#241 Why does chloroform knock people out?

I learned this today. Chloroform knocks people out by causing depression of the central nervous system.

Chloroform appears to have been discovered by several people independently in 1830 and 31. A German pharmacist called Moldenhawer discovered it in 1830. An American physician called Samuel Guthrie, a French scientist called Eugene Soubeiran, and a German scientist called Justus von Liebig all appear to have discovered it independently in 1830.

The discovery was named “chloroform” in 1834 by Jean-Baptiste Dumas. The name comes from chlorine and formic acid, two of the main ingredients in it.

However, these scientists didn’t realize the anesthetic properties of chloroform. The American Guthrie was trying to make a cheap pesticide. He mixed chlorinated lime with ethanol.

The discovery that it could be used as an anesthetic was made by an English physician called Robert Mortimer Glover. He discussed it in a thesis and performed tests on dogs to prove it. He also presented his ideas in the thesis for his doctorate in 1847. A Scottish physician called Sir James Young Simpson read this thesis. However, Simpson later claimed that he had never read the thesis and had discovered the effects of chloroform on his own. He said that he discovered its properties at a dinner party. Ether was already used as an anesthetic and Simpson said that he was on the search for a better one. At a dinner party, he and his friends experimented by sniffing various chemicals until one of them came upon chloroform. That must have been a fun dinner party.

Simpson introduced chloroform as an anesthetic on November 8, 1847. He used it to relieve the pain of childbirth and a lot of people attacked him on moral grounds. They thought the pain was an important part of childbirth and that not experiencing the pain would damage the bond between mother and child. I’m guessing that most of the people who complained were men. These attacks continued until Dr. John Snow gave chloroform to Queen Victoria for the birth of her eighth child. This gave it the seal of approval and it became common.

Simpson was knighted in 1866 and the media heavily covered the use of chloroform as the new anesthetic. Simpson became known as its discoverer.

So, why can chloroform be used as an anesthetic? What does it do to the body? It turns out that nobody seems to know. There are theories as to why anesthetics make people unconscious, but nobody has the exact answer.

One theory is that the chloroform increases the movement of potassium ions through potassium channels in nerve cells. This affects the body’s response to nerves because the neuron is frozen and cannot fire. A second theory is that the chloroform interferes with cell membranes and slows down the passage of nerves. A third theory is that the chloroform activates the neurons that make us fall asleep. When anesthetics are given to mice, neurons in their brains fire and release large amounts of hormones such as vasopressin into the blood stream. This is possibly a pain relief hormone. Anyway, the answer seems to be that there isn’t one answer yet.

One thing does seem to be known, and that is that chloroform is not very good for you. Chloroform became a very popular anesthetic in the late nineteenth century and up to about 1930. By then, research into the dangers of chloroform had been carried out and it was slowly banned in different countries.

It was extremely difficult to give a correct dose of chloroform. If too much was given it could paralyze the longs. It also caused cardiac arrhythmias. This is an irregular heartbeat. Basically, because the drug was messing with the nervous system, it was causing organs that relied on the nervous system to shut down. The research showed that the chances of dying while using ether as an anesthetic were between 1:14,000 and 1:28,000, while the dangers from using chloroform were between 1:3,000 and 1:6,000.

It could be said that using modern day monitoring methods, the risk of fatality under chloroform could be lower than they were a century ago, but other, better drugs have been found in the meantime.

There is also the myth that people can be knocked out in seconds using chloroform and carted away. That is not true because it takes about five minutes for the effects of chloroform to be felt and even then, it must be breathed constantly for the patient to stay under.

So, chloroform knocks people out by affecting the nervous system in some way, although nobody knows exactly how. And this is what I learned today.

Photo By Kevin King – Flickr: Chickamauga 2009, Chloroform, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=12429674

Sources:

https://dhss.delaware.gov/dph/files/chloroformfaq.pdf

https://en.wikipedia.org/wiki/Chloroform

https://en.wikipedia.org/wiki/James_Young_Simpson

https://en.wikipedia.org/wiki/Allosteric_modulator

https://pubs.asahq.org/anesthesiology/article/92/1/290/37485/Was-Chloroform-Produced-before-1831

https://www.thehistorypress.co.uk/articles/chloroform-170-years-of-controversy/

https://simple.wikipedia.org/wiki/Chloroform

https://www.history.com/topics/inventions/ether-and-chloroform

https://www.soap.org/sir-james-young-simpson