Delirium is an acute and fluctuating disturbance in a person’s mental state, often observed in hospitalized patients. This condition involves changes in attention and awareness, representing a departure from an individual’s usual baseline brain function. It can manifest rapidly, typically over hours to a few days, and its severity can vary throughout the day. Recognizing delirium is important for patient recovery.
What is Postoperative Delirium
Postoperative delirium (POD) is a specific type of delirium that occurs after a surgical procedure and anesthesia. It presents as a sudden, fluctuating disturbance in a person’s attention and cognitive abilities, distinguishing it from typical post-anesthesia grogginess or chronic conditions like dementia. POD can appear anywhere from minutes after anesthesia to up to seven days following surgery, or even until hospital discharge. It is a temporary condition, though its presence can significantly affect a patient’s recovery trajectory.
POD is characterized by impaired consciousness, a reduced ability to focus, maintain, or shift attention, and changes in cognitive function like memory problems or disorientation. Unlike dementia, which involves a gradual and permanent decline in brain function, delirium is an acute and usually reversible neurocognitive syndrome. Hypoactive delirium, where the patient appears sleepy and inactive, is the most common form of POD, although hyperactive and mixed forms also exist.
How to Recognize the Signs
The signs of postoperative delirium can vary among individuals and fluctuate throughout the day, sometimes worsening in the evening or at night. A person experiencing POD may show increased sleepiness or hyperactivity, along with difficulty waking up from anesthesia. Confusion and disorientation are common, where individuals may not know their name, where they are, or why they are in the hospital.
Signs can include:
Difficulty remembering, disorganized thinking, or speech problems.
Agitation, restlessness, irritability, or becoming lethargic and less alert.
Unusual or rapidly changing emotions, including tearfulness, anxiety, anger, or aggression.
Perceptual disturbances, like hallucinations (seeing or hearing things that are not there) or delusions (paranoid thoughts), which can be frightening.
Why it Happens
Postoperative delirium arises from a combination of predisposing and precipitating factors.
Predisposing Factors
These factors are intrinsic to the patient and present before surgery, increasing their vulnerability. They include:
Advanced age, particularly over 65, is a risk factor, with higher incidence rates in older adults.
Pre-existing cognitive impairment, such as dementia, or a history of previous delirium episodes.
Multiple medical conditions like heart or kidney failure, depression, or a history of stroke.
Poor physical health, hearing or vision difficulties.
Substance abuse, including alcohol, and the use of certain psychotropic medications.
Precipitating Factors
These are immediate triggers related to the surgical or medical experience. They include:
The type, duration, and invasiveness of the surgery itself, with major procedures like hip, heart, or open-chest surgeries carrying a higher risk.
Anesthesia, particularly its depth.
Postoperative complications such as infection, dehydration, electrolyte imbalances, and unrelieved pain.
An intensive care unit stay, prolonged intubation, sleep deprivation, and the use of physical restraints.
Care and Prevention
Preventing postoperative delirium often involves a comprehensive approach, with up to 40% of cases in hospitalized older adults considered preventable.
Before Surgery
Before surgery, healthcare providers may conduct pre-surgery cognitive tests to establish a baseline for mental function. Optimizing a patient’s health, including addressing malnutrition or dehydration, and reviewing medications that could induce delirium, are important preparatory steps. Avoiding certain drugs after surgery, such as those for anxiety or insomnia that can affect the nervous system, is also recommended.
During Hospital Stay
Non-pharmacological strategies are emphasized for both prevention and management:
Encouraging early and frequent mobilization, such as walking multiple times daily.
Maintaining a consistent sleep-wake cycle by opening window shades during the day and dimming lights at night.
Using reorientation strategies, where staff calmly remind the patient of their location and the time.
Ensuring adequate hydration and nutrition, along with managing pain using non-opioid medications when possible.
Encouraging family involvement through regular visits, conversation, and bringing familiar objects from home.
In cases of severe agitation, medications may be considered, but physical restraints are generally avoided as they can worsen confusion.