Side effects of anesthesia
The side effects of anesthesia can manifest themselves in many different ways and depend on many other factors. If complications occur during or after an operation, this is not necessarily due to the anaesthetic procedure. The risk of complications during anesthesia depends, among other things, on the possible previous illnesses of the patient and is increased with increasing age.
Damage after the operation or mortality due to the anaesthesia itself is estimated at a very low percentage. Possible problems that may occur concern breathing, for example. Initially, inserting the hollow probe (tube) into the trachea can be difficult if swelling or bleeding obstructs the view of the structures.
In addition, so-called aspiration, i.e. the penetration of foreign bodies such as regurgitated or vomited leftovers of food into the airways, can occur. In this case they can be displaced, which means an acute danger of suffocation for the patient, or cause pneumonia afterwards. Nevertheless, aspiration is rarely fatal, as swallowed foreign bodies are removed endoscopically and antibiotic therapy can prevent later inflammation.
This topic might also be of interest to you: Mask anaesthesia If the anaesthesia is not deep enough or the irritation of the airways caused by intubation is too strong, a so-called bronchospasm can occur. In this case, the smooth muscles in the walls of the trachea and bronchi instinctively tense up, narrowing the airways. Patients with known lung diseases (e.g. asthma, COPD) are a particularly common group.
This is remedied by muscle-relaxing or bronchodilator drugs and increased ventilation pressures. Laryngospasm occurs when the muscles of the larynx become tense and the glottis is closed. Breathing is no longer possible and the consequences of a lack of oxygen threaten.
This complication is more likely to occur during the anaesthetic drainage, i.e. when the tube is removed from the trachea. Oxygen can be administered by means of mask ventilation, clogging secretions must be removed and in an emergency a muscle relaxant is used to relax the muscles of the larynx. Other possible complications affect the cardiovascular system.
Due to the effect of the anaesthetic, the blood vessels, among other things, become dilated, which can lead to a drop in blood pressure, and the heart beats at a lower rate. While this circumstance does not matter much to a healthy patient, a weakened patient with a pre-existing cardiovascular system can react very strongly to it. Treatment for a rapid drop in blood pressure includes fluid infusions to increase blood volume and drugs that constrict blood vessels.Any cardiac dysrhythmia that may occur is remedied with appropriate substances (antiarrhythmics).
Individual extrasystoles, i.e. additional heartbeats in a normal rhythm, are occasionally observed, but are no cause for concern. A greater risk is posed by heart attacks during the procedure, which are more likely to occur in patients with heart disease. The consequences of stress during surgery, blood deficiency and undersupply of the heart muscles can, in the worst case, lead to cardiac arrest, which requires immediate resuscitation measures.
In order to minimize the risk of this, prior drug treatment of pre-damaged patients and regular blood pressure monitoring are recommended. The condition feared by some people during an operation is “intraoperative alertness” (awareness), where the patient has memories of words or sentences or sensations such as pain, panic or fear afterwards. The frequency is estimated at 0.1-0.2% and in most cases existing memories are not felt to be a burden.
Only in isolated cases do serious psychological disorders occur as a result of this experience. The risk of such a state of alertness is increased with lower doses of anaesthetics with regard to any previous illnesses, prolonged respiratory tract protection, the administration of muscle relaxants, a technical defect in the equipment responsible, but also on the patient side the previous abuse of alcohol, drugs or sleeping pills. In order to exclude possible waking states, monitoring systems are already being used which register electrical brain activity and perceptual capacity of the hearing.
Allergic reactions are also considered a possible complication, but they rarely play a role. Most often muscle relaxants are the cause, but anesthetics, antibiotics or latex gloves can also trigger an allergic reaction. This can manifest itself as a simple reddening of the skin, narrowing of the bronchial tubes and an anaphylactic shock with circulatory collapse as a result.
The further procedure is limited to the removal of the triggering allergen and the administration of fluid and medication to stabilize the patient. A dreaded complication of anaesthesia is nausea and vomiting after anaesthesia, as it involves the risk of aspiration (inhalation) of vomit. If saliva or vomit is inhaled, infections of the respiratory tract can easily develop and patients must be monitored and treated.
Incidents have decreased in recent years thanks to new medical techniques and procedures, but can still occur today. The frequency rates of recent years are about one case of aspiration per 2000-3000 operations, with a slightly higher number of 1/1000 in pregnant women. A very rare complication is the so-called malignant hyperthermia.
This is an inherited disease that first appears when anaesthetics are administered and is considered life-threatening. It leads to an overactivation of the muscle fibers, which consume energy in an uncontrolled manner, which inevitably leads to an increase in carbon dioxide, a rise in temperature and hyperacidity in the body. Corresponding symptoms are muscle rigidity, tachycardia, and metabolic and organ failure, which ultimately leads to death.
If such a predisposition is suspected, tests can be carried out beforehand or triggering substances can be avoided. In an emergency, “dantrolene” is used, which has reduced mortality very drastically in recent years. This acutely life-threatening condition can only be remedied by immediately discontinuing the anaesthesia or replacing the causative medication. Other measures include cooling and close intensive medical monitoring. and after-effects of general anesthesia
