How Does Anesthesia Actually Put You to Sleep?
Knocked out, going under, sedated, put to sleep...there are plenty of
creative terms used to describe the experience of being under anesthesia,
but how does anesthesia actually put you to sleep? The crazy thing is, we don't actually
know for sure… but as you'll see in this video, sometimes it can go horribly wrong….
Anesthesia is one of the most commonly performed medical procedures out
there - more than 60,000 people undergo anesthesia every single day in the U.S.
alone. Despite its prevalence we still don't fully understand
exactly how anesthesia works in the human body to put us to sleep - we just know that it works.
The word anesthesia means ‘loss of sensation',
and millions of Americans undergo anesthesia every year to prevent them from feeling pain
and to keep them still and unresponsive so that doctors can safely perform life saving operations
that would be incredibly difficult - not to mention painful - to do to a conscious patient.
We may not fully understand how anesthesia works, but that doesn't mean it isn't a real life
medical miracle. Before the late 1800s, the only “drugs” we had to help patients through
painful procedures were things like alcohol, opium and hemlock - hardly fool-proof methods.
For centuries, medical procedures like tooth extractions and fracture repairs were performed
with very little - if any - pain relief for the patient. But, beginning in the 1840s, scientists
discovered that some gases, like sulphuric ether and chloroform, had sedative effects. Anesthesia
was born, and medical treatment became wildly less painful and traumatic than ever before in history.
Modern anesthesia cocktails are much safer and more reliable than these first gases were,
but we're still at a loss to explain exactly how they work to put us to sleep.
There are 4 categories of anesthesia - local, regional, sedation and general anesthesia. Local
anesthesia involves injecting a small amount of the drug into a specific area. This is the type of
anesthesia you'd get at the doctor's office before a filling or at the hospital before they stitch
you up. It's also used after major surgeries to help with pain as other, strong anesthesia begins
to wear off. Local anesthetic numbs only the targeted area, and wears off relatively quickly.
Similar to local anesthesia, regional anesthesia targets a specific area of the body,
though it is stronger than local anesthesia and can block sensation to an entire section of the
body. Epidural injections to the spine that are used to numb the lower body during labor,
and femoral nerve blocks that are injected into the femoral artery in the upper thigh
to freeze the entire leg for orthopedic surgery are just a few examples of regional anesthesia.
Both local and regional anesthesia leave the patient fully conscious - they don't “put you
under”. We need stronger stuff for that. Regional anesthesia is often combined with sedation. These
“twilight sedation” drugs make the patient more relaxed and unfocused. They don't force
the patient into unconsciousness, but many people do fall asleep under sedation due to the drowsy,
sleepy feeling it induces. Sedation doesn't affect breathing or reflexes,
making it less risky than full general anesthesia, and it also wears off more quickly.
When you picture a patient lying unconscious on the operating table waiting to be cut open,
what you're picturing is someone under general anesthesia. General anesthetic affects the entire
body and works in 4 ways. It immobilizes the body to stop it from moving during the procedure
and acts as an analgesic to prevent the patient from feeling any pain.
It also works on the brain by sedating the patient in an unconscious state,
and even induces amnesia to ensure the patient will have no memory of the experience.
In reality, “put to sleep” is not the best way to describe what it's like to be under general
anesthesia - it's actually more like being in a drug-induced coma. "It's a reversible coma,
but it's nevertheless a coma," says Emery Brown, a professor of anesthesiology at Harvard Medical
School. When under general anesthesia, an electroencephalogram, or EEG test, shows that
brain activity decreases down to levels very close to what we expect to see in cases of brain-stem
death. It's no wonder patients find the euphemism “put to sleep” to be a less scary description!
So, what does it actually feel like to get “put under” with general anesthesia?
Donna Penner's story provides a glimpse into the mysterious experience of being under
anesthesia - as well as a potent warning about how sometimes, things can go terribly, terribly wrong.
Donna, a 45 year old mother from Manitoba, Canada, had been experiencing some worrying
and unexplainable symptoms, so her doctor recommended an exploratory abdominal surgery
to see if they could find the cause of her mysterious issues.
On the day of her surgery, Donna was understandably nervous to be “put under”, but
she was eager to get to the bottom of her unusual symptoms. She met with her anesthesiologist, who
talked her through the process and assured her he would be by her side the entire time. Since Donna
didn't have any of the risk factors that could lead to a complication - she was a nonsmoker,
not overweight, with no underlying medical conditions - he assured her that things should
go smoothly, and that she wouldn't remember a thing when she woke up after the operation.
The only downside was that Donna had to fast for 6 hours before her surgery to ensure that
her stomach was empty and reduce the risk of vomiting or choking while she was under.
Finally, Donna was prepped for surgery and wheeled into the operating room,
where she was greeted by her anesthesiologist. As the surgeon was busy getting prepared for the
operation, the anesthesiologist placed a mask over Donna's mouth and administered a cocktail
of hypnotic agents, opioids, muscle relaxants, sedatives and cardiovascular drugs to Donna.
