THE FIRST ANESTHESIOLOGISTS found that they could harness the very power of sleep. With nitrous oxide, ether, or chloroform, they discovered a passageway leading to an insensible sleep known as narcosis. Their successors managed to explore that shadowy route, charting each individual patient’s course through it, and over the past 150 years anesthesiology can be said to have been fully realized as an instrument of medicine, to have been mastered.
Without ever having been understood.
Anesthesia has two basic extremes, and they just so happen to coincide exactly with the two most common fears regarding surgery: an application too strong, leading to death, and one too weak, leading to premature consciousness—the patient’s waking up in the middle of an operation. In the ongoing effort to avoid either case, the nineteenth century advanced on two fronts. The first improved the delivery system for anesthetic gases. The handkerchief soaked with chloroform was replaced by cone inhalers for ether after 1850 and by pressurized containers for nitrous oxide (with oxygen added) after 1868. By these means, especially the latter, the level of narcosis could be stably maintained through a series of weaker doses, “interval narcosis,” rather than one strong snort at the beginning. The second improvement was made in the close observation of the anesthetized patient’s vital signs. Long considered an advantageous luxury, this became widely practical in the latter part of the nineteenth century, when the administration of anesthetics moved away from the surgeon or his assistant to become an accepted specialty for both doctors and nurses.
Taut control over delivery systems and increased expertise in monitoring brought the most common anesthetics a long way toward safe application in the early years of this century. Even so, none of them was entirely acceptable: Ether was highly explosive, and chloroform had certain toxic properties, while the complaint against nitrous oxide, heard ever since 1846, was that it wasn’t quite strong enough. In 1929 a concerted effort sponsored by the British government (which had been dissatisfied by the performance of available anesthetics during World War I) resulted in the emergence of cyclopropane as the first “modern” anesthetic. Others followed; halothane, introduced in 1956, became the most prominent of all. Many operations today begin with the patient inhaling nitrous oxide as a preliminary anesthetic, to be followed by one or more other, stronger substances, such as halothane.
For all its long history, anesthesiology has seen great refinements in just the past generation. According to an article last year in the Journal of the American Medical Association , the death rate from anesthesia has dropped from one in 4,500 in 1970 to one in 400,000 today. Fear of anesthetic death, that lower extreme in the range of narcosis, has been rendered unjustifiable, at least from the statistical point of view. The other great fear, that of waking up prematurely, is still pertinent, however. About one percent of patients claim to recall becoming conscious during surgery.
—J.M.F.
