From Craft to Profession: The Development of Modern Anesthesiology

In Missouri Medicine’s Part I of the History of Anesthesia,¹ it was noted that Dr. Crawford Long, a physician in Jefferson, Georgia, performed the first recorded ether anesthetic in 1842. He subsequently performed several other successful anesthetics prior to 1846, yet he did not announce his medical discovery until 1849. Separately, others were experimenting with ether and nitrous oxide as party enhancers, but not as anesthetics.

On September 25, 1846, a man named Edward Abbott presented to Massachusetts General Hospital for a medical evaluation. His chief complaint: a growth under his left jaw. By October 16, 1846, Dr. William Thomas Greene Morton, innovator, dentist, and anesthetist, had perfected his breathing apparatus, the Ether Dome, to demonstrate general anesthesia.² Abbot was reassured by Dr. Morton, and within four minutes, as Dr. Nathan Rice, a contemporary of Morton, describes in Trials of a Public Benefactor, Abbott soon “lay as quietly and soundly asleep as any child, in that curious state which is – ‘Twist gloom and gleam, with Death and Life at Each Extreme.’”³

Unfortunately, a photographer was not present at the 1846 unveiling of etherization. What is left, however, is a steel engraving printed in Dr. Rice’s summary of the day, which depicts the spectacle – Abbott, in the center, surrounded by eight colleagues as the procedure unfolds (Figure 1). The public display of the etherization of Edward Abbott at Massachusetts General Hospital opened the proverbial door to a whole world of new possibilities in surgical intervention. The demonstration set into motion the quest to advance general anesthesia practice.

Figure 1.

Edward Gilbert Abbott and his ether demonstration.

Source: https://www.nejm.org/doi/pdf/10.1056/NEJM198410113111522

However, the desire to understand, and thereby reduce, pain had long been part of medical discovery. In fact, Hippocrates was one of the first physicians to write about “anesthesia” and “analgesia” in his works. He observed that those who are “unconscious to everything” are “deaf to what is spoken, blind to what is happening and insensible to pain.”⁴ However, many centuries passed before this “unconsciousness” could be safely delivered and available for commercial, widespread use and was deemed a necessity for surgical intervention.⁵ Historians argue that the reasons for the delay in understanding and widely accepting the need for anesthesia in surgical practice are most likely a result of the scientific community’s disbelief in the ability to free oneself from pain. French surgeon Alfred Velpeau, in 1839, said, “The abolishment of pain in surgery is a chimera. It is absurd to go on seeking it...knife and pain are two words in surgery that must forever be associated in the consciousness of the patient.”⁵ The events that took place between the 1840s and present day, from advancements in medical technology to the development of the field of perioperative medicine, reflect the progression from the mysticism and disbelief in the existence of anesthetic to the firm understanding that reducing pain is not only possible but also entirely necessary. This shift is paralleled by advancements that have been centered in advancing patient safety, thereby cementing this value as a core tenet in the practice and field of anesthesiology.

Public Demonstrations of Anesthesia

Modern day anesthesia practice’s earliest, and most recognizable roots, were set into motion in the American 1840s. While the thought of public demonstration of medical discovery, especially when said discovery involves potential harm to a patient, seems unethical in present-day medical practice, public demonstration was central to the discovery of inhaled anesthetic. In 1844, Gardner Colton, a medical student at what is now Columbia University, displayed the intoxicating effect of nitrous oxide—for a fee. His advertisement in the Hartford Courant boasted that “Twelve Young Men have volunteered to inhale the Gas, to commence the entertainment.” For twenty-five cents a ticket, attendees could partake in both watching others and inhaling, themselves, nearly “forty gallons of gas.” They could observe their fellow participants’ “laugh, sing, dance, speak, or fight...according to the leading trait of their character” (Figure 2).⁶

Figure 2.

In Schenectady, New York, by mid-March of 1863, broadsides advertised a free “Exhibition of the LAUGHING GAS” scheduled for the afternoon of March 26, 1863. A traveling showman named “Doctor” Gardner Quincy Colton (1814–1898) promised to gas 12 women recreationaly with nitrous oxide, the same gas that he had provided as a dental anesthetic in 1844 for Horace Wells.

