Related Experiment Video
Updated: Mar 30, 2026
SECONDs Administration Guidelines: A Fast Tool to Assess Consciousness in Brain-injured Patients
Published on: February 6, 2021
Validation of the confusion assessment method in detecting postoperative delirium in cardiac surgery patients
Nina Smulter1, Helena Claesson Lingehall2, Yngve Gustafson2
1Nina Smulter is a registered nurse and lecturer, Department of Nursing and Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division Umeå University, Umeå, Sweden. Helena Claesson Lingehall is a registered nurse and doctoral student at Department of Nursing, Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division, Umeå University, and a nurse anesthetist in the Heart Center, University Hospital of Umeå, Västerbotten, Sweden. Yngve Gustafson is a professor, Department of Community Medicine and Rehabilitation, Geriatric Medicine, Umeå University. Birgitta Olofsson is an associate professor, Department of Nursing, Umeå University. Karl Gunnar Engström is a professor, Department of Surgical and Perioperative Science, Cardiothoracic Surgery Division, Umeå University. nina.smulter@umu.se.
Background:
Early detection, prevention, and treatment of delirium after cardiac surgery are important for quick postoperative recovery. The Confusion Assessment Method (CAM) may be an easy-to-use instrument for detecting delirium in clinical practice.
Objectives:
To compare the congruent validity of the CAM with the results from repeated assessments by using a combination of the Organic Brain Syndrome Scale and the Mini-Mental State Examination according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition, Text Revision) criteria for delirium.
Methods:
Patients aged 70 years or older undergoing cardiac surgery were assessed on postoperative days 1 and 4, and the 2 diagnostic methods were compared. The sensitivity and specificity of the CAM were examined. The reference method allowed categorization of delirium into subgroups of psychomotor activities and psychiatric symptom profiles, which were compared with the CAM results.
Results:
Postoperative delirium was diagnosed in 78 of 141 patients (55.3%). According to the CAM, 59 patients (41.8%) were categorized as delirious, 53 correctly. Thus, the sensitivity was 68% and the specificity was 90%, indicating false-negative rather than false-positive observations.
Conclusion:
Patients with psychomotor hyperactivity and mixed psychotic-emotional symptoms were more likely to have delirium detected via the CAM than were patients with less obvious clinical manifestations of delirium. Repetitive cognitive testing and psychogeriatric experience are probably necessary to improve the results obtained with the CAM.
