Acute brain dysfunction—encompassing delirium, coma, and agitation—is one of the most common and consequential complications of critical illness, yet it remains under-recognized and inconsistently managed. In this session, Drs. Vasilevskis and Kaiksow outlined a pragmatic, evidence-based roadmap for hospitalists to better identify, prevent, and manage these conditions across care settings.
A key conceptual shift emphasized early is that critical illness is not confined to the intensive care unit (ICU). Rather, it is a condition that can occur across emergency departments, general wards, and ICUs alike. Similarly, acute brain dysfunction exists along a spectrum—from hypoactive delirium and coma to hyperactive delirium and agitation—rather than as discrete diagnoses. This framework is particularly relevant for hospitalists, who frequently encounter these syndromes outside traditional ICU environments.
The epidemiology underscores the scope of the problem. Delirium affects approximately one-third of hospitalized patients over age 70, with half present on admission and half developing during hospitalization. Rates are even higher in surgical and mechanically ventilated populations, exceeding 75% in the latter. Delirium arises from the interaction of predisposing vulnerabilities—such as age, dementia, and sensory impairment—and precipitating insults, including medications, infections, and surgery. This dual-hit model highlights opportunities for prevention through mitigation of modifiable risk factors.
The consequences of acute brain dysfunction are profound and extend well beyond hospitalization. Patients who experience delirium have significantly increased mortality and are at risk of long-term cognitive impairment resembling moderate traumatic brain injury or early Alzheimer’s disease. Notably, hospitalization alone is not associated with cognitive decline; delirium appears to be the key driver. Functional outcomes are similarly affected, with higher rates of institutionalization among patients who develop delirium.
The burden extends beyond patients. Caregivers report substantial emotional and situational stress, often describing the experience as frightening and isolating. For healthcare workers, acute brain dysfunction contributes to workplace violence, burnout, and injury. At the system level, delirium is associated with longer lengths of stay and increased costs, reinforcing its importance as both a clinical and operational priority.
Despite its prevalence and impact, delirium remains under-recognized. Physicians identify delirium in only about 28% of cases, and nurses in approximately 35%. To address this gap, the presenters emphasized the routine use of validated bedside tools. The Richmond Agitation-Sedation Scale (RASS) provides a standardized measure of arousal and serves as a foundation for assessment. Importantly, even subtle deviations are clinically meaningful: a RASS score other than 0 (i.e., not “alert and calm”) should be considered abnormal. This represents an optimal screening threshold, as any deviation is both sensitive and specific for delirium and signals an altered level of consciousness requiring further evaluation.
The Brief Confusion Assessment Method (bCAM) builds on this by offering a structured approach to diagnosing delirium, incorporating mental status changes, inattention, level of consciousness, and disorganized thinking. Pain, a critical and often overlooked contributor, should be assessed using validated tools such as the Critical-Care Pain Observation Tool (CPOT). Together, these instruments enable clinicians to operationalize the detection and monitoring of acute brain dysfunction.
The principle that “you can’t change what you don’t measure” underpins prevention efforts. Evidence-based strategies focus on modifiable risks, particularly medication exposure and immobility. Polypharmacy—especially involving benzodiazepines, anticholinergics, and sedative-hypnotics—increases delirium risk, making medication review and deprescribing essential. Emerging evidence suggests a potential role for melatonin, though routine use remains under investigation.
Mobility represents another critical target. Traditional practices of immobilization are increasingly recognized as harmful, contributing to delirium, weakness, and long-term disability. Early mobilization, including physical and occupational therapy in mechanically ventilated patients, improves functional outcomes and reduces delirium duration. Implementation, however, requires a cultural shift toward proactive mobility.
These strategies are most effective when integrated into a comprehensive framework such as the ABCDEF bundle: assessing pain management; both spontaneous awakening and breathing trials; careful sedation selection; delirium monitoring; early mobility; and family engagement. Large-scale implementation studies demonstrate that higher adherence is associated with reductions in delirium, coma, mechanical ventilation, and restraint use. Importantly, the bundle translates guideline recommendations into practical bedside actions.
The presenters also highlighted the cyclical nature of acute brain dysfunction. Sedation, mechanical ventilation, weakness, and delirium reinforce one another, leading to cognitive impairment, functional decline, institutionalization, and mortality. Breaking this cycle requires coordinated, multidisciplinary efforts focused on minimizing iatrogenic harm.
Management of established delirium remains challenging, with limited pharmacologic options. Nonpharmacologic strategies—including treating underlying causes, optimizing pain control, and tailoring the environment—remain first-line. The “TADA” approach—tolerate, anticipate, and don’t agitate—provides a practical framework, emphasizing minimization of unnecessary devices, anticipation of patient behaviors, and avoidance of triggers such as repeated reorientation attempts that may worsen distress. Verbal de-escalation and supportive care are essential.
When pharmacologic therapy is necessary for patient or staff safety, clinicians should use the lowest effective dose and prioritize oral over parenteral routes; combination regimens—particularly benzodiazepines with antipsychotics—should be avoided, when possible, while dexmedetomidine may represent a less harmful alternative in select patients.
Looking ahead, future directions include innovations in mobility, behavioral interventions, and environmental design. However, the presenters emphasized that the most impactful tools are already available and underutilized. For hospitalists, the priority is consistent application of existing evidence-based practices.
In summary, acute brain dysfunction is a common, costly, and potentially preventable complication of hospitalization. Through systematic assessment, targeted prevention, and multidisciplinary care models such as the ABCDEF bundle, hospitalists can meaningfully improve outcomes for patients, caregivers, and healthcare systems alike.
Dr. Dockstader
Dr. Dockstader is an assistant professor of internal medicine and a hospitalist at the University of New Mexico in Albuquerque, N.M., where she is also the director of clinical documentation and observation service line director in the department of medicine.