"DIAL" AS A SURGICAL ANAESTHETIC FOR NEUROLOGICAL OPERATIONS; WITH OBSERVATIONS ON THE NATURE OF ITS ACTION

¹ From the Laboratory of Physiology, Oxford

1. A liquid preparation of diallyl-barbituric acid, known by the trade name "Dial," is a satisfactory anaesthetic for major surgical operations on monkeys, cats and dogs. In monkeys there is a large margin of safety between the anaesthetic and the lethal dose.

2. For cats and dogs 0.5 cc. per kilogram intraperitoneally is adequate in the great majority of animals, but this may be increased to 0.65 without danger, and with any degree of anaesthesia ether can safely be used as a supplementary anaesthetic.

3. With monkeys 0.4 cc. per kilogram is adequate, but a dose of 0.6 can be used with safety.

4. Cats and dogs recover within thirty-six to forty-eight hours, monkeys within twenty to twenty-four hours.

5. The motor cortex in monkeys reacts to electrical stimulation even under profound "Dial" narcosis (e.g., 0.6 cc. per kilogram), and the anesthetic may therefore be used for class demonstration of the motor cortex.

6. "Dial" produces a state akin to normal sleep.

7. The site of action of "Dial" appears to be in the deep nuclei, chiefly in the hypothalamus and medulla.

8. In 100 surgical operations under "Dial" we have had only one fatality attributable to the anaesthetic.