In geriatric patients, delirium symptoms are related to the anticholinergic burden

Moustafa Naja1, 2*,† Email: [email protected] Jadwiga Zmudka1 Email : [email protected] Sanaa Hannat1 Email : [email protected] Sophie Liabeuf2 Email : [email protected] Jean-Marie Serot1 Email: [email protected] Pierre Jouanny1*,† * Corresponding author Email: [email protected] 1

Department of Geriatric Medicine, Amiens University Medical Center, Amiens, France. 2 Center for Clinical Research, Amiens University Medical Center, Amiens, France. †

Equal contributors

1

Abstract Background Anticholinergic drugs are widely prescribed especially for elderly who are often polymedicated. In these patients the anticholinergic system is weak and an anticholinergic exposure may induce several neuropsychological disorders because acetylcholine is a neurotransmitter implicated in cognitive functions. Delirium corresponds to the presence of an acute cognitive disorder mainly characterized by an altered state of consciousness. A high prevalence of delirium is observed in hospitalized patients. This study evaluates the relationship between the anticholinergic burden (AB) and delirium symptoms.

Methods A prospective, single-center study was carried out on 102 over-75 patients hospitalized in a geriatric medicine department at a university medical center (Amiens, France). The AB was assessed by classifying drug use over a given week into 3 levels (low 1, medium 2 or high 3). An overall, weighted score was established. Delirium symptoms were measured with the Confusion Assessment Method on days 1, 3, 5, 8, 15 and 21. The covariates studied were comorbidities (Charlson score), health status, basic and instrumental activities of daily living, nutritional status (serum albumin), cognition (MMSE score), length of hospital stay and mortality.

Results 102 patients (86.3 ± 5.8 years, 53 women and 49 men) were included. 51.6% of the patients were taking anticholinergic drugs at home (mean AB: 2.13 ± 1.34). The mean ± SD length of stay was 14.5 ± 9.9 days. The prevalence of delirium symptoms was 43.1% at day 1, 36.9% at day 3, 34.8% at day 5, 44.9% at day 8 and 60% at day 21. The AB was correlated with the appearance of delirium symptoms. Delirium symptoms were associated with greater mortality (16.1% and 3.7 % in patients with and without delirium symptoms, respectively; p=0.049), a longer hospital stay (18.09 ± 11.34 vs. 11.75 ± 7.80 days, respectively; p=0.001), greater dependence on discharge (activities of daily living score: 1.57 ± 1.56 vs. 3.41 ± 1.45; p