Formula

(Ch3)2C.CH,Ch3, or C5H10.

Derivation

Pental is a tertiary amylene, obtained by heating amylene hydrate in presence of acids. It is a colorless liquid of specific gravity 0.6783 at 320 F., insoluble in water, but soluble in all proportions with alcohol, chloroform and ether. It is as inflammable as ether, and should therefore not be exposed to a flame. It boils at 100.40 F., or the latest preparation at 380 C, and burns with a luminous flame, and has a penetrating odor like that of mustard-oil.

Medical Properties And Action

Pental is a general anaesthetic and has been recommended by Dr. Hollander, of Halle, for minor surgical operations on account of no untoward effect being produced by it upon the tissues of the mouth and respiratory passages ; that unpleasant after-effects are exceptional; that consisting only of carbon and hydrogen, to the exclusion of the halogens, it therefore produces no evil after-effects. It is also claimed for pental that the anaesthesia comes on gradually without any previous conspicuous symptoms whatever; that the quickened pulse at the beginning soon returns to its normal state, and notwithstanding that the sensibility vanishes, consciousness in most cases partially remains. Under the profoundest narcosis from pental, it is asserted, that patients when requested will open the jaws, even though they were firmly closed before, and although they look at the operator with wide-open eyes, still they are unaware of what is being done with them. During the anaesthesia from pental and after, no disagreeable feeling, such as nausea, headache, etc., occurred in the experience of Dr. Hollander; and he claims that he never noticed any contraction of the muscles of the jaws and fingers, as is the case under bromide of ethyl, nor any depression of the chest or syncope, which sometimes result from chloroform and bromide of ethyl. He also asserts that he has administered pental to children from four to ten years of age, and to old people from fifty to sixty with the same results, and the least stage of excitement is very uncommon, the patient being always animated in a friendly, cheerful way, so that it could be termed laughing-ether. It is 32 also claimed that pental anaesthesia differs from chloroform in that it takes place more rapidly, and that there is no effect upon the action of the heart or respiration, and the administration in large quantities appears to be absolutely free from danger. Narcosis is produced by pental in from 40 to 45 seconds, and the rules and precautions in administering it are the same as for all other anaesthetics. Nervous and infirm patients require more of pental than the robust; and it is not always possible to determine when the anaesthesia is complete, as the corneal reflex remains somewhat long; and even though the raised hand should not fall back powerless, the anaesthesia may have occurred. Drs. H. C. Wood and D. Cerna, however, from experiments made with pental, arrived at the conclusion that pental will probably prove to be a dangerous anaesthetic, and if extensively used will produce death by cardiac arrest; and they also say that it is probable that the after-effects in the human being would be disagreeable, as they noticed in a dog a peculiar wild excitement directly after the anaesthesia had passed off. Pental is best administered by means of Junker's inhaler, which also weakens its unpleasant odor; the use of other apparatus occasions too much loss, as it is very volatile, and consumes more time. When taken up by the blood, pental is separated into two substances - water and carbonic acid. All apparel which impedes free breathing should be removed during the administration of pental, and the room be somewhat darkened.

Dental Uses

Pental is employed as a general anaesthetic in dental practice, principally for the extraction of teeth, and Dr. Hollander claims that in the case of a single extraction it is not necessary to wait for the disappearance of the corneal reflex, as it sometimes occurs rapidly, and at other times very slowly; and that the narcosis, although somewhat slower than bromide of ethyl, lasts longer, the duration being from three to seven minutes, and the time for its production one-half to two minutes. Dr. Hollander also claims that pental has produced anaesthesia when several other prominent agents have failed; but from the fact that unpleasant incidents have occurred during its use it should be very carefully administered.