Matsuura Y, Kamidaira M, Tamura A (2018) Risk Factors for Postoperative Delirium after Cardiac Surgery. Int Arch Nurs Health Care 4:103.


© 2018 Matsuura Y, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

ORIGINAL ARTICLE | OPEN ACCESS DOI: 10.23937/2469-5823/1510103

Risk Factors for Postoperative Delirium after Cardiac Surgery

Yutaka Matsuura*, Mitsuki Kamidaira and Akiko Tamura

Department of Intensive Care Unit, Rinku General Medical Center, Japan



Postoperative delirium affects prognosis and the probability of survival. It is important for medical professionals to predict and prevent delirium, as well as implement appropriate interventions, early in the course of care. This study sought to reveal the risk factors for postoperative delirium based on general characteristics such as circulatory dynamics in patients admitted to the ICU after cardiac surgery.


Patients who underwent cardiac surgery were included in this study (n = 149). Trained nurses assessed postoperative delirium using the intensive care delirium screening checklist (ICDSC) from immediately after extubation to 2 days after extubation. Postoperative delirium was defined as the presence of at least four ICDSC items or diagnosed by a psychiatrist. Research variables were selected from preoperative, intraoperative, and postoperative factors. We performed univariate and multivariate logistic regression analysis using these variables.


Postoperative delirium developed in 40 patients (26.8%). Delirium was independently associated with a history of atrial fibrillation (odds ratio = 3.9109 [95% confidence interval = 1.3578-11.2643], p = 0.011), surgical time (1.0039 [1.0008-1.0069], p = 0.009), in/out balance during the surgery (1.0002 [1.0000-1.0004], p = 0.041), potassium levels immediately after surgery (0.3061 [0.1111-0.8435], p = 0.018), and systemic vascular resistance index immediately after extubation (1.0013 [1.0001-1.0025], p = 0.033).

Discussion & conclusion

Medical professionals, especially nurses, can potentially predict and prevent delirium by observing the identified risk factors.