Polypharmacy and anticholinergic burden as risk factors for postoperative delirium in surgical medicine.

PURPOSE

Polypharmacy is a widespread phenomenon in older patients. In particular, the anticholinergic burden of medication is an important risk factor for delirium due to age-related changes in the cholinergic system.

METHODS

Preoperative medication, including the calculation of the anticholinergic burden (ACB), was recorded in a prospective study (421 patients) to identify potential risks associated with medication intake. Postoperative delirium screening was carried out daily.

RESULTS

The study included 199 women (47.3%) and 222 men (52.7%) aged 80.8 ± 6.7 years and 78.8 ± 6.2 years, respectively. Antidepressants odds ratio (OR) 3.16 (95% confidence interval. CI, 1.51-6.64), antidiabetic drugs OR 2.53 (95% CI 1.27-5.03), neuroleptics OR 3.52 (95% CI 1.70-7.28) and Parkinson medication OR 5.88 (95% CI 1.95-17.7) showed a significantly higher risk for delirium. The ACB score revealed an anticholinergic burden in 43 patients (10.4%). The delirium rate was 25.6% (n = 11) and 11.0% (n = 40) had no anticholinergic burden. A significant correlation can be demonstrated with χ(1) = 7.52, p = 0.006, Cramer's V = 0.136. There was a 2.79-fold higher risk of delirium (OR 2.79, 95% CI 1.31-5.97).

CONCLUSION

The standardized recording of medication is essential, especially when identifying patients at risk of suffering from delirium. The use of the ACB score to assess the anticholinergic burden is a simple and reliable screening tool and should be part of a preoperative geriatric assessment.