He held her hand and comforted her as she drifted into unconsciousness before inserting a breathing
tube down her throat to help her breath and prevent choking, since the anesthesia relaxes
breathing and coughing reflexes. He also placed 3 sticky patches on Donna's chest connected to an
electrocardiogram, or ECG machine, to monitor her heart rate, secured a blood pressure cuff on her
arm, and clipped a pulse oximeter to her finger to monitor the oxygen level in Donna's blood.
True to his word, Donna's anesthesiologist would remain by her side throughout the
entire operation, carefully monitoring her stats and ensuring that she was
getting a continual dose of anesthesia drugs. But, despite his watchful eye,
there was one thing her anesthesiologist couldn't see - Donna was actually awake.
Horrifically, Donna had woken up just before the surgeon was about to make his very first cut.
She was fully conscious but immobilized, unable to speak or to signal to the room
full of doctors and nurses that she was awake and aware. She remained frozen in place on the
table as the surgeon sliced open her abdomen and explored her insides, poking and prodding at her
organs for hours. All the while, Donna could feel everything - every excruciating slice,
every horrible movement. She was in terrible, agonizing pain, and she was helpless to do
anything about it - she couldn't move or scream, and she was sure she was going to die. “I thought,
‘This is it,” says Donna. “This is how I'm going to die, right here on the table, and my family
will never know what my last few hours were like because no one's even noticing what's going on.'”
Miraculously, Donna survived her ordeal, though her recovery was long and painful.
Even once her body had healed, the experience left her with lasting psychological scars.
She developed severe Post Traumatic Stress Disorder, or PTSD, as a result of her horrific
experience on the operating table, and suffered from anxiety and panic attacks for years.
Donna remembers having a full blown panic attack one day when out shopping. She had stayed in the
car while her daughter quickly ran into the store, but when Donna realized that the car
doors were locked and she was trapped inside, it triggered an intense flashback to the day,
more than a decade prior, when she had been trapped and helpless on the operating table.
To this day, Donna cannot stand to wear any clothing that is tight around her neck, because
it makes her feel like she can't breath and takes her back to her ordeal in the operating room.
No one knows exactly why Donna woke up during her surgery, but it's estimated that as many
as 1 in every 1,000 patients are believed to wake up at some point while under general anesthesia.
More recent studies show that this number may be even higher. It's yet another of the
many mysteries surrounding anesthesia and exactly how and why it works - or doesn't.
Thankfully, Donna's terrifying experience is rare. For most patients who get “put
under” with general anesthesia, the process goes smoothly and their surgeons are able
to do their work without the patient having any awareness of the trauma happening to their body.
When they wake up, usually about an hour after the anesthesiologist stops administering the drugs,
they have no memory of the experience. It can actually feel quite surreal - the last
thing they remember is the mask over their face as they drift off into unconsciousness,
and when they come to in the recovery room it can feel like no time at all has passed.
It's normal to feel a little “out of it” as the anesthesia wears off - patients can feel
emotional or loopy, may lack inhibitions or behave in an exaggerated manner,
and can have slurred speech for a few hours after anesthesia. If everything went smoothly,
it can actually be quite funny - at least for their loved ones and nurses. The process of coming
out of anesthesia is medically quite similar to the experience of a patient who has woken up from
a vegetative state, which makes sense when we think about the fact that being under anesthesia
is essentially being in a medically-induced coma. The stages of recovery are pretty much the same,
though they happen quite a bit faster when coming out of anesthesia.
Side effects are common after undergoing anesthesia. Most of them are not serious and
will go away on their own within a few hours to a few days. It's normal to experience vomiting,
dizziness, and headaches after waking up from anesthesia, and a sore throat or even a chest
infection can be expected as a result of the breathing tube that was used during the procedure.
Confusion and memory loss are also quite common, and usually resolve quickly. That said,
in very rare circumstances, more serious side effects can occur,
including nerve damage, a severe allergic reaction to the anesthesia drugs,
awareness during surgery - like what Donna experienced - and even, sometimes, death.
Even though we know very little about how anesthesia actually works, it's an essential - if
imperfect - tool in modern medicine, and it's not likely going anywhere anytime soon. Thankfully,
scientists are working hard to improve our understanding of how anesthesia works,
and to develop more advanced techniques to make anesthesia more effective and more targeted.
Anthony Hudetz works in the Department of Anesthesiology at the Medical College of
Wisconsin, Milwaukee, and he is just one of the many researchers working to better understand
and improve anesthesia. Hudetz imagines a world where anesthesia is less of a “hammer to the head,
knock-out” experience, and more of a delicate and specific tool.
"We can also develop better anesthetic drugs that would target consciousness itself,
because today's anesthetics affect every cell in the body," Hudetz says. "They suppress the heart
and they affect all the major organs; they affect the circulation; they suppress blood pressure,
heart rate. And this is tolerable but we mostly operate on injured people and sick people,
and in that case these side effects of anesthetics are undesirable and should be minimized."
Anesthesia researchers are learning a lot by collaborating with coma and sleep researchers
to share knowledge and develop more delicate tools that can help across multiple fields.
Hopefully, this will mean fewer harrowing stories like Donna's, and one day soon,
we might actually know how anesthesia puts you to sleep.
If you thought this video was shocking, you'll want to be sure and check out our other videos,
like this one called “The Most Painful Things A Human Can Experience”. Or,
maybe this other video is for you.
