Postoperative delirium

What is postoperative delirium?

Postoperative delirium is an acute, mostly temporary state of confusion and is also referred to as transitory syndrome or acute organic psychosyndrome. It occurs in 5-15% of all patients. At the same time, various brain functions are restricted. There are changes in consciousness, thinking, moving, sleeping and feeling. It mainly affects elderly patients, can be very different and changes over time.
From very restless and sometimes aggressive to very quiet and barely responsive patients, there are all variants of delirium.

The reasons

Postoperative delirium can usually not be traced back to a specific cause. It is usually a combination of different factors. Medication is often put on or off during a hospital stay and surgery planning. These changes can trigger postoperative delirium over time.

Insufficient oxygen supply to the brain in ventilated patients, organ failure (lungs, heart, liver, kidneys), and underlying diseases such as severe infections are further causes.Changes in the electrolyte and acid-base balance must be strictly monitored during an operation and corrected as quickly as possible. Elderly patients with existing mental illnesses e.g. Dementia is often difficult to adapt to new situations. Changing the environment can make the state of confusion worse.

Find out all about the topic here: Passage syndrome (delirium).

The heart surgery

Cardiac surgery patients particularly often show postoperative delirium. In some studies, up to 46% of patients are spoken of. Particularly during interventions with a heart-lung machine, there are significant changes in the circulatory system that must be compensated for by the anesthetist. Cardiac surgery patients often have low cardiac output, resulting in a lack of oxygen in the brain and low blood pressure. Both risk factors for delirium.
In addition, you have a higher serum cortisol due to stress reactions and increased inflammation parameters due to the large and long surgical procedure. Due to the complex operations, there are more postoperative complications.

The stay in the intensive care unit

Intensive care patients have had serious, often life-threatening, underlying diseases and often major operations. The organ functions are often limited and are partly taken over by machines. This demands a lot of energy from the body, the oxygen consumption is increased and the risk of an insufficient supply and the development of toxic substances in the body is significantly increased.

Pain therapy is a very important factor, especially in sedated patients it is often difficult to recognize pain. A lack of pain therapy is also a cause of delirium. A lack of sunlight (no window seat in the intensive care room) and disturbing noises from machines, fellow patients or staff means that falling asleep and staying asleep or the entire day-night rhythm is disturbed, which promotes the development of delirium.

Anesthesia in the elderly

The majority of patients who develop postoperative delirium are> 60 years of age. The reason for this is the presence of several risk factors that favor delirium. In addition to age, impaired vision and hearing, underlying diseases such as diabetes, high blood pressure, stroke, atrial fibrillation or mental impairments such as Dementia too.

Older patients also often take several drugs (polypharmacy). During / after the anesthesia, drugs are also administered that can have a dilirant effect, such as Opiates and benzodiazepines. Elderly patients are prone to low blood pressure, blood sugar and low sodium during general anesthesia. It is therefore particularly important for old people to keep the duration of anesthesia as short as possible or, if possible, to switch to regional anesthesia.

Find out more about the topic here: Anesthesia in the elderly.

The symptoms

Postoperative delirium usually develops within the first four days after surgery / general anesthesia. Affected patients mostly suffer from disorientation, especially a temporal and situational confusion. The orientation to the place and to the person are rather intact.
Further symptoms are fear and restlessness, in this context patients often react irritably or even aggressively towards nursing staff or relatives. An increased urge to move often leads to falls with lacerations, broken bones or the dislocation of recently operated joints.

In other cases, those affected tend to withdraw, hardly speak and refuse to eat. The consequences are weight loss and exicosis (lack of fluid), which can have life-threatening consequences. A large proportion of those affected report hallucinations. Thinking is often significantly slowed down and disordered. Patients talk in a rambling, erratic manner and often do not answer a specific question but rather ignore the topic. The symptoms appear mainly in the evening and at night and fluctuate during the day, which results in a disturbed sleep-wake cycle. This in turn exacerbates the symptoms.

Since the symptoms of postoperative delirium are very variable and can vary greatly in their intensity during the course, the diagnosis is often made late. In order to avoid complications such as infections (especially urinary tract infections and pneumonia) or wound healing disorders, a quick diagnosis and rapid initiation of therapy are important!

Those are the risk factors

The greatest risk is the age of the patient. Most patients with postoperative delirium are> 60 years and already suffer from psychological abnormalities before the procedure, such as dementia or suffer from other underlying diseases such as diabetes, high blood pressure or atrial fibrillation that predispose to delirium. There are also differences in the individual disciplines. Delirium is more common in cardiac surgery and intensive care patients.

Another risk factor is taking various drugs, so-called dilirogenic drugs such as Amitriptyline, atropine, amantadine, baclofen, olanzapine, tricyclic antidepressants. A disturbed oxygen supply to the brain, lack of fluids and electrolyte disorders, as well as malnutrition also favor the development of delirium.

Also read the article: Aftermath of anesthesia.

The diagnosis

A quick and reliable diagnosis of postoperative delirium and immediate therapy are crucial for the further course of the disease. However, due to the variable symptoms, this is not always easy. Therefore an algorithm was developed to make a diagnosis faster. The algorithm (Confusion Assessment Method) comprises four criteria: unstructured thinking, lack of attention, changes in consciousness and fluctuations (fluctuations).
The degree of sedation is also recorded: very argumentative, agitated (pulls drainage, catheter), restless, attentive, sleepy, slightly sedated reacts to speech, deeply sedated reacts to touch, cannot be awakened.

In addition, it must always be taken into account whether the mental state was already restricted before the operation and to what extent it has changed after the anesthesia. The diagnosis of hypoactive delirium in which the patient withdraws and sleeps a lot is particularly difficult. These patients quickly drown in the hectic everyday clinical routine.

The treatment

The therapy consists of various measures. Basic measures to maintain orientation (glasses, hearing aid) should be carried out for all elderly or general patients in intensive care units. Regular and extensive mobilization, avoidance of dehydration, as well as a balanced diet and maintaining the sleep-wake rhythm can prevent the development of delirium or significantly improve it. Individually tailored pain therapy and oxygenation can also improve the state of confusion
Timely therapy for the underlying disease, e.g. The administration of antibiotics in sepsis has a positive effect on the psychological state.

Drug therapy for postoperative delirium is often difficult. If a certain drug can be identified as the triggering factor, this drug must be discontinued immediately and switched to another substance. The administration of neuroleptics for prophylaxis in older patients is discussed in various studies before cardiac surgery. Here e.g. Olanzapine is quite effective, but is not officially approved for it (off-label use). Antipsychotics such as haloperidol in combination with quetiapine, risperidone or olanzapine are also not officially approved but are still used in some cases, but only under strict ECG control.

More information about Neuroleptics you'll find here.

The relatives can do that

Relatives are often the first to recognize when "something is wrong" with a known person. Postoperative delirium can develop slowly or as an atypical variant, so that doctors and nurses can only make the diagnosis later. As a relative, speak to the responsible medical staff if you are suspicious and describe the observed changes. If the diagnosis has already been made, it is important to be there for the person concerned. Bringing current photos or playing favorite music can help to regain orientation. If the relative does not react differently than expected or insists on an idea, be lenient, do not discuss. You'd better try again at a later point in time or redirect the conversation to another topic.

In the case of aggressive behavior, self-protection is especially important; never try to hold onto your loved one, you can hurt him or yourself very much. Try to stay calm and do not take anything personally, the delirium usually subsides after a few days.