What does it feel like to wake up from anesthesia? Will there be hallucinations?

Some time ago, a primary school math teacher started teaching by himself while the anesthetic had not worn off after surgery. He taught the children to count the little stars in a daze. It was so cute (please imagine a male teacher with a slightly coquettish tone)~

Later, a Beijing woman raised her empty hands to "play with her phone" after the operation. The medical staff smiled and asked her, "Do you have a signal on your phone?" She looked at it very seriously and said "I see" (she actually answered that she saw a signal, so it was probably full), and the medical staff were all amused~

Image source: Weibo

What kind of mysterious operation is this? Could it be that people's true nature is revealed unconsciously when the anesthesia has not worn off? Can anesthesia also have the effect of embarrassing people?

What is anesthesia?

Whether it was the math teacher counting little stars or the Beijing woman playing with her phone, both of them happened when the anesthetic effect had not yet worn off after the operation. In fact, this phenomenon is not uncommon.

Anesthesia is indispensable for many surgeries. The use of anesthetics greatly reduces the pain of patients during surgery. Anesthetics enter the human body through different methods (including inhalation, intravenous or intramuscular injection, and rectal infusion, etc.), inhibit the central nervous system, and cause the patient to lose consciousness.

General anesthesia means that there is no pain in the whole body during the operation; local anesthesia means that the local anesthetic is injected into the corresponding part of the body, causing the spinal nerves or finer peripheral nerve endings to be blocked; combined anesthesia means that two or more anesthetics are used in combination. Anesthetics are divided into general anesthetics and local anesthetics. General anesthetics are referred to as general anesthetics. This type of drug can cause different degrees of loss of sensation and consciousness in the human body. After the effect of the drug wears off, sensation and consciousness can be restored.

Depending on the method of administration, general anesthetics can be divided into inhalation anesthetics and intravenous anesthetics. Intravenous general anesthetics include barbiturates and non-barbiturates. The anesthesia takes effect quickly, and the anesthetic effect occurs as soon as the drug reaches the brain from the injection site.

Image source: Clinical Anesthesiology

Local anesthetics also block nerve impulses and nerve conduction. Compared with general anesthetics, local anesthetics act completely and reversibly on the site of administration. Of course, the effects of local anesthetics are not limited to the local area. When local anesthetics are absorbed or directly injected into the blood circulation, they will produce systemic effects.

Moreover, when the level of local anesthetics in the blood is relatively high, it can affect the functions of the central nervous system, cardiovascular system and other organs. So is the embarrassment of some people after surgery related to anesthetics? It is true!

The embarrassment after surgery is caused by the anesthetic. General anesthetics have the effects of blocking memory, relieving pain and causing unconsciousness. Patients who receive general anesthesia may experience symptoms such as talking nonsense, confusion, dizziness, and fatigue after surgery. This is a phenomenon caused by the inhibition of cerebral cortex function caused by anesthetics, and they can gradually return to normal after the drug is withdrawn.

Moreover, the patient may experience hallucinations during the process of waking up from anesthesia, just like dreaming! (So, talking nonsense is normal, but the content of talking nonsense varies from person to person. During this period, be careful of uncontrolled social death~) If local anesthetic poisoning occurs, the patient will also show mental excitement, euphoria, and hyperactivity, followed by tongue numbness, dizziness, mild headache, visual impairment and other symptoms. This requires a doctor to deal with it!

Is the social death after surgery all to blame on the anesthetic? The anesthetic said: I can’t take all the blame. Haven’t you heard of a disease called postoperative cognitive dysfunction? (Maybe some of you really don’t know…)

What is postoperative cognitive dysfunction?

Postoperative cognitive dysfunction refers to central nervous system complications that occur after general anesthesia. It often occurs in elderly patients undergoing major or emergency surgery, and its clinical manifestations include anxiety, mental confusion, memory impairment, and even personality changes. Some people also believe that postoperative cognitive dysfunction is a reversible, fluctuating acute mental disorder syndrome.

A large number of surveys have shown that postoperative cognitive dysfunction mainly occurs in elderly patients over 65 years old, and is most common after major surgeries such as heart surgery (an article reports that the overall incidence of postoperative cognitive dysfunction after heart surgery is 10%-50%).

Anesthesia may be one of the main causes of postoperative cognitive dysfunction. It has been confirmed that extremely low levels of anesthetic residues can affect neurological function. Scopolamine used before surgery has a significant amnesia effect; isoflurane can weaken a person's orientation and comprehension. Some scholars have also confirmed that a person's visual synthesis, short-term memory, cognition, and motor skills will decline after inhaling trace amounts of halothane and nitrous oxide. In addition, anesthetics can inhibit the release of the excitatory neurotransmitter acetylcholine, block acetylcholine receptors, and affect the release of other neurotransmitters, thereby impairing cognitive function.

In addition to the drug effects of the anesthetic itself, the surgery itself is also one of the reasons why patients experience postoperative cognitive dysfunction. In particular, if hypotension, hypoxia, etc. occur during the surgery, the patient is more likely to experience postoperative cognitive dysfunction.

Strong and persistent stress reactions may affect memory and learning ability, and damage the hippocampus, the main site of learning and memory. There is an area in the hippocampus that is closely related to cognitive function. People have found that there are adrenocortical hormone receptors in this area. When the body is stressed, the secretion of glucocorticoids increases and can bind to the receptors in the hippocampus. Long-term high levels of glucocorticoids will eventually cause damage to hippocampal neurons, leading to cognitive dysfunction.

As the aging population continues to increase, more elderly patients may need surgery, and postoperative cognitive dysfunction will have a great impact on the patient's quality of life. The prevention, diagnosis and treatment of postoperative cognitive dysfunction need to be further improved.

Of course, whether it is the unconsciousness caused by temporary anesthetics or postoperative cognitive dysfunction, it shows that there is a bug in our body. Although the embarrassing state after surgery looks very funny, Tadpole still hopes that everyone will be healthy and be a happy foodie in 2022!

Finally, let me ask you: Have you ever been under anesthesia for surgery? Have you ever done anything strange after waking up?

Reviewer: Yin Tielun, associate chief physician of the Department of Neurology, Airport Campus, Peking University Third Hospital.

Tadpole Musical Notation original article

Editor/Heart and Paper