Source: https://www.woodlibrarymuseum.org/wp-content/uploads/reflections/011_Colton_N2O_Broadside_GS.pdf

Horace Wells, a dentist and audience member at such a demonstration, noticed that while intoxicated, a participant who had inhaled nitrous oxide did not feel pain from an injury he sustained. Wells subsequently sought Colton’s assistance in administering nitrous oxide to himself while one of his assistant’s removed his tooth. He was eventually able to administer nitrous oxide to several of his patients, the success of which prompted him to approach John Warren, famed surgeon at Massachusetts General Hospital, to stage a public demonstration at Harvard Medical School. However, the event was unsuccessful, with attendees and his peers criticizing Wells’ attempt as “humbug.”⁷ Dr. Morton, Wells’ student and fellow dentist, posited that ether could be used as a substitute for nitrous oxide. He tested ether on pets, himself, and a handful of patients prior to approaching Dr. Warren for his own chance at a public demonstration of etherization of Mr. Edward Abbott. Public demonstration offered with it the prospect of public entertainment and its associated financial gain.

Morton’s demonstration of etherization at Massachusetts General Hospital spurred the race to obtain patent rights for ether, and thereby commercialize its use. By contrast, Morton was soon embroiled in a battle with the U.S. government to deem his patent of ether, or “Letheon,” as he named it, to be enforceable. Unfortunately for Dr. Morton, the use of ether spread across the U.S. and even abroad, with many European, Australian, and Latin American practitioners employing its use, and he did not amass a fortune from its increased use. However, the demand did encourage the discovery of safer methods to administer ether and develop alternative forms of inhaled anesthetic gas.⁷

Understanding Depth of Anesthesia

A professor of obstetrics in Scotland, Dr. James Simpson introduced the use of chloroform in 1847. Although hepatotoxic, more potent, and consequently more lethal than ether, its use was more manageable in his patients. After inhaling chloroform himself, Simpson claimed the substance was “far stronger and better than ether.”⁸

Chloroform soon became the anesthetic of choice in the United Kingdom, mainland Europe, and much of South America. Chloroform was even famously used by Queen Victoria during the birth of her son, Prince Leopold, in 1853 (Figure 3).⁸ This “celebrity event” significantly increased awareness, and subsequent demand, for labor analgesia.

Figure 3.

From left to right, are a chloroform drop flask, a drop bottle with a control valve manufactured by Pilling & Son, and one of unusual, alembic form. Introduced just one year after ether, chloroform was the second drug to be used as a modern surgical anesthetic.

Source: Wood Library-Museum of Anesthesiology, Schaumburg, Illinois.

Anesthetist and renowned epidemiologist, John Snow, most famously regarded for the discovery of the spread of cholera at the Broad Street pump wrote some of the first observations in delivering these inhaled anesthetics that became the foundations for much of modern-day anesthetic practice. He described five “degrees” of anesthesia. This spectrum began with the first “degree” as when a patient “retains correct consciousness...and a capacity to direct his voluntary movements.” The fifth “degree” progressed to “respiratory movements [being] more or less paralysed and…difficult, feeble, or irregular.”¹⁰ This scale of sedation is reflected in the current American Society of Anesthesiology’s “Continuum of Depth of Sedation,” which classifies level of sedation from minimal anxiolysis to general anesthesia.²¹ Through his observations, Snow observed differences in type of anesthesia and patient outcomes, further advancing strategies for patient safety. He compared death rates between ether and chloroform use, stating that deaths from chloroform were “accidents [that] would arise by it suddenly paralyzing the heart, if it were not sufficiently diluted with air.” He thus embarked on the task of creating a delivery system for temperature-controlled, diluted ether, which is the most rudimentary version of the modern-day variable bypass vaporizer. His work also led to discoveries of minimum alveolar concentration and pharmacology of inhaled gases.⁹ The retrospective analysis of outcomes from two different anesthetic agents further laid groundwork for large strides in patient safety in anesthesia; much of the following century’s global anesthetic practice was based on Snow’s foundational observations.

Advances in Airway Control

Along with a more clear understanding of the scope of anesthesia came the development of devices that could be used for airway control. Prior to the late 1800s, few oral airway devices existed, and their primary use was for treating neonatal distress and pediatric asphyxiation, a common complication of diphtheria at the time. These devices were not widely available, however, for most surgical procedures. In the late 1800s, the need for airway control came from the growing demand for oral surgery; surgeons desired a method to prevent blood and surgical debris from entering the airway.¹¹ Many versions of the modern-day endotracheal tube were developed during this time, primarily fashioned out of metal and rubber.

