Memory disorders
In the context of anesthesia, drugs are often administered specifically to cause retrograde amnesia. This means that patients should lose their memories after an often unpleasant and painful procedure. Drugs that cause this memory altering effect are for example benzodiazepines, which are administered before the operation to calm the patient.
Anaesthetics such as propofol or etomidate cause loss of consciousness and anterograde amnesia, so that the patient cannot remember the time during the surgery. These drugs act on so-called GABA receptors in the brain and lead to the amnesia. However, these receptors also have the property of blocking the transition of information from short to long-term memory, which is reinforced by the anesthetic drugs.
This effect is also desired to a small extent and ensures that the patient does not remember the previous operation (retrograde amnesia). This influence on the memory only takes place during the period of effect of the respective medication (possibly even a few hours after the operation). Long-lasting, permanent disturbances and changes in memory are not usually to be expected under anaesthesia.
A restriction of memory beyond the end of the operation is undesirable. Although this is usually only temporary, it can last for months or in rare cases be permanent. Older patients over 60 years of age are particularly affected.
To prevent this complication, patients over 60 are monitored more intensively. In addition, attempts are made to use regional anesthesia procedures more frequently, which have a lower risk of such complications. In case of permanent memory loss after surgery under anesthesia, physical causes or complications during surgery should be excluded.
These types of side effects after general anesthesia are usually self-limiting, so that the confusion disappears after hours or at most a few days. However, it is not uncommon to describe that even after discharge of the patient, there may still be isolated deficits in memory and thinking ability. For example, the car is no longer found in the parking lot.
As a significantly more negative type of side effects, in some cases a so-called cognitive dysfunction can occur after general anesthesia. This is a confusion that only occurs days or weeks after surgery and usually has a worse prognosis than postoperative delirium. Concentration is restricted, the ability to think is reduced.
In older people, this form of confusion sometimes turns into dementia that cannot be reversed. What exactly causes all these side effects after general anesthesia is not well understood. All in all, confusion is one of the more common side effects that are taken into account. Only if the symptoms persist should a clinic be visited again.
