60 Fun Facts About Anesthesia

What are the three broad categories of anesthesia?

General, sedation and regional or local differ in how much of you is switched off. Under regional anesthesia a woman can stay awake through childbirth, while sedation can run from drowsy but talking to deep.

What are the three basic goals or endpoints of anesthesia?

Hypnosis, analgesia and muscle relaxation are produced by drugs acting on different parts of the nervous system, which is why an anesthetist usually combines several agents instead of relying on one.

Roughly what proportion of patients become aware during surgery under general anesthesia?

1 or 2 in 1,000 is the usual estimate, and most of those patients feel no pain. It is likeliest in emergencies such as urgent caesareans and trauma surgery, where a full dose of anesthetic would be unsafe.

About one patient in five reports having done what under general anesthesia?

Dreamed, said 22% of patients in one careful study, and the dreams were mostly pleasant and nothing to do with surgery. They were no sign of too light a dose: they seem to come as the drugs wear off.

The potency of an inhaled anesthetic correlates with its solubility in what?

Oil: around 1900 Meyer and Overton found that the more readily an anesthetic dissolves in olive oil, the more potent it is. For decades that pointed to nerve cells' fatty membranes; the main targets are now thought to be proteins.

A general anesthetic usually begins with a fast-acting injection that puts the patient under; what is this stage called?

Induction. A drug injected into a vein, an approach dating from the 1930s, puts a patient under within about a minute; gas through a mask is now the fallback when a vein is hard to find.

The pulse oximeter clipped to a finger during anesthesia reads the blood's oxygen level using what?

Beams of light. Oxygen-rich and oxygen-poor blood absorb red and infrared light differently, a trick Japanese engineer Takuo Aoyagi turned into a bedside monitor in the 1970s.

What is sedation with benzodiazepines commonly nicknamed?

Twilight anesthesia. The patient stays drowsy but can answer the team and breathe unaided, yet often remembers little afterwards; painkillers are added because the sedatives don't dull pain.

An epidural stops outside the spine's protective membranes; a spinal anesthetic is injected through them into what?

The cerebrospinal fluid. A spinal is a single shot into the fluid of the subarachnoid space and works almost at once; an epidural's thin tube stays in place so the dose can be topped up.

Why does blood pressure commonly drop after a spinal or epidural block?

It causes arterial and venous vasodilation. The drug also numbs the nerves that keep blood vessels tight, so the vessels relax and less blood flows back to the heart.

Anesthetists give every surgical patient an ASA grade from 1 to 6; what does it rate?

Their overall health. Grade 1 is a fit, healthy person and grade 6 a brain-dead organ donor; the scale dates from 1941, when anesthetists wanted one shared yardstick for comparing their results.

What do anesthetists call the final phase of a general anesthetic, when the patient wakes?

Emergence. Waking is more than the drugs wearing off: a 2014 study of anesthetised rodents found the brain steps through a set of activity 'hubs' in order before consciousness returns.

Postoperative cognitive dysfunction, a mental fog that can linger for months after major surgery, mainly threatens which patients?

Adults over 60. Its cause is still unclear: the body's inflammatory response to the operation is a leading suspect, and the anesthetic itself may not be to blame.

Which ancient people are said to have cultivated the opium poppy as early as 3400 BCE?

The Sumerians. They are said to have called the poppy hul gil, the 'joy plant', and to have passed it on to the Assyrians, though some scholars doubt the term meant opium at all.

The 2nd-century Chinese surgeon Hua Tuo reportedly knocked patients out by dissolving his herbal powder mafeisan in what?

Wine. The recipe died with him: the warlord Cao Cao had Hua Tuo executed, his writings were burned, and the formula has been lost ever since.

What are Inca shamans said to have chewed and spat into skull wounds to numb them?

Coca leaves. No record confirms the practice, only later suggestion, but the surgery itself was real and skilled: about four in five Inca-era patients survived having their skulls opened.

What was the medieval soporific sponge soaked in?

Opium, mandragora and hemlock juice. The sponge was dried, then wetted again just before surgery and held to the patient's nose until sleep came.

Which 16th-century physician noted that chickens dosed with ether fell into a long sleep and woke unharmed?

Paracelsus. He wrote that his 'sweet vitriol' quieted suffering and relieved pain, yet never tried it on patients; the jump from chicken to operating table took another 300 years.

Who discovered nitrous oxide in 1772?

Joseph Priestley. He made the gas by heating iron filings dampened with nitric acid but never tried breathing it himself, so its strange effects went unnoticed for a quarter of a century.

Which chemist experimented on himself with nitrous oxide in 1799 and gave the gas its famous nickname?

Humphry Davy. Breathing the gas dulled the ache of a wisdom tooth, and he wrote that it might be used in surgery, a hint nobody followed up for more than 40 years.

Why did Hanaoka Seishu's 1804 general anesthetic stay unknown in the West for decades?

Japan was closed to foreigners until the 1850s, by which time the West had ether. Hanaoka had spent some 20 years perfecting his herbal brew, and his wife, who volunteered to test it, lost her sight.

The first documented patient under general anesthesia, a 60-year-old Japanese woman in 1804, had which disease?

Breast cancer. Kan Aiya slept through the removal of her tumour and went home, and her surgeon went on to perform more than 150 such operations before his death in 1835.

Which Georgia doctor removed a tumor under ether on 30 March 1842 but did not publish until 1849?

Crawford Long. He held back because he wanted to repeat the result until he was sure, and so lost the credit in his lifetime; National Doctors' Day now falls on 30 March, the date of his operation.

Which dentist's 1845 demonstration of nitrous oxide in Boston failed when the patient cried out?

Horace Wells. A day after watching a showman's volunteer injure his leg without noticing, Wells had his own wisdom tooth pulled painlessly; the Boston failure brought ridicule that hurt him deeply.

Who gave the first successful public demonstration of ether anesthesia on 16 October 1846?

William T. G. Morton. He nearly missed it, arriving late because he was still adjusting his inhaler; he later asked Congress for a $100,000 reward, but rival claimants blocked it.

What did surgeon John Collins Warren reportedly say after the 1846 public demonstration of ether?

Gentlemen, this is no humbug. No eyewitness report from 1846 records the line; it first appeared in an 1859 biography, three years after Warren's death, and historians doubt he ever said it.

Under what invented name was ether patented in 1846 to disguise what it really was?

Letheon. The name borrowed the Greek word for forgetfulness, as in the mythical river Lethe, but the vapour was soon recognised as plain ether, and surgeons used it freely whatever the patent said.

Why are patients told not to eat for hours before a general anesthetic?

Stomach contents can enter the lungs. Anesthesia switches off the gag and cough reflexes that guard the airway; the lung injury that can follow is named after Curtis Mendelson, who described it in 1946 in women anesthetised in labour.

Who proposed the words anesthesia and anesthetic in an 1846 letter?

Oliver Wendell Holmes. 'Everybody wants to have a hand in a great discovery,' the Boston physician and poet wrote, offering only a name; his son and namesake became a Supreme Court justice.

Which Scottish obstetrician first demonstrated the anesthetic properties of chloroform on humans in 1847?

James Young Simpson. He and two assistants inhaled it one evening in the dining room of his Edinburgh home and all passed out; within weeks he had published his account.

Which monarch received chloroform from John Snow in childbirth in 1853?

Queen Victoria. She called the chloroform 'soothing, quieting and delightful beyond measure' at Prince Leopold's birth, and her example helped make pain relief in labour respectable.

John Snow, a pioneer of anesthesia, traced an 1854 cholera outbreak in London's Soho to what?

The Broad Street water pump. Snow mapped the deaths clustered around it and had the handle taken off; brewery workers and workhouse inmates nearby, who drew their water elsewhere, were spared.

A 2004 study found that women with which natural hair colour needed about a fifth more anesthetic gas?

Red. The study covered just 20 women, though; two later studies of hundreds of surgical patients found that redheads needed no more anesthetic than anyone else.

Alice Magaw, the nurse known as the 'Mother of Anesthesia', worked for which famous American brothers?

The Mayo brothers. Magaw refined the art of dripping ether onto a gauze mask at their Minnesota hospital, and her 1906 review covered more than 14,000 anesthetics without one death from the anesthetic.

Which was the first effective local anesthetic?

Cocaine. In 1884 the Viennese eye doctor Karl Koller showed it could numb the eye for surgery, and the '-caine' ending of later numbing drugs was borrowed from its name.

Whose 1884 paper noted a drug's numbing power in passing, leaving a colleague to discover local anesthesia?

Sigmund Freud. His paper praised the drug as a remedy for many ills; his Vienna colleague Karl Koller tried it on the eye months later and took the credit.

The 'novocaine' patients expect at the dentist today is usually which newer drug, first made in Sweden in 1943?

Lidocaine. Swedish chemists Nils Löfgren and Bengt Lundqvist made it in 1943, and it proved such an advance on procaine, the real Novocain, that it has been the dentist's standard ever since.

Which arrow poison became a surgical muscle relaxant after a Montreal team used it in a 1942 appendectomy?

Curare. It only paralyses muscle, leaving pain and awareness untouched, so Harold Griffith's team gave it on top of an ordinary anesthetic, and it transformed operating conditions for surgeons.

Which milky-white IV anesthetic, first sold as Diprivan, is an emulsion of soybean oil and lecithin?

Propofol. Making it injectable took years and nearly sank the project; developer John Glen kept it alive, and patients wake from it so fast and clear-headed that it became the most used drug for starting anesthesia.

Which musician's 2009 death from an anesthetic plus benzodiazepines drew attention to the drug's off-label use?

Michael Jackson. His doctor, Conrad Murray, had been giving him the surgical anesthetic at home as a nightly sleep aid, and was convicted of involuntary manslaughter in 2011.

Which anesthetic induces a dissociative trance while preserving breathing and airway reflexes?