Dr. Frederic Hewitt, in 1902, delivered a chloroform-ether mixture to future King Edward VII, who was known to have a large beard. In anticipation of the challenges of safely delivering inhaled gas with an interfering beard, Hewitt developed the oral “airway,” fashioned out of rubber and metal (Figure 4).¹² He described its intended use: “If at the conclusion of the induction period...the breathing be laboured and noisy with sniffing or snorting sounds...the jaws should be separated and the whistle-shaped end of the ‘air-way’ passed backwards.” He also noted that Trendelenburg positioning was more likely to cause airway obstruction. However, without full control of the airway, pulmonary complications with anesthesia remained common.¹²

From here, in 1928 Dr. Paluel Flagg, American anesthesiologist and fierce patient safety advocate, sought to better understand and prevent asphyxiation during surgical procedures. While commonly using variations of Hewitt’s oral airway to prevent obstruction during surgery, Flagg developed a two-piece metal endotracheal tube that had a rigid stylet that could be removed following insertion; a rubber stopper could be added on top to create an airtight seal. Dr. Flagg’s interest in developing better endotracheal tubes eventually led him to create the Society for the Prevention of Asphyxial Death, an organization that instructed physicians to understand and practice cardiopulmonary resuscitation.¹³ The emphasis on patient outcomes and safety during the early 1900s allowed for widespread practice of anesthesia during the World Wars.

Demand for Anesthesia Soars

Between World War I and II, due to battlefield trauma, there was a sudden increase in surgical procedures, and with it, the need for anesthesia increased as well. This change coupled with the advertisement of anesthesia as the “hit show” at the 1939 World Fair increased public awareness of the field.²⁴ With World War I came the establishment of the first nurse anesthesia schools and subsequently the first academic department of anesthesia at the University of Wisconsin. The Long Island Society of Anesthetists, founded in 1905 and the precursor to the present-day American Society of Anesthesiology, became a rapidly growing organization during this time period.²⁵ By World War II, with the growing need for anesthesia in wartime surgery, many physicians were drafted to provide anesthesia.¹⁴ With the sudden rise in the global death rate, as surgeon Erwin Schmidt wrote in the Annals of Surgery in 1937, “Anesthesia was gladly welcomed, but received little aid or stimulation...by the surgical profession.” He continues, “This attitude placed anesthesia in the hands of young assistants who looked upon it as a necessary evil.” Necessary evil or not, the largest growth in advancements in technology, pharmacology, and anesthetic practice standards took place in the World War era. With the growing possibilities of the anesthetic expertise that physicians could offer surgeons for their procedures, anesthesia soon became its own medical specialty.

Noting the growing opportunities for anesthesiology, war-time anesthesiologist Henry Ruth wrote, “After such an experience, it is to be seriously doubted whether many of [the surgeons] will be content on their return to civilian practice to retrogress to the inferior type of unsupervised technician anesthesia.”¹⁸ Between 1940 and 1950, the percent growth of the number of members in the American Society of Anesthesiologists was more than 230%.¹⁸

Advances in Patient Safety

With the development of better technology to deliver anesthetic gas, instruments to maintain airway patency, and new pharmacotherapies that could facilitate anesthesia, the focus of anesthetic practice soon centered on improving patient safety. This growth was reflected in the new instruments and medications that physician-anesthetists, as they were referred to at the time, could use.¹⁸

War-time anesthesiologist and one of the first anesthesiologists to study patient outcomes, Henry Beecher, cataloged the number of “anesthesias,” or delivered anesthetics, in a multi-institution analysis as 7,650 in 1943 and 19,914 in 1944. In that one year interval, the overall anesthesia-related death rate fell from 1:1,000 to 1:5,000.¹⁹ Simultaneously, discovery in pre-operative preparation, antibacterial technique, and new surgical technique made the realm of possibilities even wider.

In 1937, Professor Robert Macintosh, appointed as chair of anesthesia at Oxford, developed the curved laryngoscope blade. In 1948, Dr. Lucien Morris designed the copper kettle vaporizer, which could better regulate the temperature of liquid and thereby better control the speed and delivery of anesthetic vaporized gas.¹⁶ Advances in pharmacology, too, meant that new intravenous induction agents, such as sodium pentothal, were available. As Beecher writes, the use of sodium pentothal is “admirably suited to the needs of warfare.”¹⁹ Beecher conducted an analysis on the death rate associated with pentothal and reported a decrease in the death rate from 1:450 to 1:5,500 between 1943 and 1944.

Anesthesiology was progressing to become a safer, more predictable field. Additionally, curare, a muscle relaxant derived from plants native to Ecuador and Peru, where it was commonly used as an agent that could coat arrows and darts to facilitate hunting, was brought into anesthetic practice in 1942.¹⁷ By 1944, lidocaine was introduced in Sweden as a local anesthetic. With these advancements and the advent of controlled ventilation, longer surgical procedures, and even one-lung ventilation were possible.

