Hospital-induced delirium is a common and distressing condition, particularly affecting older adults during a hospital stay. It is an acute state of confusion that causes significant distress for patients and their families. The prevalence is high, occurring in up to one-third of all hospitalized patients and over 80% of those in the Intensive Care Unit (ICU). Understanding this serious medical state is the first step toward effective prevention and management.
Defining Hospital Delirium
Delirium is characterized as an acute disturbance in attention and awareness that develops rapidly, usually over hours or a few days. The core features involve a reduced ability to direct, focus, sustain, or shift attention, along with a change in cognition, such as memory deficit or disorientation. Unlike chronic conditions like dementia, the onset of delirium is sudden, and its symptoms tend to fluctuate significantly throughout the day.
The condition is officially recognized as a neurocognitive disorder. The syndrome is defined as a direct physiological consequence of an underlying medical condition, substance intoxication, or withdrawal. Delirium is distinct from depression or dementia because of its acute onset and fluctuating course, though it can occur in patients who already have dementia. While it is generally considered a transient cause of mental dysfunction, it should be treated as a medical emergency.
Identifying Risk Factors and Triggers
The development of hospital delirium results from an interaction between factors that make a patient vulnerable and immediate causes within the hospital environment. Pre-existing cognitive impairment, such as dementia, is the strongest vulnerability, increasing the risk by up to 15-fold. Other vulnerabilities include advanced age, severe illness, multiple coexisting medical conditions, and sensory deficits like impaired vision or hearing.
The immediate triggers are often related to the acute medical event or the hospital environment itself. Infections, such as urinary tract or respiratory infections, are among the most common triggers. Other frequent causes include dehydration, electrolyte imbalances, major surgery, and the introduction of new medications, especially those affecting the central nervous system. Environmental factors like sleep deprivation, physical restraints, and catheter use also significantly increase a patient’s risk of developing an episode.
Recognizing the Different Manifestations
Delirium manifests in three distinct subtypes that describe the patient’s level of psychomotor activity. The hyperactive subtype is often the easiest to recognize, characterized by agitation, restlessness, emotional lability, and sometimes hallucinations or delusions. Patients with this presentation may resist care and attempt to remove medical devices.
The hypoactive subtype is characterized by a reduction in psychomotor activity, presenting as lethargy, sluggishness, and quiet withdrawal. Patients may appear drowsy or inactive, which can cause this form to be mistaken for fatigue or depression and is often missed. Hypoactive delirium is the most common type in older adults and is associated with higher rates of poor outcomes. The third presentation is mixed delirium, where the patient fluctuates between periods of hyperactive agitation and hypoactive lethargy, with symptoms changing rapidly throughout the day.
Non-Pharmacological Management and Care
Multicomponent, non-drug interventions are the first line of treatment for hospital delirium, as they address the common risk factors that trigger the condition. These strategies focus on the environment and supportive care and can reduce the incidence of delirium. One central component is maintaining a consistent environment and providing frequent reorientation to time, place, and person, often using clocks, calendars, and familiar objects from home.
Supportive care involves several key actions:
- Optimizing sensory function by ensuring the patient uses their eyeglasses and hearing aids.
- Promoting good sleep hygiene by minimizing noise and light at night and encouraging natural light exposure during the day.
- Encouraging early and progressive mobilization, assisting the patient to walk several times a day when possible.
- Ensuring adequate nutrition and hydration.
- Avoiding the use of physical restraints or unnecessary catheters.
Communication techniques involve using a calm, reassuring tone and avoiding confrontation when a patient expresses fear or distrust. Family presence is highly beneficial, as a familiar person can help the patient feel safer and provide continuous reorientation. These interventions stimulate the patient’s cognitive function, helping to reduce the severity and duration of the confused state.
Medical Interventions and Recovery
Medical management of delirium focuses on identifying and treating the underlying medical condition that triggered the episode. This involves investigation for causes such as infection, metabolic imbalances, or adverse drug effects, which are then treated with specific interventions like antibiotics or fluid replacement. Since delirium is a symptom of acute brain failure, resolving the root physical cause is the most effective way to resolve the confusion.
Pharmacological agents, such as antipsychotics, have a limited and specific role in delirium management. These medications are reserved for cases of severe agitation or psychosis when the patient is a danger to themselves or hospital staff and non-drug methods have failed. Using these drugs requires careful consideration, as many sedating medications can potentially worsen the delirium. The duration of a delirium episode is variable, with most cases resolving within a few days to a week once the underlying cause is addressed.
The condition can persist for several weeks or even months in the most vulnerable patients, particularly those with pre-existing cognitive impairment. Patients who experience delirium face increased risks for complications, including a higher mortality rate and a lower level of functional and cognitive recovery months after the episode. Education for patients and caregivers about the risk of long-term cognitive impact and the necessity of follow-up care is part of the recovery process.