Side effects of general anesthesia in elderly people
Older people are generally exposed to the same risks under general anesthesia as younger people. Injuries may occur when inserting the breathing tube (intubation), followed by sore throats due to slight injuries to the mucous membranes. Injury to the teeth during intubation is also possible.
Furthermore, allergic reactions to the anesthetics or painkillers used may occur. Bruising or inflammation may remain in the area of the insertion point of venous and/or arterial accesses.Apart from these general anesthesia risks, there is evidence that older people are more affected by general anesthesia than young patients. Often the already aged organism needs longer to fully recover from general anaesthesia.
In addition, patients over 60 years of age are more likely to develop a so-called “through syndrome” or postoperative delirium after surgery. This is characterized by longer lasting states of confusion after waking up from general anesthesia. Most patients are therefore rather apathetic and introverted postoperatively (hypoactive delirium), other patients suffer from hallucinations and severe states of agitation (hyperactive delirium).
Other suspected side effects of general anesthesia in older age are a longer lasting impairment of thinking and an increased risk of dementia. However, the latter is controversial and not clearly attributable to general anesthesia. It could also be the operation itself, which, due to the physical strain involved, allows a previously unknown dementia to progress more quickly.
It is noticeable, however, that elderly people often need several months following general anesthesia to regain complete control of their everyday life without any restrictions. The exact circumstances of cognitive impairment in elderly people following general anesthesia have not yet been conclusively clarified, as ongoing studies are producing partly contradictory results. Some affected persons, especially elderly patients, develop a continuity syndrome after general anesthesia.
This is similar to dementia in terms of the behavior of those affected, but usually recedes after a few days. However, a slight confusion in the first few hours after anaesthesia is observed in almost all patients and usually subsides within a few hours. This is an after-effect of the anaesthetic drugs which have not yet been completely broken down and is therefore a natural reaction of the body.
Some of the substances used for anaesthesia cause confusion in patients. These substances include benzodiazepines such as midazolam, which are administered for sedation before surgery. After major surgery, confusion, disorientation and even aggressive behavior can occur.
A now somewhat outdated term for this condition is the so-called “continuity syndrome”, as the changes usually regress completely (are continuous). A therapy is not known here. However, patients should be monitored by means of ECG and blood pressure control.
The state of confusion can last for hours, days and in rare cases even longer. Other physical causes of confusion after surgery under anesthesia can be low blood sugar or lack of oxygen. Complications during the surgical procedure, such as encephalopathy (a disease of the brain), also lead to confusion and should be treated by a physician.
Due to the profound influence on processes in the brain and consciousness, such as the elimination of motor and sensory perception, this side effect can be easily understood. The technical term for confusion after general anesthesia is “postoperative delirium“. With 5-15% of patients affected, which can increase up to 50% during difficult and long lasting operations, confusion is one of the most common side effects of general anesthesia.
There are great differences in the extent, duration and timing of its occurrence. In general, confusion can occur in all patients, although older people suffer most. Usually the confusion starts immediately after waking up or a few hours after waking up and does not last long.
During this time the patients are severely restricted in their thinking and attention. Both temporal and spatial orientation is difficult in many cases. In addition, disturbances of the sleep-wake rhythm can occur as further side effects and problems such as loss of appetite and lack of affect can be observed.
The majority of patients suffer from the hypoactive form of delirium, which means that they lie quietly in bed and have slowed reflexes and reactions. There is a tendency to sleep. In about 15% of the patients a hyperactive form with agitation and delusions occurs.
