Effects and Types of Anesthetics
Anesthetics are depressant drugs that cause a total or
partial loss of the sense of pain. The effect an anesthetic has
on the body depends on several factors. What type of anesthetic
is used determines the effect along with the dosage and a person
(or animal’s) body weight.
The word anesthesia was first introduced by Oliver Wendell
Holmes in 1846 about four weeks after the first demonstration of
ether anesthesia at the Massachusetts General Hospital. Ether
was the first type of anesthesia used and was demonstrated as a
means of allowing a patient to be unconscious and free from
Stages of Anesthesia
Stage one is known ...view middle of the document...
Types of Anesthesia
Though ether was the first type of anesthesia, there are now
many different types. Ether, along with chloroform, are known as
the anesthetics from hell because they have all of the negative
traits of this class of drugs. Ethyl ether is potent and fairly
safe, but it is also flammable and explosive. It forms peroxides
and it produces a very unpleasant induction phase. Also, it is
irritating and causes nausea and vomiting during recovery.
Chloroform is just as potent and relaxes the skeletal muscle
fairly effectively, but has a narrow margin of safety, produces
liver and kidney toxicity, and has been known to fairly
frequently cause cardiac arrest. In addition, it can also cause
Another type of general anesthetic agent is non halogenated
hydrocarbons. All of these work well and the longer the chain,
the higher the potency. However, these have a tendency to
produce cardiovascular toxicity. Cyclopropane is the only one
still in use and is explosive.
Ethyl ether was the first anesthetic, but is not used
anymore because of its negative effects, but other ethers came
along throughout the past century and a half as well. Like
hydrocarbons, the longer the chain, the more potent the
anesthetic. However, the longer the chain, the higher the
toxicity. Also having a longer chain reduces induction time.
Ethyl ether is very rarely used and divinyl ether is explosive
and produces deep anesthesia too quickly.
Another type of general anesthetic is halogenated
hydrocarbons. When a halogen is added to an anesthesia,
flammability is greatly reduced, and in some cases, eliminated.
In addition, the halogen can also add potency. Depending on the
halogen, some of these compounds can cause arrhythmia and/or
renal or hepatic toxicity. Compounds containing only bromine are
usually not useful and compounds containing only chlorine are
limited in use, are toxic, and can cause arrhythmia. The best of