CHLORAL HYDRATE
This substance is prepared by acting on alcohol by chlorine. It is used extensively as a hypnotic, and, owing to its indiscriminate use, many fatal cases have been recorded. Care should be taken when large doses are given not to repeat them too quickly, as there appears to be a tendency to accumulation, and sudden and dangerous action of the drug.
Symptoms.—Chloral, in moderate doses, acts on the brain as a powerful hypnotic, the early symptoms being gradual drowsiness, followed by deep sleep. With a dose of about 30 grains, the patient can, however, by walking about, ward off sleep. In large doses the narcosis becomes completely uncontrollable, and the poison then acts as a depressant to the basal ganglia of the brain, and on the spinal cord; and, as a result, there is weakness of the heart‘s action, with ultimate diastolic arrest, slowing of the respiratory movements, and general muscular weakness, with some anæsthesia. Under these circumstances the patient has all the appearance of a drunken person, the face is flushed, and the deep sleep may pass imperceptibly into death without any marked change. In some cases delirium precedes the condition of sleep. The pulse in some cases is quickened, and the face flushed; but, in other cases, the pulse becomes slow and almost imperceptible, the heart being ultimately arrested in diastole. In these cases the face is pale, and the breathing performed at long intervals. The motor paralysis present, when a poisonous dose is taken, is due to the action of the drug on the spinal cord, and not on the nerves. During the sleep produced by chloral, the pupils are contracted, but dilate on the person awakening. In a case described by Dr. Levinstein, and reported in the Lancet, 21st February 1874, the patient took six drachms with intent to commit suicide. The face was at first flushed, the veins swollen, and the pulse 160 per minute; he then became livid, the pupils contracted, and at times the circulation appeared to be entirely arrested. The temperature varied from 32.9° C. to 38.7° C. (89.6° F. to 100.4° F.). This case recovered under treatment by the subcutaneous injections of strychnine (.03 to .04 grain), and the use of faradisation in thirty-two hours after the poison had been taken. Chronic chloral poisoning, “chloral-drinking,” has unfortunately become far too common of late years, in which the mental faculties suffer severely, so that in our asylums, cases of mania and melancholia are rightly (or wrongly) attributed to the habit. A peculiar eruption, not unlike that produced by shell-fish, and followed by desquamation, sometimes occurs when this substance has been given for some time in medicinal doses.
Post-mortem Appearances.—These are not unlike those of asphyxia, the vessels of the brain being engorged, and the ventricles containing an abnormal quantity of fluid. The mucous membrane of the larynx may be injected, and in some cases œdematous. The right side of the heart is engorged and the left empty, together with congestion of the lungs. Chloral is very little decomposed into chloroform by the blood. W. H. Roberts has in several cases recovered it as chloral from the blood.
Fatal Dose.—The fatal dose cannot be accurately stated, but children, as in the case of belladonna, are said to bear the drug better than adults. A child a year old died in ten hours from a dose of three grains. Ten grains proved fatal to an old lady seventy years of age. Twenty grains has caused death in an adult in half an hour, and in one case thirty grains. As a rule, any quantity over two drachms may be considered a dangerous, if not a fatal dose, although recovery has been stated to have occurred after one ounce. Dr. Richardson considers 120 grains, distributed over twenty-four hours, as a safe dose for an adult. Death may take place suddenly, or after the lapse of several hours.
Fatal Period.—From fifteen minutes, which is the shortest time on record, to thirty-nine and a half hours, which is the longest period recorded.
Chemical Analysis.—Chloral may be extracted from the stomach contents by digestion with absolute alcohol acidified by sulphuric acid. The alcoholic extract is filtered and evaporated. The residue is treated with petroleum ether to remove fatty substances, and finally shaken with pure ether to remove the chloral. On evaporating the ether the chloral hydrate is left. From urine it may be extracted by first acidifying with sulphuric acid and then treating it with petroleum ether and ether. Chloral hydrate in solution gives the following reactions:—
1. On agitation with solution of caustic potash, and gently warmed if necessary, chloroform is evolved, which can be detected by its odour. From a strong solution the chloroform may separate in the form of minute globules.
2. If one drop of ammonium sulphide be added to a solution of chloral hydrate and gently heated, a peculiar opalescent milky reddish-yellow precipitate forms. This test is extremely delicate, and differentiates chloral hydrate from chloroform.
3. Alcoholic solution of potash and aniline when added to chloral hydrate solution, shaken up and warmed, produces the peculiar odour of phenyl-isocyanide. This is due to the formation of chloroform on the addition of the caustic potash.
4. If β-naphthol dissolved in caustic potash solution be added to a solution of chloral hydrate and the mixture warmed, a blue colour is produced.
5. Chloral hydrate reduces Fehling‘s solution.
To separate chloroform in the stomach contents from chloral hydrate they should be acidified with tartaric acid and distilled, when the chloroform which was free in the stomach will pass over to the receiver. If the residue be now rendered alkaline with caustic potash and again distilled, any chloroform which then comes over must have been derived from chloral hydrate in the stomach contents.
Treatment.—The treatment consists in washing out the stomach, the administration of emetics, or hypodermic injection of apomorphine, in the use of galvanism, friction, mustard-plasters to the calves of the legs, artificial respiration, and the hypodermic injection of a solution of nitrate of strychnia or injection of atropine. The warmth of the body must be carefully maintained in all cases by suitable external applications. Oxygen inhalations are said to be beneficial.