The postoperative delirium usually develops within the first four days after an operation/general anaesthetic. Affected patients usually suffer from disorientation, especially a temporal and situational confusion. The orientation to the place and the person is rather intact.
Further symptoms are anxiety and restlessness, patients often react irritably or even aggressively towards nursing staff or relatives in this context. An increased urge to move often leads to falls with lacerations, broken bones or the dislocation of freshly operated joints. In other cases, affected persons 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 clearly slowed down and disordered.
Patients talk verbosely, erratically and often do not answer a specific question but talk off topic. The symptoms appear mainly in the evening and at night and fluctuate in the course of the day, resulting in a disturbed sleep-wake rhythm. This in turn intensifies the symptoms. Since the symptoms of postoperative delirium are very variable and can vary greatly in intensity over the course of the day, 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 therapy initiation is important!
These are the risk factors
The greatest risk is the age of the patient. Most patients with postoperative delirium are >60 years of age and already suffer from mental abnormalities before the procedure, such as dementia, or suffer from other underlying diseases such as diabetes, high blood pressure or atrial fibrillation, which predispose them to delirium. Differences are also apparent in the individual disciplines.
Deliriums are more common in patients undergoing heart surgery and intensive care. A further risk factor is the use of various drugs, so-called dilirogenic drugs such as amitryptilin, atropine, amantadine, baclofen, olanzapine, tricyclic antidepressants. A disturbed oxygen supply to the brain, lack of fluids and electrolyte disorders, as well as malnutrition also favour the development of delirium. .
A quick and reliable diagnosis of the postoperative delirium and an immediate therapy is crucial for the further course of the disease. Due to the variable symptoms, however, this is not always easy. Therefore, an algorithm was developed to make a diagnosis more quickly.
The algorithm (Confusion Assessment Method) comprises four criteria: unstructured thinking, lack of attention, changes in consciousness and fluctuations. Furthermore, the degree of sedation is recorded: very belligerent, agitated (pulling drains, catheters), restless, attentive, sleepy, lightly sedated reacts to speech, deeply sedated reacts to touch, unawakened. In addition, it must always be taken into account whether the mental state was already limited before the operation and to what extent it changed after the anaesthetic. It is particularly difficult to diagnose a hypoactive delirium where the patient withdraws and sleeps a lot. In the hectic clinical routine, these patients quickly drown.