Anesthesia delirium, also known as postoperative delirium (POD), is a temporary state of confusion and disorientation that can occur after surgery with anesthesia. While often reversible, it is a common occurrence, particularly among older adults undergoing surgical procedures.
Signs and Symptoms of Postoperative Delirium
Patients experiencing postoperative delirium often exhibit fluctuating symptoms. Disorientation is common, where individuals may not know their location, the current time, or recognize family members. They might also struggle with memory, finding it difficult to recall recent events or conversations.
Agitation and restlessness are frequently observed, sometimes manifesting as attempts to climb out of bed or uncooperative behavior. Conversely, some patients may become unusually sleepy or lethargic, a form known as hypoactive delirium, which can be harder to detect. Hallucinations, disorganized thinking, slurred speech, rapid mood swings, or difficulty focusing attention may also occur.
Contributing Risk Factors
Several factors can increase an individual’s likelihood of developing postoperative delirium, often acting in combination. Patient-related factors influence this risk. Advanced age is a factor, with individuals over 65 years having a higher risk that increases with age.
Pre-existing cognitive impairment, such as dementia, or a history of prior delirium episodes also elevate the risk. Other medical conditions, including infections, dehydration, poor nutrition, depression, and multiple existing health problems (comorbidities), can contribute. Medications, particularly those with anticholinergic properties, benzodiazepines, and opioids, can also increase the risk.
Surgery-related elements also play a role. Major procedures, such as cardiac or orthopedic surgeries, carry a higher risk compared to less invasive operations like cataract surgery. The type and duration of anesthesia administered, with deeper or longer anesthesia sometimes increasing risk, and uncontrolled postoperative pain are additional factors.
Distinguishing Between Postoperative Conditions
It is important to differentiate postoperative delirium from other conditions that can affect cognition after surgery due to differences in timing and presentation. Emergence delirium occurs immediately as a patient wakes up from anesthesia, typically in the recovery room. This state is short-lived, lasting from a few minutes to about an hour, and is more commonly observed in children, who might exhibit agitation, disorientation, or combativeness.
Postoperative delirium usually manifests later, typically hours to days after surgery. Its symptoms can persist for days or weeks, characterized by a fluctuating course of confusion, altered mental status, and a disturbance in attention, awareness, and thinking that is a change from the patient’s baseline.
Postoperative cognitive dysfunction (POCD) is a more subtle and often longer-term condition involving persistent issues with memory and concentration. Unlike delirium, which is an acute confusional state, POCD can last for weeks or months following surgery and may not be immediately obvious. While postoperative delirium and POCD can share some risk factors and may co-occur, they are considered distinct manifestations of cognitive changes after surgery.
Management and Resolution
Addressing postoperative delirium primarily involves non-pharmacological interventions. Creating a calm, consistent environment is beneficial, including frequent reorientation to time, place, and situation. Ensuring the patient has their glasses and hearing aids, if needed, can help them better interact with their surroundings.
Effective pain management is also important, as uncontrolled pain can worsen confusion. Promoting normal sleep-wake cycles by reducing nighttime disturbances and encouraging daytime activity can aid in recovery. Encouraging family presence and engagement can provide comfort and continuity. While medications like antipsychotics may be used for severe agitation that poses a risk, they are not a first-line treatment. For most patients, postoperative delirium resolves as they recover from surgery and underlying contributing factors are addressed.