Studies of Narcosis: Charles Ernest Overton Introduction

Abstract

It is unnecessary to describe the horror of surgery prior to the demonstration of ether anaesthesia at Massachusetts General Hospital in 1846. It was clearly a nightmare for patients and must have been little better for the medical personnel involved in so terrifying an undertaking. What is less obvious is that the introduction of anaesthesia accomplished far more than the abolition of intraoperative pain. The solution of the problem of pain enabled the evolution of virtually all of modern surgical therapeutics. Prior to this development, the major characteristic of a technically brilliant surgeon was speed the ability to do a below-the-knee amputation in less than a minute made or unmade reputations. Intra-cavitary surgery; operations in the chest, abdomen or skull were largly unthinkable and when attempted, commonly led to the death of the patient, not because of pain per se, but because the surgeon had no time in which to think and take deliberate action. So practical were the properties of anaesthetics, that their clinical use spread rapidly throughout the medical world without the least understanding of the mechanisms by which the agents worked. The drugs obviously produced unconsciousness and freedom from the perception of noxious stimuli. It was also desirable that they did so as rapidly as possible, and that such effects were completely reversible with few physiological side effects. We would not dispute these requirements today. Within the context of thencurrent chemical knowledge, three agents appeared to fit all or some of this description. Diethyl ether, as used by Morton, became the standard for generations. Nitrous oxide provided all the correct attributes but one sufficient potency to cause unconsciousness and surgical anaesthesia. Chloroform also provided the requisite analgesia and unconsciousness and was used for decades, despite its potentially lethal side effects. The early lack of understanding and, indeed, concern about anaesthetic mechanisms of action should not be too surprising. Very few of the drugs then in use were understood in any detail. Drugs were found largely by trial and error in animals and humans. That they worked and were relatively safe was all that was required. In the context of this pragmatic medical world, Ernest Overton was a fascinating exception. Bom in Cheshire, England, in 1865, Overton was a distant relative of Charles Darwin. His maternal grandfather, Reverend W. Darwin Fox was an entomologist, second cousin and close friend of Darwin. With his family, Overton moved to Switzerland at the age of seventeen and there completed his education. He received