Introduction
A patient who has been operated on under general anesthesia comes to the recovery room for further monitoring after surgery. There, ECG, blood pressure, pulse and oxygen saturation (vital signs) as well as the patient’s general condition are monitored. The patient remains in the recovery room until he or she awakens from the anesthesia and his or her vital signs are stable enough to be transferred to the ward. General anesthesia can lead to some after-effects and complications after surgery, which are explained in more detail below. Overall, potential complications can be quickly and reliably detected by modern monitoring methods, and in most cases can be treated well.
Possible consequences of general anesthesia
A very common side effect after general anesthesia is nausea with vomiting (PONV = postoperative nausea and vomiting). This occurs in about 20 to 30% of all patients. There is an increased risk in women, children, non-smokers, if the anaesthesia lasts for a long time (more than 2 hours), if opioids are administered postoperatively or if inhalation anaesthetics (including flurans) are used.
If the patient suffers from motion sickness, this also makes the occurrence of nausea and vomiting likely. The risk of PONV can be assessed on the basis of the risk factors mentioned above. For this purpose, the so-called apple score is often used, which takes some of the risk factors into account.
If the risk is very high, inhalation anesthetics should be avoided and prophylactic medication should be used. In addition to dexamethasone, 5-HT3 antagonists (Sertrone), histamine H1 antagonists (dimenhydrinate) and the neuroleptic droperidol are suitable for this purpose. For the therapy of postoperative nausea with vomiting, the above-mentioned substances can also be used in addition to dexamethaosn (due to its delayed onset of action).
However, in contrast to prophylactic therapy, they are administered in lower doses. In some cases, a narrowing of the airways may occur after waking up. Especially smokers or people with pre-existing lung diseases such as asthma or COPD can suffer a spasm (cramping of the muscles) of the bronchi.
If the narcotics have a longer effect (so-called overhang), the respiratory drive can be reduced. Through consistent monitoring and the administration of bronchodilator substances, the narrowing of the bronchi can be reversed. As a reaction to the exertion of the body through surgery and general anesthesia, the blood pressure can be both too high and too low.
Patients with heart disease may experience rhythm disturbances up to a heart attack after general anesthesia. In order to counteract possible complications of existing heart diseases, these patients are also monitored particularly closely with an ECG after general anesthesia. The muscle tremor is also called shivering.
The anesthesia cancels out the heat regulation of the human body. In addition, a lot of body heat is lost through the open surgical field. Therefore, patients are warmed up during longer, larger operations during the operation.
After the operation, the brain areas of the temperature control notice a discrepancy to the normal state. Therefore, muscle trembling for rewarming is one of the more common after-effects of anesthesia. One of the problems with muscle tremor is the movement of the body, which can increase pain.
On the other hand, the body needs a lot of oxygen for the process, which can lead to a reduced supply of oxygen to the organs. This can be dangerous for patients with pre-existing heart disease, which is why they are often not awakened until a normal body temperature is reached. In order to generally counteract the occurrence of muscle tremors, patients are warmed up further in the recovery room.
If this does occur, the anesthetist (anaesthetist) can break the tremor with drugs (e.g. the opioids pethidine or clonidine). Some patients react particularly sensitively to the anaesthetics and therefore need longer to wake up. The narcotics can be weakened with antagonists (substance that counteracts the anaesthetic) to speed up the process.
Tiredness after general anesthesia is completely normal and not a cause for concern. On the other hand, some patients are very agitated after awakening. One reason for this can be post-operative pain, which can be suppressed with painkillers.The excitement that results from the surgical procedure can also be responsible for the restlessness.
In the context of post-operative delirium, which often occurs in older patients, the patient may in very rare cases develop sleep disorders that last for several days. Due to a general restlessness, patients report sleep disorders. Regular waking up at night is common.
As a rule, the symptoms recede within a few days to weeks. If there is no improvement, the normal sleep-wake rhythm can be disturbed by the anaesthesia to such an extent that medication is required to treat the sleep disorder. A rather rare after-effect of general anesthesia is headache.
As a rule, headaches are not caused by the side effects of the medication, but can occur due to incorrect positioning of the patient during or a lack of fluid after the operation. Headaches often occur with regional anesthesia (spinal/epidural anesthesia). Headaches are also usually not of long duration.
If necessary, pain therapy (e.g. with paracetamol or ibuprofen) may be required to relieve the pain. Postoperative delirium is a state of mental confusion that can be accompanied by anxiety and hallucinations. On average, it takes seven days for the delirium to subside, in some cases it can take up to a month.
Mainly older patients are affected. It is controversially discussed whether the anesthesia or the surgical intervention itself is responsible for the development of delirium. Assured risk factors are, in addition to old age, brain damage caused by dementia, serious diseases and long operations.
The delirium can be treated with medication. A frequent after-effect of anesthesia is confusion. This occurs in the context of a so-called postoperative delirium or transitional syndrome.
Older people (older than 65 years) are particularly affected. There are two different forms of postoperative delirium, a central excitatory (arousal) and a central depressor (attenuation). In addition to confusion, the central-excitatory form can cause general restlessness, hallucinations, movement disorders and seizures, whereas patients in the central-depressor form mainly show delayed waking with drowsiness.
In addition, patients in both cases are often disoriented in time and place. The occurrence and duration of the symptoms vary from patient to patient. While in some patients the above-mentioned symptoms occur immediately upon awakening, in others they may manifest themselves only after a few hours, days or weeks.
The duration of the symptoms also varies greatly and ranges from days to weeks. In rare cases, the confusion can last for several months. Usually, however, there is an improvement in the home environment.
Another after-effect that can occur in addition to confusion in the context of a postoperative delirium is forgetfulness. Patients are often disoriented in time and place after general anesthesia and also show weaknesses in concentration. This symptomatology occurs mainly in older patients (older than 65 years).
The time of occurrence and the duration of the forgetfulness vary greatly from patient to patient. In rare cases, the symptoms can persist for months. However, it should not be confused with dementia.
There is no direct connection between general anesthesia and increased hair loss. Nevertheless, many patients report increased hair loss in the days following surgery. The hair loss can occur due to increased physical strain during the operation.
The stress leads to a reduced supply of oxygen and nutrients to the hair roots and consequently to a disturbed growth with hair loss. The exact mechanisms are not yet understood. As a rule, the hair regenerates even within a few days after an operation.
In very rare cases, hair loss also occurs as a side effect of the administration of some anaesthetic drugs. Hair loss in menNumerous anaesthetic drugs show effects on blood pressure.The most commonly used anesthetic Propofol, for example, leads to a slight dilatation of the vessels (vasodilatation) and a reduction in cardiac output, resulting in a drop in blood pressure. Conversely, in very rare cases, however, high physical exertion with the release of stress hormones can also lead to increased blood pressure. For these reasons, the monitoring of vital parameters (blood pressure, heart rate, O2 saturation, breathing rate) is also carried out during general anesthesia. The symptoms of lowered or raised blood pressure usually subside within a few hours or days after general anesthesia.
