Post-operative delirium in older patients following cancer related and other high-risk surgeries.

Abstract

e24024 Background: Older adults are at increased risk for postoperative delirium (POD). This risk might be higher in patients with cancer as underlying malignancy and its complications predispose individuals to develop delirium. Therefore, it is important to evaluate the onset of delirium in this patient population especially as POD is associated with increased risk of rehospitalization, decline in cognitive function, morbidity and mortality. Methods: We performed a retrospective review of patients aged ≥ 70 years admitted January 2017 through July 2019 to a tertiary care referral center for a high-risk surgery, defined as associated with a mortality risk greater than 1%. Cancer related surgeries (CRS) were identified through cross matching with Cancer Registry. Patients who had delirium assessment in the postoperative setting using the Confusion Assessment Method (CAM) were included. Chi-square tests of proportion, Wilcoxon Ranked Sum and multivariate logistic regression analyses were conducted. Results: A total of 2340 patients were included in this analysis, 315 of whom had (CRS). Overall, the age (median, IQR) of patients at surgery was 76 years (72-80) and the length of stay (LOS) was 7 (4-11) days. Patients receiving CRS were younger (75, 72-79) than those with non-CRS (76, 72-81) (p = 0.022); had a shorter post-operative LOS (4, 2-7 vs. 5, 3-8; p > 0.001), and were less likely to develop POD (7.6% vs. 16.1%; p < 0.001). Among patients receiving CSR, those who developed POD were older (78 vs. 74; p = 0.008) and had longer post-operative LOS (14.0 vs. 4.0; p < 0.001). Those having experienced radiotherapy (RT) for cancer within the year before the surgery, were more likely to develop POD (40.0% vs. 6.6% p. < 0.001). Chemotherapy in the year prior to surgery did not increase the risk of POD (6.1% vs. 7.8%; p = 0.721). Among those having non-CRS, a cancer diagnosis did not affect POD. A logistic regression predicting POD indicated that the lower likelihood of POD following CRS was independent of age or gender (OR = 0.40; p < .001); RT within one year prior was independent predictor of higher POD (OR = 5.48; p = 0.003). Our data presentation will include further analysis of POD risk factors. Conclusions: Although older adults receiving CRS were significantly less likely to develop delirium than patients with other high-risk surgeries, it is still important to evaluate POD in this population due to its impact of patients’ outcomes. Further understanding of POD risk factors, such as preoperative RT, would allow the development of targeted interventions that might lessen the risk.