From the Guidelines
Delirium can be caused by a multitude of factors, including medications, infections, metabolic disturbances, and environmental factors, with the most recent evidence suggesting that reversible causes account for 30-50% of cases, particularly drugs and poorly controlled pain 1. When considering the potential causes of delirium, it is essential to take into account the complexity of the condition and the various factors that can contribute to its development.
- Medications, such as benzodiazepines, corticosteroids, anticholinergics, opioids, and other drugs with psychoactive properties, can induce delirium 1.
- Infections, including urinary tract infections, pneumonia, or sepsis, can also trigger delirium 1.
- Metabolic disturbances, such as electrolyte imbalances, dehydration, hypo- or hyperglycemia, can contribute to the development of delirium 1.
- Environmental factors, including sleep deprivation, sensory deprivation, or unfamiliar surroundings, can also play a role in the development of delirium 1. The most critical step in managing delirium is identifying and addressing the underlying causes, as treatment of the root cause often leads to resolution of the confused state 1. It is crucial to note that multiple factors often contribute simultaneously to delirium development, and the underlying mechanism involves disruption of neurotransmitter systems, particularly acetylcholine, dopamine, and gamma-aminobutyric acid (GABA) 1. Given the high occurrence rates and significant impact of delirium on patient outcomes, effective strategies for prevention and management should be a priority in healthcare settings 1.
From the Research
Possible Causes of Delirium
Some possible causes of delirium include:
- Infections, such as urinary tract infections (UTIs) and pneumonia 2, 3, 4, 5
- Certain medications 6
- Advanced age 6, 2, 3, 4, 5
- Exposures to other stressors, such as sepsis 3
- Comorbidities, such as dementia 2, 4
- Physiological and metabolic derangement 4
- Asymptomatic bacteriuria (although the evidence is limited) 5
Risk Factors
Risk factors for delirium include:
- Older age 6, 2, 3, 4, 5
- Presence of comorbidities, such as dementia 2, 4
- Infection, such as UTIs and pneumonia 2, 3, 4, 5
- Sepsis 3
- Certain medications 6
- Physiological and metabolic derangement 4
Underlying Mechanisms
The underlying mechanisms of delirium are complex and not well understood, but may involve: