Regarding: Delirium and frailty in older adults: Clinical overlap and biological underpinnings

Dear Editor,

The review by Bellelli et al. recently published in the Journal of Internal Medicine examines the relationship between frailty and delirium—two geriatric syndromes that significantly impact morbidity, mortality, functionality, cognition, quality of life, healthcare costs, and caregiver burden [1]. The authors assess the current evidence regarding how these conditions share risk factors, prevalence, consequences, and pathophysiology and whether they potentially constitute a syndrome in their own right. Although their findings are of significant importance and raise other compelling discussions, we would like to offer some additional comments for consideration.

First, their findings highlight our limitations in understanding the pathophysiology of these conditions. It is noteworthy that various medications targeting different mechanisms thought to be involved in the occurrence of delirium are being investigated for prevention and treatment. However, the results remain inconsistent and do not significantly influence severity, duration, or recurrence [2].

It is also pertinent to question how frequently we underdiagnose cognitive decline upon hospital admission. We know that this decline often goes unnoticed by family members and caregivers, making it less likely to be spontaneously reported in clinical settings. Such an assessment is crucial for investigating a possible connection between frailty and delirium, given that cognitive decline is a common risk factor for both conditions, though it may be less evident for the untrained eye in the earlier stages.

Moreover, we face a clinical reality—previously highlighted by large studies—regarding the inconsistency of clinical practices in delirium prevention. We must ask whether—were these protocols to be effectively implemented—we could prevent delirium even in frail patients. This would contribute to either reinforcing or undermining the hypothesis of a singular syndrome. Nevertheless, we still lack high-quality clinical evidence regarding the best strategies for preventing delirium, let alone their consistent implementation in clinical practice [3].

It seems imperative to engage in a multidisciplinary approach to the prevention of these conditions. While this may entail short-term increases in healthcare expenditures for ongoing education of clinical teams, hiring additional staff, and logistical reorganization, studies on delirium suggest that its prevention may result in reduced rates of hospital length of stay and readmission [4]. Moreover, frail patients who develop delirium are more susceptible to a feedback loop of these conditions, which can lead to adverse clinical outcomes, including increased rates of infection, hospitalization, and intensive care unit admissions, as well as the utilization of sedatives.

It is important to note that although the review by Bellelli et al. contributes to the compilation of studies on the relationship between frailty and delirium, it does not constitute a systematic review conducted with full adherence to established guidelines and the inclusion of multiple databases. Nevertheless, their findings highlight challenges in managing these conditions and future research directions to explore the extent of their interrelationship.

José Lucas Sena da Silva: Conceptualization; writing—original draft; writing—review and editing. Juliana Caldas: Writing—review and editing; supervision.

The authors declare no conflicts of interest.