COVID-19 and Delirium

Delirium is characterized by a disturbance in consciousness, as outlined in the DSM-5, which defines it as a disorder affecting attention, awareness, and cognition. Symptoms can overlap with psychosis, including hallucinations and irrational beliefs. Reports indicate that a subset of delirious COVID-19 patients may experience psychotic episodes, where they perceive torturous scenarios or intense physical sensations. Approximately 20-30% of COVID-19 patients experience delirium, with rates climbing to 60-70% in severe cases. This aligns with existing literature indicating that delirium affects a significant portion of patients admitted to intensive care units (ICUs).

Overlooked Cases of COVID-19 Delirium

The initial documentation of delirium linked to COVID-19 emerged from a study in China published on April 10, 2020. Alarmingly, around 75% of delirium cases in critically ill patients go undetected. This oversight stems partly from communication barriers in intubated patients and the multifaceted nature of delirium, which can manifest in various forms: - Hyperactive delirium: Features restlessness, agitation, and hallucinations. - Hypoactive delirium: Exhibits fatigue and slow responses, often misdiagnosed as dementia or depression. - Mixed delirium: Displays symptoms from both hyperactive and hypoactive forms. - Subsyndromal delirium: Represents a mild phase that may progress to full delirium.

Due to delayed recognition, many cases may go undiagnosed for months. This lack of awareness can lead to inadequate monitoring and increased mortality rates, as delirium may signify critical respiratory failure.

Mechanisms Behind COVID-19 Induced Delirium

No singular brain pathology accounts for delirium; rather, it reflects a state where neuronal connections fail to accurately interpret reality. Social isolation, especially during contagious outbreaks, increases vulnerability to delirium by fostering feelings of anxiety and fear. Limited visitation policies in hospitals may exacerbate disorientation among patients.

Additional risk factors include prolonged sedation from mechanical ventilation, which can blur the lines between consciousness and unconsciousness, as well as biological brain damage from various causes. COVID-19 delirium may result from: - Neuroinvasion by the virus: The virus may infiltrate the brain through olfactory pathways or breach the blood-brain barrier, causing neurological issues. - Hypoxia and vascular complications: Lung damage can lead to oxygen deprivation in the brain, resulting in malfunction. - Pre-existing conditions: Factors such as dementia or other health issues can compound the risk of delirium.

Prevention Strategies vs Treatment Options

Enhancing healthcare quality may prevent 30-40% of delirium cases. Current pharmacological interventions have shown limited success, but programs like the Hospital Elder Life Program (HELP) focus on maintaining patient orientation, nutrition, and mobility.

The ABCDEF bundle outlines effective preventive measures for COVID-19: - A: Assess and manage pain. - B: Implement awakening and breathing trials. - C: Choose appropriate analgesia and sedation. - D: Focus on delirium assessment and management. - E: Promote early mobility and exercise. - F: Engage and empower families.

If prevention is not achieved, treatment may include re-orientation, reducing sedative dosages, and enhancing mobility. However, successful outcomes depend on tailoring interventions to individual needs.

Consequences of COVID-19 Delirium

Delirium signifies a critical turning point in illness, being an independent risk factor for prolonged hospitalization and increased mortality. The financial burden of delirium is staggering, with estimates ranging from $38 billion to $152 billion annually in the U.S. alone.

Moreover, recovery does not guarantee a return to pre-illness cognitive function. Studies indicate a doubled risk of cognitive decline in individuals post-delirium, with many experiencing significant impairment months or even years later.

The relationship between coronavirus infections and neuropsychiatric effects has been documented. A meta-analysis highlighted that symptoms suggestive of delirium are prevalent during the acute phases of COVID-19, emphasizing the need for awareness of potential long-term mental health issues.

Moving Forward: Improving Awareness and Care

Preventive measures are crucial, and many risk factors for delirium can be addressed through simple, cost-effective interventions. Despite the evidence, a significant number of delirium cases remain unrecognized in ICUs globally.

Sharon K. Inouye from Harvard Medical School has been instrumental in raising awareness about the implications of COVID-19 delirium. She noted that the pandemic has underscored the importance of recognizing delirium as a serious concern.

Currently, the World Health Organization and other health authorities have not adequately addressed delirium in their COVID-19 guidelines, highlighting a persistent gap in awareness and care for this critical condition.