Ketamine. Patients can look awake yet register nothing around them; because breathing carries on unaided, the drug is a mainstay of emergency and trauma care.

Before anesthesia, London surgeon Robert Liston was celebrated above all for which quality at the operating table?

Speed. With patients awake and strapped down, he is said to have taken off a leg in two and a half minutes; in December 1846 he tried ether for an amputation and declared that the 'Yankee dodge' beat mesmerism hollow.

Why do dentists' local anesthetic injections often contain a small dose of adrenaline?

To make the numbness last longer. Adrenaline narrows the blood vessels around the injection, so the drug is carried away more slowly and the gum bleeds less while the dentist works.

Which drug is the specific treatment for malignant hyperthermia, a rare reaction to volatile anesthetics?

Dantrolene. It blocks the runaway release of calcium inside muscle cells that makes them burn energy and overheat; a reaction that once killed most patients now kills about one in twenty.

Which famous 19th-century anesthetic remained in wide clinical use into the 21st century?

Laughing gas. Nitrous oxide is still breathed in dental chairs and delivery rooms, while chloroform's habit of upsetting the heart's rhythm drove it from the operating room.

Which US president had a tumour secretly cut from his jaw under ether aboard a friend's yacht in 1893?

Grover Cleveland. Fearing the news would deepen a financial panic, he vanished for four days; surgeons worked through his mouth so no scar would show, and a reporter's account was denied until a surgeon confirmed it 24 years later.

What kept August Bier in bed for days after trying spinal anesthesia in 1898?

Headache. He had let his assistant try the needle on him; Bier traced the pain to the puncture it leaves behind, and today's much finer needles make such headaches far less likely.

What did the FDA warn in 2016 about repeated or lengthy anesthesia in children under three?

It may affect brain development. The warning rested largely on animal studies; a later international trial found that about an hour of anesthesia in infancy made no difference to children's development at age five.

The word 'anesthesia' was built from Greek roots that literally mean what?

No sensation. It joins an-, 'without', to aisthesis, 'feeling', the root that also gave us 'aesthetic'; the word sat in medical dictionaries for over a century before surgeons had the means to earn it.

A dentist who numbs one whole side of the lower jaw at once is using which technique?

A nerve block. The drug is placed beside the nerve trunk before it enters the jawbone, so every tooth it supplies goes numb at once; infiltration, by contrast, soaks through the bone around a single tooth.

Which naturalist abandoned his medical studies in the 1820s after fleeing operations performed without anesthesia?

Charles Darwin. At Edinburgh he rushed out of two operations, one on a child, and never went back, writing later that this was 'long before the blessed days of chloroform'.

Which injected drug, first given in 1934, became the standard way to put surgical patients to sleep for decades?

Sodium Pentothal. Chemists at Abbott made the drug, properly called thiopental, and it worked in well under a minute; popular culture later made it famous as a 'truth serum', a power experts doubt it has.

Where did anesthetist Arthur Guedel put his sleeping dog to show his cuffed breathing tube worked?

Water tank. The inflated cuff sealed the windpipe, so the anesthetised dog could be kept breathing through the tube while fully submerged, and it came out unharmed.

What does an anesthetist use a Macintosh blade for?

Inserting a breathing tube. Designed in 1943 and still the most widely used of its kind, the blade never cuts: its curved tip lifts the epiglottis clear to show the vocal cords.

Which Belgian pharmacologist's team synthesised fentanyl around 1960?

Paul Janssen. Fentanyl turned out roughly 100 times as potent as morphine and became one of the world's most widely used opioids, first in operating rooms and later, disastrously, on the street.

Halothane, introduced in 1956, had what major safety advantage over ether and cyclopropane?

It was not flammable. Ether and cyclopropane vapour could catch fire or explode in the operating room; halothane ended that risk, until rare cases of severe liver damage saw newer agents take its place.

Which effect did Harvard anesthetist Henry K. Beecher bring to wide attention with a famous 1955 paper?

The placebo effect. His paper claimed that about a third of patients improved on dummy treatment, and medicine took the effect as fact; a 1997 re-analysis found no real placebo effect in his data.

In Copenhagen's 1952 polio epidemic, what did hundreds of medical students do around the clock to keep paralysed patients alive?

Squeeze air bags by hand. Anesthetist Bjørn Ibsen had the air pushed in through a tube in the windpipe; deaths fell from nearly nine in ten to well under half, and the wards set up for the patients grew into intensive care.

Which non-greenhouse noble gas won approval as an anesthetic in Europe in the 2000s?

Xenon was approved in Germany in 2005 and more widely in Europe in 2007. The 21st century also brought video laryngoscopes such as the Glidescope, which use digital sensors to view the glottis.

Veronal, a sleeping pill Bayer sold from the early 1900s, was the first of which drug family?

Barbiturates. They were the mainstay sleeping pills and sedatives until about 1960, when benzodiazepines, far less deadly in overdose, began to replace them; a few survive in anesthesia and epilepsy.