The early development of anesthesia focused on strategies to address pain; with rapid advancements in anesthesia during World War II, considerations about post-operative outcomes, infection control, and patient satisfaction expanded anesthesiology’s scope to include what is now known as “perioperative medicine.”

Specialization in anesthesia first started in the post-World War II era. Pediatric anesthesia became a subspecialty, along with obstetric anesthesia and the use of spinal anesthetic. Dr. Virginia Apgar, best known as the creator of the “Apgar Score” to assess the health of a newborn child, became a pioneer in obstetric anesthesia and neonatology during this time.¹⁴

Regional anesthesia was also established as a tool for orthopedic and peripherally localized surgical intervention, with 19.8–38.2% of anesthetics in 1944 being spinal anesthesia and 9–19.7% being local.¹⁹

In tandem with regional anesthesia, pain medicine also saw major strides in medications and interventions; Beecher’s works analyzed effective use of morphine in analgesia of surgical patients, for instance. The concurrent development of new antibiotic medications, antiseptic technique, and pre-operative preparation meant that anesthesiologists had many elements of surgical care to manage beyond simply the delivery of a safe anesthetic.

The development of the first blood bank in the U.S. in 1935 helped advance patient safety during surgery. Patients could now be medically optimized prior to surgical intervention through a variety of measures, which significantly reduced the anesthesia-related death rate at the end of the 20th century.¹⁴

With the growing concern for patient safety and post-anesthesia outcomes, anesthesia soon emerged in the late 20th century as a field centered on facilitating monitored, medically optimized, and ethical care. Following his appointment to the first department chair of anesthesiology at Harvard, Beecher advocated for the importance of bringing ethics into anesthesia practice. He wrote that in order for the field of anesthesia to make advancements through research, human experimentation needed to be conducted safely and ethically. “First, there is the problem of consent, seemingly so simple and straightforward, but often far from simple; second, there is the problem of the ethical justification for experimentation on one subject which cannot in any way be construed as for his benefit but is for patients in general.”¹⁵ This discussion led to the formal process of informed consent prior to administering anesthesia.¹⁴

Creation of Safety Standards

Established standards for safety were also a key addition to the field. Beginning in the 1970s, the number of medical malpractice lawsuits started to increase, and anesthesia-related complications were more commonplace than they are today. For instance, it was not uncommon for an anesthesiologist to leave an intubated and sedated patient’s bedside to procure medications or take a break. The adverse events that ensued were reflected in the rise in malpractice lawsuits; in the 1980s, anesthesiologists at all Harvard hospitals accounted for 3% of the physician staff but a staggering 12% of all medical malpractice cases.²⁰ ASA President Dr. Ellison Pierce grew increasingly concerned at this statistic and started the ASA Standards Committee.

What was revolutionary about these “standards” were that they were not recommendations or suggestions, but enforceable measures that, if not followed, could result in an anesthesiologist’s culpability in these malpractice cases. The result is that anesthesiologists were forced to follow a set of standards that were validated through retrospective analysis, and anesthesia became one of the first fields to enforce universal safety standards.²⁰ The creation of the Anesthesia Patient Safety Foundation (APSF)in 1985 was the next large step in improving patient outcomes. Following this growing concern that anesthesia care itself was the cause of patient mortality, a focus that was further emphasized by national media coverage of several adverse events from anesthesia, the APSF was created with the goal that “no patient shall be harmed by anesthesia.”²⁶ This goal was reflected in improved patient outcomes with anesthesia; by the 1990s, the mortality rate fell to 1 in 200,000 anesthetics delivered.²⁷ In an effort to reduce medical malpractice, the ASA Closed Claims Project subsequently began, with the goal of creating a database of all closed malpractice claims for analysis. The result was that anesthesia-related complications could be quantified and categorized, which ultimately facilitated injury prevention standards that are now routine.²¹

The gradual reduction in adverse patient outcomes and severity of malpractice cases reflects what has ultimately always been at the heart of anesthetic practice: patient safety. While the history of medicine has a pattern of groundbreaking discovery often at the expense of cultural prejudice, exploitation of persons without consent, and lack of formal scientific analysis, the history of anesthesia from the 1840s to present day marks a cultural shift away from these themes. The progression of anesthesiology from a craft that could be capitalized for entertainment to a trade that many did not want to take on to, ultimately, a profession with a wide breadth of practice is relatively recent. The inspiring and creative physicians and scientists that paved the way for modern-day anesthesia understood that established practices can and must always be adapted for the best interest of the patient. To understand the history of anesthesia, it would serve the field well to remember that progress, whether in technology, pharmacology, or patient outcomes, is only possible by continuing to strive for improvement, a practice that has long been set as a precedent.