency department (ED), health care providers miss delirium approximately 75% of the time, because they do not routinely screen for this syndrome. The Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) is a brief (<1 minute) delirium assessment that may be feasible for use in the ED. The study objective was to determine its validity and reliability in older ED patients.
In this prospective observational cohort study, patients aged 65 years or older were enrolled at an academic, tertiary care ED from July 2009 to February 2012. An emergency physician (EP) and research assistants (RAs) performed the CAM-ICU. The reference standard for delirium was a comprehensive (~30 minutes) psychiatrist assessment using the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision criteria. All assessments were blinded to each other and were conducted within 3 hours. Sensitivities, specificities, and likelihood ratios were calculated for both the EP and the RAs using the psychiatrist's assessment as the reference standard. Kappa values between the EP and RAs were also calculated to measure reliability.
Of 406 patients enrolled, 50 (12.3%) had delirium. The median age was 73.5 years old (interquartile range [IQR] = 69 to 80 years), 202 (49.8%) were female, and 57 (14.0%) were nonwhite. The CAM-ICU's sensitivities were 72.0% (95% confidence interval [CI] = 58.3% to 82.5%) and 68.0% (95% CI = 54.2% to 79.2%) in the EP and RAs, respectively. The CAM-ICU's specificity was 98.6% (95% CI = 96.8% to 99.4%) for both raters. The negative likelihood ratios (LR-) were 0.28 (95% CI = 0.18 to 0.44) and 0.32 (95% CI = 0.22 to 0.49) in the EP and RAs, respectively. The positive likelihood ratios (LR+) were 51.3 (95% CI = 21.1 to 124.5) and 48.4 (95% CI = 19.9 to 118.0), respectively. The kappa between the EP and RAs was 0.92 (95% CI = 0.85 to 0.98), indicating excellent interobserver reliability.
In older ED patients, the CAM-ICU is highly specific, and a positive test is nearly diagnostic for delirium when used by both the EP and RAs. However, the CAM-ICU's sensitivity was modest, and a negative test decreased the likelihood of delirium by a small amount. The consequences of a false-negative CAM-ICU are unknown and deserve further study.
在急诊科 (ED)，医护人员大约有 75%的时间会错过谵妄，因为他们没有常规筛查这种综合征。《重症监护病房谵妄评估方法》（CAM-ICU）是一种简短（<1 分钟）的谵妄评估方法，可能适用于 ED。本研究的目的是确定其在老年 ED 患者中的有效性和可靠性。
在这项前瞻性观察队列研究中，2009 年 7 月至 2012 年 2 月，在一家学术性三级护理 ED 招募了 65 岁或以上的患者。急诊医师 (EP) 和研究助理 (RA) 进行了 CAM-ICU 评估。谵妄的参考标准是使用《精神障碍诊断与统计手册》第四版修订版标准进行全面 (~30 分钟) 精神科评估。所有评估均相互盲法进行，且在 3 小时内完成。使用精神病医生的评估作为参考标准，计算 EP 和 RA 的敏感度、特异度和阳性似然比。EP 和 RA 之间的 kapp 值也用于衡量可靠性。
在纳入的 406 名患者中，有 50 名 (12.3%) 患有谵妄。中位年龄为 73.5 岁 (四分位距 [IQR] = 69 至 80 岁)，202 名 (49.8%) 为女性，57 名 (14.0%) 为非白人。CAM-ICU 的敏感度分别为 EP 和 RA 的 72.0% (95%置信区间 [CI] = 58.3%至 82.5%) 和 68.0% (95% CI = 54.2%至 79.2%)。CAM-ICU 的特异性对于两个评估者均为 98.6% (95% CI = 96.8%至 99.4%)。阴性似然比 (LR-) 分别为 EP 和 RA 的 0.28 (95% CI = 0.18 至 0.44) 和 0.32 (95% CI = 0.22 至 0.49)。阳性似然比 (LR+) 分别为 EP 和 RA 的 51.3 (95% CI = 21.1 至 124.5) 和 48.4 (95% CI = 19.9 至 118.0)。EP 和 RA 之间的 kapp 值为 0.92 (95% CI = 0.85 至 0.98)，表明观察者间具有极好的可靠性。
在老年 ED 患者中，CAM-ICU 具有高度的特异性，当 EP 和 RA 均使用时，阳性试验几乎可以确诊谵妄。然而，CAM-ICU 的敏感度适中，阴性试验可少量降低谵妄的可能性。假阴性 CAM-ICU 的后果尚不清楚，值得进一步研究。
