PENTAL.—Pental (trimethyl-ethylene or beta-iso-amylene) is a colorless, in flammable liquid, insoluble in water, but miscible in all proportions with alcohol, ether, and chloroform. It does not de compose on exposure to light and air. It was discovered and described by Balard in 1844 and used in 1856, after which it dropped out of sight. Toward the end of 1891 it was resurrected by von Mer ing, and its use advised as an amnsthetic for dental and minor surgical operations, in doses of 2 to 3 drachms by inhalation, or applied as a spray for local anesthesia.
Physiological Action of and Poisoning by Pental.—Pental is, according to the experiments of Wood and Cerna, a dan gerous cardiac depressant, and therefore a most dangerous anmsthetic. symptoms—such as excitability, tremors, difficulty of speech, headache, erythem atous eruptions, and even convulsive movements—have been reported as se quelm of pental anmsthesia. Albumin, casts, and blood have been found in the urine after its use. Temporary cessation of respiration with cyanosis is not in frequent during its administration, and Cheyne-Stokes respiration has been ob served. The circulation has been much embarrassed through its depressing ac tion upon the heart, and death has ensued from respiratory and cardiac paralysis.
Treatment of Poisoning by Pental.— The treatment of poisoning by pental is similar to that of chloroform poison ing. If the drug has been swallowed, the use of an emetic or stomach-siphon to evacuate the stomach and subsequent stimulation are indicated. If pental has been inhaled, with the first dangerous symptoms it should be instantly discon tinued and fresh air admitted. Water may be dashed on the face, the tongue pulled out, artificial respiration prac ticed, the galvanic current applied, and an hypodermic injection of grain of strychnine given, as quickly as possible. Death by this agent is often so rapid that treatment is of no avail.
Therapeutics.—The principal use of pental is that of producing general anaes thesia, especially for short operations. It is only mentioned in this work to em phasize its dangers and to emphatically condemn its use as an anaesthetic. Prince Stallard has shown that the fatality of this agent has been 1 out of every 164 administrations. T. J. Walker has rightly protested against its further employment, this proportion of deaths being one hun dred times greater than that of any other anesthetic.