Postoperative Delirium Is Associated with Long-term Decline in Activities of Daily Living

Abstract

Background: Postoperative delirium is one of the most common complications in the elderly surgical population. However, its long-term outcomes remain largely to be determined. Therefore a prospective cohort study was conducted to determine the association between postoperative delirium and long-term decline in activities of daily living and postoperative mortality. The hypothesis in the present study was that postoperative delirium was associated with a greater decline in activities of daily living and higher mortality within 24 to 36 months after anesthesia and surgery.

Methods: The participants (at least 65 yr old) having the surgeries of (1) proximal femoral nail, (2) hip replacement, or (3) open reduction and internal fixation under general anesthesia were enrolled. The Confusion Assessment Method algorithm was administered to diagnose delirium before and on the first, second, and fourth days after the surgery. Activities of daily living were evaluated by using the Chinese version of the activities of daily living scale (range, 14 to 56 points), and preoperative cognitive function was assessed by using the Chinese Mini-Mental State Examination (range, 0 to 30 points). The follow-up assessments, including activities of daily living and mortality, were conducted between 24 and 36 months after anesthesia and surgery.

Results: Of 130 participants (80 ± 6 yr, 24% male), 34 (26%) developed postoperative delirium during the hospitalization. There were 32% of the participants who were lost to follow-up, resulting in 88 participants who were finally included in the data analysis. The participants with postoperative delirium had a greater decline in activities of daily living (16 ± 15 vs. 9 ± 15, P = 0.037) and higher 36-month mortality (8 of 28, 29% vs. 7 of 75, 9%; P = 0.009) as compared with the participants without postoperative delirium.

Conclusions: Postoperative delirium was associated with long-term detrimental outcomes, including greater decline in activities of daily living and a higher rate of postoperative mortality.

Figure 1.

Consort diagram shows the enrollment, exclusions, and participants available for analysis.

Figure 2.. Cumulative survival rates according to the presence of postoperative delirium.

The postoperative morality rates within 24–36 months of the followed participants after orthopedic surgery were calculated by using the Kaplan-Meyer analysis. Specifically, the 36-month mortality rate of participants with postoperative delirium (8/28, 29%) was significantly higher than that of participants without postoperative delirium (7/75, 9%) at the follow-up (P = 0.009, log-rank test). Symbols (+) indicate the censored data.