Anesthetic, definition

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... 

Although still used medically, at one time elher was ihe major anesthetic, for which it must be scrupulously pure In addition lo various side effects which may result from the use of ether as an anesthetic, it is a definite hazard in the operating room because of its explosive properties, particularly in enriched oxygen atmospheres. 

Nonreceptor-Mediated Drug Action. At least one important class of drugs, the general anesthetics, has been assumed not to owe its therapeutic activities to a specific receptor process. Anesthetic potency shows an excellent linear correlation with partition coefficient and this has been extrapolated to a definition of action at a lipid site. The phospholipids of cell membranes, particularly nerve cells, have been considered as principal targets for general anesthetic action. It has been hypothesized... 

The standard safety margin has definitive advantages over therapeutic ratio. In contrast to the LD50/ED50 index, the standard safety margin is influenced not only by the distance between central points of the anesthetic... 

The tri-chlorine substitution product of methane is the common and very important anesthetic chloroform. It may be made by the method referred to, viz., by the direct chlorination of methane. This method is not, however, a practical one. The industrial preparation is from alcohol or acetone, by treatment with chlorine and an alkali. In the reaction with alcohol the chlorine acts, first, as an oxidizing agent, oxidizing the alcohol to aldehyde. The chlorine then acts as a substituting agent forming a tri-chlorine substitution product of the aldehyde. This tri-chlor aldehyde is then decomposed by the alkali and chloroform results. The steps in this reaction have been definitely proven, as follows ... 

In a careful meta-analysis, 29 randomized, controlled studies of the incidence of transient radicular irritation were identified (243). Lidocaine and mepivacaine were identified as the two local anesthetics that most commonly cause transient radicular irritation, while prilo-caine, bupivacaine, and ropivacaine had the lowest incidences. Owing to insufficient data, definitive statements could not be made about the effects of the baricity of the local anesthetic, the concentration, and the effect of vasoconstrictors, although all these factors seemed not to be relevant. With regard to intrathecal ropivacaine, the incidence in the formal studies was zero. However, there has been one previous report after intrathecal administration, and one report of transient radicular irritation following epidural anesthesia with ropivacaine the symptoms resolved within 24 hours (244). 

Jaundice after general anesthesia in which nitrous oxide was the only anesthetic has been described (36). However, contamination with halothane was not definitely ruled out. 

Some experimental data have suggested a possible teratogenic potential of nitrous oxide, the clinical relevance of which is unclear (41). The interaction with vitamin B12 causes changes in DNA synthesis that could be important in the first trimester of pregnancy. Nitrous oxide is the only inhalational anesthetic that has definitely been... 

Ellis and Krantz, using Macacus rhesus monkeys, administered 8 g. of mannitol per kilo of body weight by stomach-tube. Three hours later the animals were anesthetized with sodium pentobarbital and two or three portions of the liver were taken from different lobes of each animal for individual glycogen determinations. In four animals used as controls, the mean liver-glycogen value was 0.28 percent with mannitol, in six animals, the value was 0.53 percent. This is not a definitely significant increase considering the wide variations in the control values. Sorbitol under the same conditions gave a mean value of 0.72 percent. 

As noted under the heading of general anesthetics, there are other allosteric sites that recognize re.spectively. neuro-.stcroids. barbiturates, inhalation anesthetics, alcohols and the phenol Diprivan (.separate sites). The convuLsants picro-toxin and pcntylenetetrazole have definite binding sites on GABA receptors. 

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