Delirium Severity Post-Surgery and its Relationship with Long-Term Cognitive Decline in a Cohort of Patients without Dementia

Article type: Research Article

Authors: Vasunilashorn, Sarinnapha M.^{a; b; 1; *} | Fong, Tamara G.^{b; c; d; 1} | Albuquerque, Asha^d | Marcantonio, Edward R.^{a; b; e} | Schmitt, Eva M.^d | Tommet, Douglas^f | Gou, Yun^d | Travison, Thomas G.^{b; d; e} | Jones, Richard N.^{f; 2} | Inouye, Sharon K.^{b; d; e; 2}

Affiliations: [a] Department of Medicine, Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center, Boston, MA, USA | [b] Harvard Medical School, Boston, MA, USA | [c] Department of Neurology, Beth Israel Deaconess Medical Center, Boston, MA, USA | [d] Aging Brain Center, Institute for Aging Research, Hebrew SeniorLife, Boston, MA, USA | [e] Department of Medicine, Division of Gerontology, Beth Israel Deaconess Medical Center, Boston, MA, USA | [f] Departments of Psychiatry and Human Behavior and Neurology, Warren Alpert Medical School, Brown University, Boston, MA, USA

Correspondence: [*] Correspondence to: Sarinnapha M. Vasunilashorn, PhD, Beth Israel Deaconess Medical Center, General Med/CO-1309 –2nd Floor, 330 Brookline Avenue, Boston, MA 02215, USA. Tel.: +1 617 754 1417; Fax: +1 617 754 1440; E-mail: [email protected].

Note: [1] These authors contributed equally to this work.

Note: [2] Co-senior authors.

Abstract: Background:Delirium has been associated with more rapid cognitive decline. However, it is unknown whether increased delirium severity is associated with a higher rate of long-term cognitive decline. Objective:To evaluate delirium severity and the presence and rate of cognitive decline over 36 months following surgery. Methods:We examined patients from the Successful Aging after Elective Surgery Study, who were age ≥70 years undergoing major elective surgery (N = 560). Delirium severity was determined by the peak Confusion Assessment Method-Severity (CAM-S) score for each patient’s hospitalization and grouped based on the sample distribution: scores of 0–2, 3–7, and 8–19. A neuropsychological composite, General Cognitive Performance (GCP), and proxy-reported Informant Questionnaire for Cognitive Decline (IQCODE) were used to examine cognitive outcomes following surgery at 0, 1, and 2 months, and then every 6 months for up to 3 years. Results:No significant cognitive decline was observed for patients with peak CAM-S scores 0–2 (–0.17 GCP units/year, 95% confidence interval [CI] –0.35, 0.01). GCP scores decreased significantly in the group with peak CAM-S scores 3–7 (–0.30 GCP units/year, 95% CI –0.51, –0.09), and decreased almost three times faster in the highest delirium severity group (peak CAM-S scores 8–19; –0.82 GCP units/year, 95% CI –1.28, –0.37). A similar association was found for delirium severity and the proportion of patients who developed IQCODE impairment over time. Conclusion:Patients with the highest delirium severity experienced the greatest rate of cognitive decline, which exceeds the rate previously observed for patients with dementia, on serial neuropsychological testing administered over 3 years, with a dose-response relationship between delirium severity and long-term cognitive decline.

Keywords: Aged, cognition, delirium, dementia

DOI: 10.3233/JAD-170288

Journal: Journal of Alzheimer's Disease, vol. 61, no. 1, pp. 347-358, 2018