When undergoing surgery, patients are given medication to induce a state of unconsciousness, commonly referred to as being “put to sleep.” This is done for several reasons:
Types of Anesthesia
There are three main types of anesthesia used during surgery:
- General anesthesia – induces a loss of consciousness and blocks pain sensations
- Regional anesthesia – blocks pain sensations in a specific region of the body
- Local anesthesia – blocks pain sensations in a small area of the body
General anesthesia causes you to become completely unconscious and unaware during your surgery. This state is also sometimes referred to as going under general anesthesia or being put to sleep for surgery.
How General Anesthesia Works
General anesthesia works through the use of medications that are injected through an IV and/or inhaled through a breathing mask or tube. It acts on the central nervous system to induce unconsciousness and prevent your brain from processing pain signals while you are under its effects.
There are three main types of medications used:
- Hypnotic agents – These induce unconsciousness, such as propofol or sevoflurane.
- Analgesics – These prevent pain sensations, such as fentanyl or morphine.
- Muscle relaxants – These cause temporary paralysis of the muscles, such as rocuronium or cisatracurium.
The combination of these three medication types provides pain relief, amnesia, muscle relaxation and loss of consciousness required for general anesthesia. The doses can be precisely controlled by the anesthesiologist to produce the optimum anesthetic state tailored for each patient and procedure.
The Process of Going Under Anesthesia
Here are the basic steps for how general anesthesia is administered:
- An IV is started, through which medications can be administered.
- Monitors are placed, such as blood pressure cuff, EKG leads, and oxygen saturation clip.
- Oxygen mask is placed to enrich the breaths with extra oxygen.
- The patient takes some deep breaths, often breathing an anesthetic gas.
- Medications such as propofol are injected through the IV, rapidly inducing unconsciousness usually within 30-60 seconds.
- Once unconscious, a breathing tube is inserted after giving muscle relaxing drugs.
- Additional analgesic and hypnotic agents are given to maintain anesthesia.
- At the end of surgery, the anesthetic agents are stopped and reversal agents given.
- The breathing tube is removed once awake, and the patient is transported to the recovery room.
Throughout the surgery, the anesthesiologist carefully monitors vital signs, makes adjustments as needed, and ensures the patient remains appropriately unconscious. This allows the surgeons to proceed safely with the operation.
Recovery from Anesthesia
After surgery is complete, the anesthetic agents are discontinued. The breathing tube is removed once the patient is awake and able to breathe on their own again.
Patients are then transported to the post-anesthesia care unit, also called the recovery room. Here they are closely monitored by nurses as the effects of anesthesia gradually wear off.
During this time you may experience:
- Drowsiness, sleepiness
- Disorientation, confusion
- Nausea, vomiting
- Sore throat from the breathing tube
- Chills, shivering
- Aches and pains from surgery
Medications are available to treat any discomforts. Most effects resolve within a few hours, but some grogginess and fatigue can persist for a day or two.
Risks and Side Effects
Modern general anesthesia is very safe, but does still carry some risks:
- Allergic reactions to medications – mild rash to life-threatening anaphylaxis
- Side effects – low blood pressure, nausea, vomiting, sore throat
- Breathing issues – hypoxia, lung injury, aspiration
- Heart problems – changes in heart rhythm, heart attack
- Stroke
- Cognitive dysfunction – postoperative delirium or long-term issues
- Death (very rare) – estimated mortality rate is just 1 death per 200,000 general anesthetics in healthy patients
However, the risks must be balanced with the benefits. Procedures such as surgery would often be impossible without general anesthesia. Overall, it is very effective and safe in most patients.
Your anesthesiologist will discuss risks specific to your health status when obtaining your consent before surgery. Let them know of any prior issues with anesthesia. Steps will be taken to reduce risks, and prepare equipment and medications to treat any complications.
Conclusion
General anesthesia provides a state of controlled unconsciousness that is essential for many modern surgical procedures. It allows the patient to be completely unaware during surgery. Anesthetic agents are carefully titrated to induce amnesia, analgesia, paralysis and loss of consciousness. This provides optimal operating conditions and an immobile patient for the surgeon. Recovery usually occurs within a few hours after surgery as the anesthetic wears off. While very safe, risks and side effects do exist, but these are uncommon in healthy patients. Overall, being “put to sleep” with general anesthesia is a very effective technique that enables many life-saving operations to be performed safely.