General Anesthetic Drugs sic, an injectable anesthetic, a short-acting muscle relaxant, and a low dose of a neuroleptic. In regional anesthesia (spinal anesthesia) with a local anesthetic (p. 204), nociception is eliminated, while consciousness is preserved. This procedure, therefore, does not fall under the definition of general anesthesia. According to their mode of application, general anesthetics in the restricted sense are divided into inhalational (gaseous, volatile) and injectable agents. Inhalational anesthetics are administered in and, for the most part, eliminated via respired air. They serve to maintain anesthesia. Pertinent substances are considered on p. 218. Injectable anesthetics (p. 220) are. | 216 General Anesthetic Drugs General Anesthesia and General Anesthetic Drugs General anesthesia is a state of drug-induced reversible inhibition of central nervous function during which surgical procedures can be carried out in the absence of consciousness responsiveness to pain defensive or involuntary movements and significant autonomic reflex responses A . The required level of anesthesia depends on the intensity of the pain-producing stimuli . the degree of nociceptive stimulation. The skilful anesthetist therefore dynamically adapts the plane of anesthesia to the demands of the surgical situation. Originally anesthetization was achieved with a single anesthetic agent . diethylether first successfully demonstrated in 1846 by W. T. G. Morton Boston . To suppress defensive reflexes such a mono-anesthesia necessitates a dosage in excess of that needed to cause unconsciousness thereby increasing the risk of paralyzing vital functions such as cardiovascular homeostasis B . Modern anesthesia employs a combination of different drugs to achieve the goals of surgical anesthesia balanced anesthesia . This approach reduces the hazards of anesthesia. In C are listed examples of drugs that are used concurrently or sequentially as anesthesia adjuncts. In the case of the inhalational anesthetics the choice of adjuncts relates to the specific property to be exploited see below . Muscle relaxants opioid analgesics such as fentanyl and the parasympatholytic atropine are discussed elsewhere in more detail. Neuroleptanalgesia can be considered a special form of combination anesthesia in which the short-acting opioid analgesics fentanyl alfentanil remifentanil is combined with the strongly sedating and affect-blunting neuroleptic droperidol. This procedure is used in high-risk patients . advanced age liver damage . Neuroleptanesthesia refers to the combined use of a short-acting analge sic an injectable anesthetic a short-acting muscle relaxant and a low dose of a .
