Preoperative testing programs and traditional systems of anesthesia evaluation do not routinely incorporate cognitive screening of the elderly patient into their preoperative assessments of vital organ systems. A paradigm shift will be necessary to make this screening routine and not just used as a research tool.1 The screening tool used must be robust, reproducible, and feasible. The prevalence of cognitive impairment without dementia is significant and increases with age, reported in about 22.2% of patients above 71 years of age.2 Without routine screening processes during preoperative assessment, undiagnosed cognitive impairment may be missed and therefore contribute to postoperative morbidity. The presence of impaired cognition before surgery is associated with higher 6-month and 1-year postoperative mortality rates and increased postdischarge institutionalization.3 , 4 Preoperative cognitive dysfunction is a risk factor for postoperative delirium, which is independently associated with increased hospital length of stay and overall cost.5
We describe our preliminary experience with developing a training program and implementing routine cognitive screening, sustainable stratification, and documentation in our preoperative clinic. We have previously found that cognitive screening with the Mini-Cog© examination is easy to administer, and there are data showing that healthcare practitioners can administer the Mini-Cog with high reliability after minimal training and practice.6 However, clinical feasibility and utility of screening in routine clinical practice warrant further study.7 Preoperative practitioners in routine clinical practice can be trained to effectively and efficiently incorporate routine cognitive stratification into a high-volume, high-acuity, tertiary care preoperative clinic population. The Figure describes implementation steps including choosing the type of cognitive examination, training nurse practitioners and anesthesia residents, implementation into daily visits, documentation in the electronic health record (EHR), cognitive stratification and assessment of screening results, and continuous process improvement.
Training Materials Development
Working with the geriatricians, we developed a 10-minute training video available through the hospital intranet, which provided education for accurately administering and scoring the Mini-Cog examination.8 The video included posttesting to ensure proficiency. All clinicians in our preoperative clinic were required to participate in this online learning module because they had no previous experience with administering this test. A sample of the testing results that had been scored by the clinical staff was evaluated by a geriatrician for accuracy. The geriatrician was blinded during the cross-checking of scores to prevent confirmation bias, and 92% accuracy of scoring was achieved. Once training of all clinical providers was complete, routine cognitive screening was begun.
Routine Cognitive Screening
Eligible patients included all those ≥65 years of age who were evaluated in the preoperative clinic at Brigham and Women’s Hospital during a 3-month period between March 2, 2015 and May 30, 2015. The evaluation consisted of surgical, anesthesia, and nursing assessments, which included cognitive screening. The nurse practitioners and residents who performed these assessments were supervised by an onsite attending anesthesiologist. All consecutive patients ≥65 years of age were asked to complete the testing, which was administered by the clinician performing their medical assessment. Patients were excluded from participating if they declined to participate in the testing, had a language barrier, and had visual or hearing impairments.
We chose the Mini-Cog examination that combines 2 cognitive tasks, a 3-item recall test for memory, and a clock-drawing test to assess spatial representation and serve as a distractor while assessing the patient’s recall capabilities. This test is administered over 3–4 minutes and has been validated in a variety of heterogeneous populations; poor performance on these tasks has been shown to correlate with similar stratification achieved on longer validated cognitive assessments.9 First, 3 unrelated words were presented for recall. The 3 words asked for recall in our study were “finger, river, and nation.” Using a preprinted circle, the patient was then instructed to put the numbers on the clock and draw the hands at 10 past 11. After 3 minutes, the patient was asked to recall the 3 stated words. The entire test was scored on a 5-point scale, where 1 point was awarded for each correct word recalled and 2 points for correct clock drawing. No points were awarded for abnormal clock drawing. A score of ≥3 was scored as a negative screen for cognitive impairment.10 The practitioner ensured that the examination was completed entirely by the patient without the help of the family. The examination (clock) was performed on paper and scored by the practitioner. The data were then entered into the patient’s EHR along with the rest of the preoperative clinical information.
In total, we trained 28 nurse practitioners and 50 anesthesia residents on how to correctly administer and score the Mini-Cog examination. Over the 3-month study period, a total of 1636 patients >65 years of age were seen in the clinic, with 1004 fully completing the cognitive testing. The percentage of patients with abnormal Mini-Cog stratification varied based on age. For example, abnormal result was present in 3.7% of those between 65–70 years of age, 27.4% of those between 81–85 years of age, and overall in 10% of patients tested during the study period (Table).
Implementation of routine preoperative cognitive screening is feasible, and clinical providers can be trained to successfully perform cognitive stratification examinations as part of routine preoperative evaluation. Our cognitive stratification results support other existing evidence that routine cognitive evaluation will reveal a significant number of patients without a previous diagnosis of dementia who have an abnormal cognitive screen.2 This examination has now become a routine part of our preoperative evaluation in patients ≥65 years of age. Now that we know we can successfully identify these patients, the next challenge is to establish a clinical pathway to improve their postoperative outcomes. There are obvious implications for these patients regarding ability to fully engage in the informed consent process and to understand preoperative directions, educational materials, and medication instructions. Our hope is that generating appropriate care algorithms for patients who stratify to an abnormal Mini-Cog would reduce the incidence of delirium.10 It is important to emphasize that the Mini-Cog is a test of cognitive stratification, and not a diagnostic test.11 Our preoperative clinic providers currently document the score as part of the neurological assessment in our EHR, where it can be easily reviewed by downstream providers such as anesthesiologists, surgeons, and geriatricians. Although we have not collected data on this, it is certainly possible that nurse practitioners in the preoperative clinic take extra care in explaining surgery-related instructions to these patients with abnormal Mini-Cog scores and their family members. Also, anesthesiologists, surgeons, and nurses caring for these patients with very low scores may think about care planning in a different way.
Effective preoperative cognitive screening should be routinely incorporated into the development of perioperative multidisciplinary geriatric care pathways, and we are collaborating with our geriatricians to create coordinated integrated pathways of care. We plan to reassess our screening program and include a wider patient population, including those who are non-English speakers and those with visual or hearing impairments. The American College of Surgeons and American Geriatric Society strongly recommend that preoperative clinicians assess the cognitive ability and capacity to understand the anticipated surgery, yet few institutions have initiated this practice.11 It is our hope that providing these pathways will result in less postoperative delirium and better overall postoperative outcomes, consistent with the goals of the American Society of Anesthesiologists Perioperative Brain Health Initiative.12
6. Long LS, Shapiro WA, Leung JM. A brief review of practical preoperative cognitive screening tools. Can J Anaesth. 2012;59:798–804.
9. Borson S, Scanlan JM, Chen P, Ganguli M. The Mini-Cog as a screen for dementia: validation in a population-based sample. J Am Geriatr Soc. 2003;51:1451–1454.
11. American College of Surgeons. ACS NSQIP®/AGS Best Practice Guidelines: Optimal Preoperative Assessment of the Geriatric Surgical Patient. Available at: https://www.facs.org/~/media/files/quality%20programs/nsqip/acsnsqipagsgeriatric2012guidelines.ashx. Accessed September 6, 2018.
12. Perioperative Brain Health Initiative. American Society of Anesthesiologists Perioperative Brain Health Initiative. Available at: https://www.asahq.org/brainhealthinitiative. Accessed July 27, 2018.