Drug-induced confusional states: the usual suspects?

Incidence and risk factors for acute delirium in older patients with a hip fracture: A retrospective cohort study

This retrospective cohort study aimed to determine the incidence, and preoperative, intraoperative, and postoperative risk factors for postoperative delirium in older patients undergoing surgical fixation of a hip fracture. Electronic medical records were examined of 260 patients who underwent a surgical fixation of a hip fracture between June 2017 and October 2018 at a university-affiliated tertiary care hospital in Victoria, Australia. Demographic, clinical, and perioperative data were examined for potential risk factors for postoperative delirium. Of the 260 patients, 63 patients (24.2%) developed delirium postoperatively. Univariate logistic regression analysis indicated that advanced age, comorbidity, cognitive impairment, dementia, American Society of Anesthesiologists score, and antipsychotic usage were significant risk factors for delirium, while doses of paracetamol, fentanyl, and diazepam showed complex associations. Multivariate logistic regression analysis determined comorbidity and cognitive impairment as independent risk factors for the development of delirium. This study demonstrates the importance of evaluation of medications prescribed in the perioperative period as modifiable risk factors, in order to identify patients at high risk of delirium and enable targeted monitoring and treatment during patients' hospitalization.

Multiple anticholinergic medication use and risk of hospital admission for confusion or dementia

OBJECTIVES

To identify the association between use of multiple anticholinergic medications and risk of hospitalization for confusion or dementia.

DESIGN

Retrospective cohort study conducted over 2 years between July 2010 and June 2012, using administrative claims data from the Australian Department of Veterans' Affairs.

SETTING

Australia.

PARTICIPANTS

Australian veterans dispensed at least one moderately or highly anticholinergic medication in the year before study start.

MEASUREMENTS

Cumulative anticholinergic use on each day of the study period was determined. The association between hospitalization for confusion or dementia and number of anticholinergic medications used at the time of admission was compared against times during which participants were not taking anticholinergic medications. Sensitivity analyses were undertaken limiting the outcome to admissions for acute confusion and excluding individuals taking antipsychotics.

RESULTS

Adjusted results showed a significantly greater risk of hospitalization for confusion or dementia when individuals were taking two or more anticholinergic medications. The adjusted incident rate ratios (IRRs) were 2.58 (95% confidence interval (CI) = 1.91-3.48) for those taking two anticholinergics and 3.87 (95% CI = 1.83-8.21) for those taking three or more. Sensitivity analyses in which participants taking antipsychotic medications were excluded and the outcome was limited to acute confusion also found similar risks for those taking two (IRR 1.82, 95% CI = 1.18-2.80) and three or more (IRR = 3.98 95% CI = 1.50-10.58) anticholinergic medications.

CONCLUSION

Taking more anticholinergic medications is associated with greater risk of hospitalization for confusion or dementia. Strategies to reduce anticholinergic medication burden are likely to translate into significant health benefits.