Surgical anesthesia in the Civil War and the present day – whither ether?

 - Harrison Smith-Jaoudi

The adoption of anesthesia as an integral part of major surgery in the Civil War owes much to publication efforts that provided military physicians, many with scant prior training or experience, practical guidance in the form of handbooks and manuals, the most widely distributed of which explained and advised surgical applications of inhalational anesthesia (https://pmc.ncbi.nlm.nih.gov/articles/PMC11191930/). The landmark Medical and Surgical History of the War of the Rebellion (MSHWR) records more than 80,000 instances of inhalational anesthesia, a “conservative figure” for the Union forces that includes 8,900 instances of use in “major operations” (https://pubmed.ncbi.nlm.nih.gov/20503754/). More than 160 years after the end of the war in 1865, it is of interest to see how essential aspects of the then-burgeoning practice of anesthesia appear in the present day. This post looks at one such aspect, the anesthetic agent ether, with an emphasis on merits recognized by Civil War physicians that contribute to its utility in present-day anesthesia.

The earliest attempts to free patients from surgical pain are presumably lost to the historical record, but nerve compression, to take one example, seems to be attested at least from the third millennium BCE in ancient Egypt. From then on, there are anesthetic efforts, some similarly rooted in now-recognizable aspects of human physiology, scattered across time and space, including forms of “refrigeration anesthesia” via the application of ice or snow, as performed by Marco Severino in the 1600s, through various applications of opiates and ethanol, with commensurately various levels of plausibility and success, into the 19th century. Perhaps most intriguing is the soporific sponge, a device applied beneath the surgical patient’s nose from the 9th through 13th centuries. By boiling mandrake leaves, poppies, nightshade, and other herbal components, practitioners managed to infuse the soporific sponge with scopolamine and morphine, two agents that still see anesthetic and perianesthetic application as, respectively, antiemetic and analgesic (https://oce.ovid.com/book?SerialCode=02274621).

Ether, a volatile liquid whose vapors serve as an inhalational anesthetic, may have been known, and some of its potential anesthetic properties recognized, from as early as the 8th century, by the author or authors of the Jabirian corpus in the Islamic Golden Age. In Europe it was perhaps known to Raymond Lully in the 13th century and certainly known, as oleum vitrioli dulce, to Paracelsus and Valerius Cordus in the 16th. Its entrance into the medical limelight as an anesthetic, however, had to wait until the mid-19th century. Following then-unpublicized applications by William Clarke and Crawford Long in 1842, dentist William Morton executed the first public demonstration of ether for surgical anesthesia at the Massachusetts General Hospital, on 16 October, 1846, roughly 15 years before the Civil War began. Experimentation with ether for surgical anesthesia, along with greater interest in nitrous oxide and soon chloroform as alternative inhaled anesthetics, had spread worldwide by the end of the decade (https://oce.ovid.com/book?SerialCode=02274621).

In the Civil War itself, ether did not enjoy universal application, despite the broad uptake of anesthesia in surgical practice. Instead chloroform, the other dominant anesthetic agent of the 1860s, was the sole agent in 76.2% of cases the MSHWR records; by contrast, ether was the sole agent in 14.7% of cases. The two jointly applied in the remainder of cases, an intriguing early demonstration of medical interest in the power of anesthetic agents to complement or compensate one another’s strengths and deficiencies (https://doi.org/10.1177/0310057X0603401S01).

Chloroform’s primary merits were rapidity of induction and emergence, low volume requirements and hence ease of transportability and application in the field, lack of both objectionable odor and superficial respiratory irritation, and, perhaps crucially, lack of flammability – all by contrast with ether. Chloroform, however, posed serious respiratory and cardiac risks in the short term, risks whose principled scientific investigation and impact in ending chloroform anesthesia extended well into the 20th century, but which were clearly known by the time of the Civil War. The difference in perceived safety between the two agents is nicely illustrated by the section on anesthesia in Stephen Smith’s (Union) Hand-Book of Surgical Operations, preserved online (https://archive.org/details/handbooksurgica00smitgoog/page/n41/mode/2up?view=theater), where the instruction that ether should be applied “lavishly” contrasts with the admonishment that “great care must be exercised” in the administration of chloroform. Comments from physicians of the time who compared the two agents show informative parallels to the current day. Surgeon B.B. Breed, for example, wrote that despite chloroform’s widespread and largely successful use, he “employed ether in preference… preferring, both from personal experience and observation the delay and discomfort in its administration to the possible danger from the use of the latter” (https://pubmed.ncbi.nlm.nih.gov/20503754/).

What Breed indicates here, aside from the inductive sluggishness and subjective noxiousness of ether, is its remarkable safety profile, a major contributor to its continued worldwide use. In resource- and training-limited circumstances, in particular, ether is still invaluable, for reasons that largely held in the Civil War era too. For one of many modern enumerations of these reasons, readers can turn to Improvised Medicine: Providing Care in Extreme Environments (2nd ed., 2016); a selection follows. First, both diethyl ether (most common in the Civil War and still commonly used) and divinyl ether (most preferable today) are easy to produce, and in exigency can be repurposed from industrial to medical application. Second, it offers a (comparatively) vast safety margin, i.e., the dose required for satisfactory surgical anesthesia and the dose at which adverse events become likely are so far apart that it has been called “fool proof”, even in inexperienced hands. It supplies “intrinsic analgesia [and] neuromuscular relaxation, is a bronchodilator, rarely potentiates the dysrhythmic effect of sympathomimetic agents, causes little uterine relaxation, stimulates blood flow (helpful in shocky patients), and stimulates respiration” (https://accessmedicine.mhmedical.com/content.aspx?bookid=1728&sectionid=115695659).

Of course there are myriad risks and caveats to be added. Certainly ether is no panacea, and the notion that any agent or procedure in medicine could be fool proof must be taken as hyperbolic. Still, ether is worth the attention not only of anesthesiologists and anesthetists, but of all practitioners with an interest in maintaining some of the advantages of surgical anesthesia when resources and training are limited. A celebration of ether anesthesia seems to be in order – just keep the matches and fireworks in another room.