NEUROTICS ACTING ON THE BRAIN AND PRODUCING INSENSIBILITY.
CHLOROFORM—CHLORAL—BICHLORIDE OF METHYLENE—ETHER—AMYLENE—NITROUS OXIDE.
The anæsthetics which have hitherto been employed in the practice of medicine are chloroform, sulphuric ether (or a mixture of these), bichloride of methylene and nitrous oxide, and amylene. Any of these agents may cause death when introduced into the system by inhalation.
Chloroform is a colorless, heavy, volatile liquid; having a fruity ethereal odor and a sweet pungent taste. It is formed by the union of chlorine and marsh gas, but more commonly by the action of bleaching powder on ethylic or methylic alcohol. It is readily soluble in alcohol, but very sparingly so in water. Chloroform is a good solvent of caoutchouc, gutta-percha, camphor, wax, resin, some of the alkaloids, &c.
The symptoms produced by the vapor of chloroform may be divided into three groups of varying intensity; briefly they are these: First, a degree of relief from pain, the senses being but slightly affected; second, a stage of excitement and incoherence, wherein the patient is prone to struggle; and thirdly, a stage of which the most marked features are complete insensibility and narcotism, with relaxation of the muscular system. At first the patient is conscious of all that is passing around him, but there is dizziness and singing in the ears. Then the mental functions are impaired, there is often excitement, the saliva is increased, the patient pushes away the inhaler, rigidity and spasms of the muscles may occur, and there is incoherent talk. In the next stage there is insensibility to pain, and the conjunctiva may be touched without causing flinching. If the use of this anæsthetic be pushed further the breathing becomes stertorous, the muscles quite relaxed, and the pupils dilated; while a still further increase of the chloroform embarrasses and then stops the breathing and arrests the heart’s action.
Many cases of death from the vapor of chloroform have occurred, the fatal effect sometimes happening very rapidly from shock, syncope, or convulsions. The vapor of only thirty drops has destroyed life in one minute. Death under the influence of chloroform must not be confounded with death from its effects. The smallest fatal dose when the drug has been swallowed is one drachm in a boy aged four.
The effects of chloroform taken by the mouth are of the same description as those which follow the inhalation of this agent; with this exception, that the fatal result seems to be longer deferred. A case reported in the Medical Times and Gazette, 10th May, 1862, illustrates the symptoms, &c., in a clear way. Mr. M., thirty-four years of age, a highly-gifted restless man, was in the habit of inhaling chloroform on account of sleeplessness. He was very sensitive to its action. At about 12.30 A.M. on the 7th October, 1861, he drank some chloroform; the quantity being uncertain, though it may be inferred that it was about one ounce. At 7.15 he was in such a profound sleep that his wife felt uneasy, and she sent for Dr. Axel Lamm. This gentleman found his patient in a tranquil sleep, the respiration being somewhat hurried and audible, the pulse full but slow, the body warm, and the pupils dilated and insensible. There was a perceptible smell of chloroform in the breath and in the air of the room. The window was opened, ice was applied to the head, cold affusions were used along the spine, and an enema was administered. At 9.30 A.M., the patient was paler, breathing less audibly, and with a weaker pulse. Artificial respiration was employed by means of electricity, an ammonia lavement was given, and aspersions of iced water to the chest and pit of the stomach were used alternately with warm coverings. The stupor continued, the respired air smelt distinctly of chloroform, the abdomen was tympanitic, and the pupils began to contract. About 9 P.M. the eyes began to move, the pupils seemed sensible to light, the pulse was 160, there was abundant perspiration, and the patient sat up for a few moments and looked surprised. Exhaustion, however, set in, and death occurred just before midnight, nearly twenty-four hours after swallowing the poison.
A second interesting case (Medical Times and Gazette, 31st May, 1862) also deserves attention. A gentleman, fifty years of age, swallowed two ounces of pure chloroform at 8 A.M. He was not seen until 3 P.M., when he was found in a state of deep coma. His breath smelt strongly of chloroform, the pupils were widely dilated and insensible, the pulse slow and feeble, the surface colder than natural, the movements of the thorax scarcely perceptible, and sensation generally abolished. Ammonia, sinapisms, bottles of hot water, and cold affusion did no good; but on using a stomach-pump a quantity of chloroform mixed with watery mucus was withdrawn, and in less than an hour the patient was able to answer questions. For three or four days he complained of a burning sensation in the throat and epigastrium, and then got well. A consideration of the treatment employed in this instance cannot but suggest the idea that the first patient might have had a better chance of recovery had the stomach-pump been used when Dr. Lamm was first called in; though it is difficult to conceive how any quantity of chloroform could remain in the stomach for seven hours, without all of it being absorbed.
Various plans have been suggested for the administration of chloroform with safety, but this must be remembered: the use of anæsthetics is at all times attended with risk, and we can only at best diminish the danger. Apparatus may be used so as to reduce the risk to a minimum; but this is plain, any contrivance which in itself requires much attention, and thereby diverts it from the patient, is bad. More lives have been lost by bungling in its administration than from the noxious character of the drug.
In the treatment of poisoning by the vapor of any of the anæsthetics mentioned in this chapter, we must expose the patient to a current of pure air, use cold affusion, and employ artificial respiration until the poison is eliminated. Galvanism may be employed to keep up the action of the diaphragm, either directly or through the phrenics. As these agents are got rid of through the lungs, the purity of the expired air is one test of the elimination being complete; though of course inferior to the evidence afforded by the subsidence of the symptoms. In poisoning by liquid chloroform or ether the stomach-pump ought to be promptly used.
Chloral Hydrate, which with an alkali is converted into chloroform, has of late been much used as a narcotic and for easing pain. No details of any case of poisoning by its agency have yet been published.
Bichloride of Methylene has been used for anæsthetic purposes. It is supposed to be safer than chloroform. Practically they act much alike, and death happens with the one as with the other.
Test.—Chloroform at a red heat is decomposed, and chlorine and hydrochloric acid are formed. Hence, to detect it the substance supposed to contain it may be heated so as to expel the chloroform, which should be conducted away from it by a tube at right angles; to this heat should be applied sufficient to decompose the vapor, and its products searched for by the ordinary tests. The smell is a valuable criterion.
Sulphuric Ether.—Sulphuric ether, or ether, is a clear colorless liquid, very inflammable, soluble in alcohol, and less so in water. It is usually obtained by distilling common alcohol with sulphuric acid.
The effects produced by the inhalation of ether are similar to those which result from chloroform. It is, however, without doubt a much safer agent, but its effects are longer in manifesting themselves; it is more irritating to the air-passages, and much more of it is required. Deaths have occurred under its influence as under that of chloroform.
Amylene.—This is a colorless, volatile liquid, made by distilling amylic alcohol (obtained from crude fusel oil, or oil of potato spirit) with chloride of zinc.
Dr. Snow found that amylene, like chloroform, is capable of causing sudden death by inducing over-narcotism of the heart, and paralysis of this organ. He had two deaths from it, and it has since been entirely given up as an anæsthetic.
Nitrous Oxide.—Comparatively recently the laughing gas of Sir Humphrey Davy has been introduced as an anæsthetic agent. Its successful use depends on the total exclusion of air from the lungs during its exhibition. It can only be used for a short time, hence it is chiefly employed in dental operations, although it has been given for a considerable length of time consecutively by allowing the patient to return to the verge of sensibility before giving a fresh dose.