On December 10, 1844, the dentist H. Wells visited in Hartford, USA, the idea of a traveling theater in which volunteers could inhale nitrous oxide (nitrous oxide) as a special attraction. During the performance, Wells observed that one of the subjects contracted a gaping lower leg wound without showing a painful reaction. The next morning, Wells, who had intuitively recognized the tremendous importance of this process, had a wisdom tooth drawn under nitrous oxide; he felt no pain.
Development of anesthesia
Five weeks later, he made his discovery public after convincing himself of the effectiveness of the gas in many patients: he wanted to perform a painless tooth extraction at Boston General Hospital. The attempt failed, Wells was booed. In 1848 he committed suicide - as a broken man. But the development of anesthesia was unstoppable.
In the same place where Wells had failed, in October 1846, W. Morton, a former collaborator of Wells's, had the first clinical anesthesia with ether. In 1847, J. Simpson introduced chloroform as anesthetic in Edinburgh. A few years later, all operating theaters in the world underwent surgery only under anesthesia.
The term "narcosis" derives from the Greek word "narce" ("rigid"). Anesthesia is caused by paralysis of parts of the central nervous system
- the pain sensation
- the defense reflexes
- the muscle tension
reversible, that is temporary, switched off. General anesthesia therefore requires a combination of various medications: sleeping pills, painkillers, muscle relaxants (muscle relaxants), and antireflective agents. The condition thus achieved is characterized by deep sleep and pain insensitivity. In contrast to general anesthesia, consciousness remains intact in partial anesthesia. In this form of anesthesia, only a part of the body becomes numb and thus insensitive to pain.
For a long time, 4 anesthetics (Guedel) were the basis of the anesthetic guide. Meanwhile, however, they have lost importance. The anesthesiologist's modern combination anesthesia is based on other clinical signs, including blood pressure and pulse behavior, skin condition (sweating, blood circulation), muscle tone and eye signs (eg, tearing).
During general anesthesia, the anesthetists must therefore constantly check the "vital signs" of the patient. So you always know if the heart is working properly (ECG is running permanently, blood pressure and pulse are permanently measured), if enough oxygen in the blood is (is permanently measured), if the lungs are working well (ventilation pressure is permanently measured).
Older and younger brain regions
Especially the breathing and the heartbeat - so our vital functions work even under anesthesia quite well. In contrast, the consciousness is completely turned off. How is that possible? That anesthesia is feasible at all, based on the fact that our brain has developed a different development. To survive, a central nervous system first had to develop.
It was only at a much later date that consciousness and intellect formed in our brains. During anesthesia, the younger regions of our brain are the first to be switched off, and older brain regions with the corresponding functions are still largely active.