Anticholinergic Burden and Postoperative Delirium in Older Women After Surgery

Objectives: Anticholinergic burden (ACB) is the cumulative impact of taking multiple medications with anticholinergic properties. It is prevalent among elderly adults and is associated with worse clinical outcomes. The primary aim of this study is to identify the association between preoperative ACB and postoperative delirium (POD) in women aged ≥60 years who underwent major pelvic organ prolapse surgery. We hypothesized that ACB is associated with the development of POD.

Methods: This is a secondary analysis of a prospective cohort study in which cognitively intact women aged ≥60 years underwent major prolapse surgery and were assessed for POD during the first postoperative week. POD was diagnosed using the Confusion Assessment Method, which was performed in person on the day of hospital discharge and by phone on postoperative days 1, 3, 5, and 7. We measured anticholinergic burden (ACB) using the validated ACB scale score which is based on patient-reported preoperative medication use. We defined ACB to be an ACB scale score of ≥3. Chi-square (Fisher’s exact) and t-test (Mann-Whitney U) analyses were performed to compare clinical and demographic variables between women with and without ACB. Stepwise multivariable logistic regression (LR) with backward removal for relevant variables with p< 0.2 on univariable LR was performed to examine the association between POD and ACB.

Results: In the original study, there were 20/165 (12.1%) patients who developed postoperative delirium within the first week after prolapse surgery. Mean age was 75.4 years (SD 5.2), and mean BMI was 28.0 kg/m2 (SD 4.4). There were 27 (16.4%) who had ACB. ACB was associated with older age (p=0.007), frailty (p=0.001), worse baseline cognitive function (measured by modified mini-mental status (3MS) exam score) (p=0.006), history of depression (p=0.001), and history of anxiety (p=0.005). On univariate analysis, ACB was significantly associated with POD (odds ratio (OR) 3.37, 95% CI 1.20-9.45). Age and 3MS score were also associated with POD (p < 0.05). On stepwise multivariable LR which included ACB, baseline cognitive function, frailty score, and age, only lower 3MS scores (worse cognitive function) remained significantly associated with POD (aOR 0.83, 95% CI [0.74-0.93]).

Conclusions: ACB is independently associated with POD. However, when considering other age-related factors, only decreased baseline cognitive function (without a diagnosis of cognitive disorder) remained significantly associated with POD. Given that ACB is potentially modifiable, both factors should be considered preoperatively to assist with surgical counseling and recommendations for optimal postoperative recovery.