The correlation between the confusion assessment method for intensive care units 7-item, the intensive care delirium screening checklist and adverse outcomes after post-cardiac surgery delirium

Abstract Background Postoperative Delirium(POD) and Subsyndromal Delirium(SSD) remain prevalent, particularly among the cardiovascular surgical population due to the utilization of cardiopulmonary bypass. Adverse outcomes, such as prolonged ICU stay, extended length of stay, and increased incidence of adverse events, are associated with individuals diagnosed with Postoperative Delirium or those experiencing fluctuations between Postoperative Delirium and Subsyndromal Delirium during ICU stays. Therefore, early delirium screening is of utmost importance. The Intensive Care Delirium Screening Checklist(ICDSC) and the Confusion Assessment Method for the Intensive Care Unit 7-item(CAM-ICU-7) are validated delirium screening instruments for critical patients. Purpose This study aims to determine whether the ICDSC or the CAM-ICU-7 is the superior predictor for adverse outcomes following Postoperative Delirium among the cardiovascular population. Methods In this prospective cohort study, 84 patients who underwent elective cardiovascular surgery underwent a total of 833 paired assessments(ICDSC and CAM-ICU-7) twice daily by the researcher. The correlation between the results of ICDSC and CAM-ICU-7 was evaluated. Multiple linear regression was employed to explore associations between ICDSC and CAM-ICU-7 and length of ICU stay, length of overall stay, and the total number of adverse events. The best model was selected after testing with Pearson's correlation coefficient, Hotelling's t, and Steiger's Z tests. Logistic regression explored associations between ICDSC and CAM-ICU-7 and adverse events. Results Postoperative Delirium incidence evaluated by the ICDSC and CAM-ICU-7 was 47.61% and 45.23%, respectively. The incidence of fluctuations between Postoperative Delirium and Subsyndromal Delirium evaluated by the ICDSC and CAM-ICU-7 was 34.52% and 21.43%, respectively. The agreement between the ICDSC and CAM-ICU-7 is high(kappa = 0.835, p<0.001) in detecting Postoperative Delirium but fair in detecting Subsyndromal Delirium(kappa = 0.213, p<0.001). Our research revealed that the length of ICU stay can be predicted by POD(detected by ICDSC and CAM-ICU-7) and fluctuated POD and SSD(detected by ICDSC but not CAM-ICU-7). However, only fluctuated POD and SSD detected by ICDSC could predict hospital length of stay. The total number of adverse events and incidence could be predicted by POD either detected by ICDSC or CAM-ICU-7 but only fluctuated POD and SSD detected by ICDSC, not CAM-ICU-7, could predict the total number of adverse events. Conclusions Both ICDSC and CAM-ICU-7 can detect Postoperative Delirium with high agreement. However, ICDSC could identify more individuals with both Postoperative Delirium and Subsyndromal Delirium, thus predicting more adverse outcomes than CAM-ICU-7. Therefore, ICDSC emerges as the superior delirium screening instrument for the cardiovascular population.