Early detection of delirium in older medical inpatients: prodrome, predictors and motor subtyping

Background Delirium is highly prevalent, especially in older patients. It independently leads to adverse outcomes, but remains under-detected, particularly hypoactive forms. Although early identification and intervention is important, delirium prevention is key to improving outcomes. The delirium prodrome concept has been mooted for decades, but remains poorly characterised. Greater understanding of this prodrome would promote prompt identification of delirium-prone patients, and facilitate improved strategies for delirium prevention and management. Methods Medical inpatients of ≥70 years were screened for prevalent delirium using the Revised Delirium Rating Scale (DRS--‐R98). Those without prevalent delirium were assessed daily for delirium development, prodromal features and motor subtype. Survival analysis models identified which prodromal features predicted the emergence of incident delirium in the cohort in the first week of admission. The Delirium Motor Subtype Scale-4 was used to ascertain motor subtype. Results Of 555 patients approached, 191 patients were included in the prospective study. The median age was 80 (IQR 10) and 101 (52.9%) were male. Sixty-one patients developed incident delirium within a week of admission. Several prodromal features predicted delirium emergence in the cohort. Firstly, using a novel Prodromal Checklist based on the existing literature, and controlling for confounders, seven predictive behavioural features were identified in the prodromal period (for example, increasing confusion; and being easily distractible). Additionally, using serial cognitive tests and the DRS-R98 daily, multiple cognitive and other core delirium features were detected in the prodrome (for example inattention; and sleep-wake cycle disturbance). Examining longitudinal motor subtypes in delirium cases, subtypes were found to be predominantly stable over time, the most prevalent being hypoactive subtype (62.3%). Discussion This thesis explored multiple aspects of delirium in older medical inpatients, with particular focus on the characterisation of the delirium prodrome. These findings should help to inform future delirium educational programmes, and detection and prevention strategies.

Patterns of psychotropic prescribing and polypharmacy in older hospitalized patients in Ireland: the influence of dementia on prescribing

Neuropsychiatric Symptoms (NPS) are ubiquitous in dementia and are often treated pharmacologically. The objectives of this study were to describe the use of psychotropic, anti-cholinergic, and deliriogenic medications and to identify the prevalence of polypharmacy and psychotropic polypharmacy, among older hospitalized patients in Ireland, with and without dementia. All older patients (≥ 70 years old) that had elective or emergency admissions to six Irish study hospitals were eligible for inclusion in a longitudinal observational study. Of 676 eligible patients, 598 patients were recruited and diagnosed as having dementia, or not, by medical experts. These 598 patients were assessed for delirium, medication use, co-morbidity, functional ability, and nutritional status. We conducted a retrospective cross-sectional analysis of medication data on admission for 583/598 patients with complete medication data, and controlled for age, sex, and co-morbidity. Of 149 patients diagnosed with dementia, only 53 had a previous diagnosis. At hospital admission, 458/583 patients experienced polypharmacy (≥ 5 medications). People with dementia (PwD) were significantly more likely to be prescribed at least one psychotropic medication than patients without dementia (99/147 vs. 182/436; p < 0.001). PwD were also more likely to experience psychotropic polypharmacy (≥ two psychotropics) than those without dementia (54/147 vs. 61/436; p < 0.001). There were no significant differences in the prescribing patterns of anti-cholinergics (23/147 vs. 42/436; p = 0.18) or deliriogenics (79/147 vs. 235/436; p = 0.62). Polypharmacy and psychotropic drug use is highly prevalent in older Irish hospitalized patients, especially in PwD. Hospital admission presents an ideal time for medication reviews in PwD.