General anesthetics choice

Diethyl ether was the inhalation anesthetic of choice during my childhood. Happily, 1 had rather little need of it. Ether was replaced years ago by a family of superior inhaled general anesthetics, most of which are ethane derivatives. The notable exception is another very simple molecule, nitrous oxide, N2O, frequently known as laughing gas. N2O has been around for a long time and was once a party drug. ... 

The next era in the history of depressants also involved the search for an effective anesthetic. William Morton was a Boston dentist and medical student who was familiar with Wells s blunder, but Morton learned of another drug that he believed might be a better choice as an anesthetic ether. Ether is a highly flammable liquid that vaporizes at room temperature. When the ftimes are inhaled, they produce a state of intoxication. After conducting some initial experiments with ether, Morton asked permission to demonstrate its use as a general anesthetic. In 1846, just a year after... 

Preexisting endocrine disorders such as hypothyroidism, hyperthyroidism, and diabetes melhtus should also dictate the choice of general anesthetics. In patients with hyperthyroidism, agents causing cardiac acceleration (atropine or sympathomimetic amines) should be used carefully. 

Lldoc ine. Lidocaine hydrochloride, an anilide, was originally introduced as a local anesthetic in 1943 and found to be a potent antiarrhythmic in 1960. The compound is a reverse amide of procainamide. Lidocaine is generally considered to be the dmg of choice in the treatment of ventricular arrhythmias and those originating from digitalis glycoside toxicity (1,2,15—17). 

Although most commonly used topical anesthetics are similar in onset, duration, and depth of anesthesia (see Chapter 6), several important differences exist. For diagnostic and treatment procedures requiring topical anesthesia, the clinician essentially has two choices tetracaine or proparacaine. Both provide rapid onset of anesthesia within 10 to 20 seconds and last approximately 10 to 20 minutes. If prolonged anesthesia is required, it may be accomplished by repeated application.Tetracaine may cause more discomfort upon instillation than proparacaine and typically results in more corneal compromise. In general, proparacaine 0.5% has a low incidence of hypersensitivity reactions and is the anesthetic of choice for topical anesthesia in ophthalmic applications. Other anesthetics that have occasional topical application are cocaine (4% to 10%) and lidocaine (4%). 

The choice of a chromatographic method may be dependent on the intended use. The appropriate method when the intent is to establish a general screen for inhalant abuse may be very different from the method chosen to monitor administration of a particular anesthetic or exposure to industrial chemicals in the workplace. Likewise, forensic applications may vary from a general screen to post-mortem quantitation of particular suspected VOCs in blood and tissues. The number of methods developed for specific purposes (or compounds) is beyond the scope of this chapter, but it is hoped that the information provided will assist the analyst in finding or adapting chromatographic methods suitable for their particular situation. 

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