Prediction of Postoperative Delirium After Cardiac Surgery with A Quick Test of Cognitive Speed, Mini-Mental State Examination and Hospital Anxiety and Depression Scale

Abstract

Purpose To evaluate if preoperative assessment with A Quick Test of Cognitive Speed (AQT) could increase the accuracy of predicting delirium after cardiac surgery compared to Mini-Mental State Examination (MMSE), and examine if a composite of variables, including cognitive function and depressive symptoms, could be useful to predict delirium. Patients and Methods Cardiac surgery was performed in 218 patients (mean age 72 years). Preoperative evaluation involved AQT, MMSE and Hospital Anxiety And Depression Scale (HADS). Postoperative delirium was assessed using Nursing Delirium Screening Scale (Nu-DESC) and Confusion Assessment Method-ICU (CAM-ICU). Logistic regression was performed to detect predictors of postoperative delirium and receiver operator characteristic curves (ROC) with area under the curve (AUC) to determine the accuracy. Results Postoperative delirium occurred in 47 patients (22%) who had lower MMSE scores (median (range), 27 (19–30) vs 28 (20–30), p =0.009) and slower AQT (median (range), 76 (48–181) vs 70 (40–182) seconds, p =0.030) than patients without delirium. Predictive power measured as AUC (95% CI) was 0.605 (0.51–0.70) for AQT and 0.623 (0.53–0.72) for MMSE. Logistic regression (OR, 95% CI) showed MMSE <27 points (2.72, 1.27–5.86), AQT >70 sec (2.26, 1.03–4.95), HADS-D >4 points (2.60, 1.21–5.58) and longer cardiopulmonary bypass-time (1.007, 1.002–1.013) to be associated with postoperative delirium. Combining these parameters yielded an AUC of 0.736 (0.65–0.82). Conclusion The ability of predicting delirium using AQT was similar to MMSE, and only slightly higher by combining AQT and MMSE. Adding HADS-D and cardiopulmonary bypass-time to MMSE and AQT increased the predictive power to a borderline acceptable discriminatory value. Preoperative cognitive tests and screening for depressive symptoms may help identify patients at risk of postoperative delirium. Yet, there is still a need to establish useful preoperative tests.

The Age-adjusted Charlson Comorbidity Index predicts post-operative delirium in the elderly following thoracic and abdominal surgery: A prospective observational cohort study

“…Mini-Mental State Examination has been generally accepted as a simple scale to evaluate cognitive function, including 30 lists of decline symptoms totally, and lower scores represented worse cognitive condition in patients ( Segernäs et al, 2022 ). Our results showed that pre-operative MMSE scores in POD group were two points lower than those in non-POD group and were negatively associated with POD via multivariate regression analysis, which suggested that patients may have some impaired brain function pre-operatively, and thus increasing the probability to develop POD ( Pettemeridou et al, 2021 ).…”

“…Clinical data obtained from the electronic anesthesia record included operation and anesthesia time, surgical types, drugs usage (remifentanil and sufentanil), and others. Mini-Mental State Examination (MMSE) was adopted to assess the pre-operative cognitive condition, and MMSE score of less than 27 indicated cognitive impairment ( Segernäs et al, 2022 ). Anxiety or depression was diagnosed by Hospital Anxiety and Depression Scale (HADS) ( Pais-Ribeiro et al, 2018 ).…”

A novel predictive model for postoperative delirium using multiple geriatric screening factors

“…However, MMSE scores can be influenced by education, age, language, and ethnicity, with concerns also about limitations in identifying patients with mild cognitive impairment 7–9 . In addition, to the best of our knowledge, no reports exist of MMSE being highly predictive (performance exceeding 0.8 in the area under the receiver operating characteristic curve [AUC]) for POD 5,10 …”

The association of depression and postoperative delirium: we may need more information

“…Delirium is an acute organ dysfunction with mental status changes including alterations in level of consciousness, known to burden postoperative outcomes [ 2 ] and investigated in patients undergoing non-cardiac [ 3 ] and cardiac surgery [ 4 ]. Preoperative cognitive status and depression have been associated with postoperative delirium (POD).…”

“…Preoperative cognitive status and depression have been associated with postoperative delirium (POD). Assessment scores can be influenced by age, education or ethnicity [ 4 ]. Some strategies are currently being investigated aiming at predicting and treating POD after in different settings [ 5 , 6 ].…”