In modern medicine, anesthesia describes, on the one hand, the state of insensitivity sought to perform surgery and, on the other hand, the method itself to bring about this condition. For this purpose, special pain and consciousness-inhibiting drugs, called anesthetics, administered. Under general anesthesia or local anesthesia, interventions can be made on the patient in this way, which were previously unimaginable.
Function of anesthesia in intensive care
The most common anesthetic form is general anesthesia, which is also called anesthesia. It acts on the entire body and serves the painless completion of surgical procedures. The state of anesthesia is achieved by the intravenous or inhaled administration of drugs (anesthetics) and is characterized by loss of consciousness, containment of certain areas of the nervous system, muscle relaxation and the elimination of pain sensation. Normally, patients have memory lapses when they wake up from anesthesia. In this context, one speaks of amnesia.
Local anesthesia (regional anesthesia) is a procedure for local anesthesia. The aim is merely the elimination of pain by medicinal action on the nervous system. The patient's sense of consciousness remains unaffected in local anesthesia.
Typically, local anesthesia is via an injection in the area of the spinal cord, as is the case with epidural anesthesia or spinal anesthesia. For this purpose, a surface anesthetic is usually carried out by applying ointments, gels, sprays or patches to the skin.
First steps of anesthesiology
As early as the Middle Ages, priests and monks used prayers as well as alcohol and pain-relieving plants as part of their healing practices. In addition, there were a number of unsound techniques for numbing pain during a treatment. These included, for example, bleeding or compression of blood vessels to numb specific limbs. This method was very dangerous because it could lead to infections and even loss of consciousness.
Despite the initially crude methods, anesthesia has always pursued only one goal: the painlessness of the patient in medical interventions. For this one knew early on the anesthetic effect of plant extracts to use. Some herbal substances such as curare or opium (morphine) are still used today in anesthetics.
Beginnings of inhaled anesthesia
In the early modern period, science gained new knowledge about gaseous particles. This knowledge was also used in anesthetics and intensive care. A new method of anesthesia was the administration of gaseous anesthetics by inhalation through the lungs of the patient. A disadvantage of inhaled anesthesia, however, was the slow accumulation of the gas in the organism. In addition, the body needed just as much time to recover from the anesthetic. Nitrous oxide, chloroform and ether were the first gaseous anesthetics used in anesthesia.
Nitrous oxide was one of the first gaseous substances, which was first consumed as intoxicants and pleasure. At the end of the 19th century, first attempts were made to use nitrous oxide as an anesthetic in dentistry.
Chloroform was mainly used in obstetrics. However, chloroform has a very toxic and highly explosive property, many of which have died.
Advantages and disadvantages of ether as anesthetic
Already in low concentration could be achieved with ether sufficient pain elimination. In the narcotic dose of this anesthetic, there was a muscle relaxation of the patient, but without severe respiratory depression. This created good operating conditions during anesthesia.
Although ether as an anesthetic was less dangerous than chloroform, this anesthetic drug also had health-damaging properties. Anesthesia with ether caused severe irritation to the patient's airways. In addition, the newly discovered gaseous anesthetic triggered vomiting and severe coughing. In the worst case, inhalation of ether induced anesthesia could lead to respiratory arrest.
Nevertheless, in 1846, the first successful Aether narcosis in history was performed for the treatment of a lower-jaw tumor in Boston. Only a few months later, ether was also used in London as an anesthetic during a thigh amputation. Since then, ether has become known as an anesthetic for inducing inhalation anesthesia worldwide.
The administration of analgesic drugs via the vein has been known since the invention of the syringe, well before the development of anesthesia. Already in the 17th century, intravenous anesthesia had been tested on dogs with opium. Nevertheless, intravenous anesthesia for pain elimination was not introduced to medicine until 1946.
Advantages of intravenous anesthesia:
Gaseous anesthetics have the property of eliminating all four components of anesthesia, namely, awareness, pain, muscle activity, and the vegetative stress reactions simultaneously. Therefore, the inhaled anesthesia, ie the narcotization of the patient by inhalation of gases such as nitrous oxide, chloroform or ether, was difficult to control.
The intravenous method of modern anesthesia makes it possible to turn off each component individually. This allows the administration of anesthetic drugs to be tailored to the patient. Thus, the implementation of anesthesia is greatly facilitated.
Anesthesia procedure today
With the inclusion of the "specialist in anesthesia" in 1953 in the Medical Occupational Code in Germany, the official recognition of anesthesia as an independent medical specialty. Many of the opiates and hypnotics that have been introduced over the next few years, such as fentanyl, bupivacaine, midazolam, sevoflurane, remifentanil and propofol, are now important anesthetics for critical care and pain therapy.
The development of synthetic drugs today allows specialists and anaesthesiologists to precisely dose anesthetics. Dangerous incidents during surgery become increasingly rare.
Meanwhile, anesthesia has progressed so far that medical interventions can be performed painlessly. If you had to put a tracheotomy at times to initiate an inhaled anesthetic, nowadays the breathing tube is inserted directly into the mouth or nasal cavity. This method is not only gentler, but also associated with a lower risk of infection.
Anesthesia is still interested in expanding its narcosis procedure for the benefit of the patient. Nevertheless, every anesthetic involves a risk. Therefore, you should consider the following rules:
- Be sober before any narcosis.
- Follow the instructions of the anesthetist.
- Read the information sheet of your anesthetist carefully.
- Tell your anesthesiologist about possible (pre-) diseases of the cardiovascular system or infections.
- Do not expose your body to narcosis unless it is medically necessary.