General Anesthesia: A Comprehensive Guide to Medically Induced Unconsciousness

A secure and well - controlled medical practice, general anesthesia causes a brief loss of consciousness; a patient feels no awareness, no discomfort, and cannot move during an operation. 

Overview 

General anesthesia is a medically induced, managed unconsciousness which is necessary for many operations. It is a very sophisticated procedure which ensures the patient is completely unaware, has no pain, and is motionless during the surgery – this is done using strong medicines, including some given into a vein and certain gases for inhalation. 

An anesthesiologist gives these, and consistently watches for their effects. The main intention of general anesthesia is to give the surgeon the very best conditions to carry out a complicated operation, both safely and efficiently. It also absolutely guarantees the patient’s complete safety, ease, and stability from when they arrive in the operating room, to recovery in the post-anesthesia recovery room. 

Modern anesthesiology is a very advanced, and safe, field of medicine. During surgery, the anesthesiologist is the patient’s representative, functioning as an exclusive intensive care doctor for that individual. Using the newest equipment, they quickly observe all of the body’s key signs, constantly changing the level of unconsciousness and reacting to the body’s responses to surgical stress. 

It is understandable to worry about “going under”. However, it is important to understand that general anesthesia is a normal and very safe process; for the majority of otherwise healthy patients, the dangers are very small. This complete guide will look at the science of anesthesia, covering the procedure’s many parts, the medications used, and a clear description of what to expect during your operation. 

What Anesthesia Is: A Detailed Look at the Neurophysiological Procedure 

Being under general anesthesia is much more than merely being asleep. It is, in fact, a deep, pharmaceutically created sleep which can be reversed. The procedure needs a number of vital parts, and an anesthesia expert carefully mixes different drugs to achieve all of these at the same time. 

The Four Parts of General Anesthesia 

1. Amnesia (Loss of Memory): This makes sure you do not remember the surgery, or what was done during it. Medicines stop the brain from making new memories. 
2. Analgesia (Pain Relief): The surgeon’s cuts or handling of tissues make powerful pain signals. Strong painkillers – often opioids – are used to stop these signals getting to the brain, and to reduce the body’s reaction to the stress of the operation. 
3. Akinesia (Immobility): The patient must be completely still during careful surgery. The main anesthetic drugs help to prevent movement; but often, for stomach or chest procedures, extra drugs – muscle blockers or relaxants – are given, which briefly paralyse the body’s muscles. 
4. Anxiolysis and Unconsciousness: This is when awareness stops, the state of truly being “asleep”. This happens when anesthetic medicines slow the central nervous system – the body’s main control centre – and affect the brain areas which are responsible for wakefulness. 

The Neurobiology of Anesthetic Effect 

The exact way that anesthetic medicines cause unconsciousness is still the subject of much scientific research, but is known to involve contact with certain neurotransmitter receptors in the brain. 

1. Increasing Inhibition (The “Brakes”): The most important way for many anesthetic drugs – propofol, and the inhaled gases, for instance – is their ability to make stronger the effect of an inhibitory neurotransmitter, Gamma-Aminobutyric Acid, or GABA. GABA is the brain’s main “braking” system. By increasing the sensitivity of GABA receptors, anesthetic drugs increase the inhibitory tone throughout the brain, effectively lowering neuronal activity and resulting in sedation and unconsciousness. 
2. Blocking Excitation (The “Accelerator”): Other medicines, like ketamine, work by stopping the action of an excitatory neurotransmitter – glutamate – at its NMDA receptor. By blocking this main “accelerator” system, these drugs also help to make the anesthetic state. 

The anesthesiologist’s skill is in using a carefully balanced combination of drugs which act on these different routes, to create a smooth, stable, and safe anesthetic experience, made to order for the individual patient and the specific surgical operation. 

The Anesthesiologist’s Toolkit: A Range of Medications 

Contemporary general anaesthesia isn’t brought about by one medication, but by a thoughtfully selected group of drugs, each having a particular function. 

Intravenous Induction Drugs 

These are quick medications administered via an IV to swiftly and easily move patients from being awake to unconscious at the start of a process. 

• Propofol: Globally, this is the induction drug used most often. A milky-white liquid, it works very quickly and doesn’t last very long. Patients will often say they felt a nice sensation as they fell asleep. 
• Etomidate: This drug is recognised for its cardiovascular steadiness and is often used for seriously unwell people, or those with heart issues. 

Ketamine: An unusual drug that gives substantial pain reduction, as well as causing a state of dissociative anaesthesia. 

Inhaled Maintenance Drugs 

After the patient is unconscious, the anaesthetic condition is usually sustained for the length of the operation using strong anaesthetic gases or vapours which are passed through a breathing tube. 

• Sevoflurane and Desflurane: The most prevalent current inhaled drugs. They are released from a specific vaporiser on the anaesthesia machine, combined with oxygen, and breathed in by the patient. The anaesthetist can, with great accuracy, manage the amount of gas to subtly adjust the depth of the anaesthesia, as it happens. 

Analgesics (Opioids) 

These are strong pain-reducing medicines used during all of the operation. 

• Fentanyl and Remifentanil: These are very strong, fast-acting opioids given intravenously to halt the body’s hormonal and cardiovascular stress reaction to the painful surgical event. 

Neuromuscular Blocking Drugs (Muscle Relaxants) 

For many types of surgery these drugs are vital, to make sure the patient stays completely immobile, and to give the surgeon the best possible conditions for operating. 

They function by blocking the signal at the neuromuscular junction – the point where the nerve and the muscle meet. They do not cause unconsciousness, or pain relief; they are only used when the patient is already fully anaesthetised. 

The Patient's Journey Through General Anesthesia 

Receiving general anesthesia is a very carefully planned series of steps, and your safety is the most important thing to us throughout the entire process. 

The Essential Pre-Anesthesia Evaluation 

Your anesthesia experience starts days or weeks before your operation with a Pre-Anesthesia Check-up – a PAC. This is an important meeting with someone from the anesthesia staff. 

• Review of Medical History: The anesthesiologist will go over your medical history in detail; this includes any problems with your heart, lungs or kidneys, previous operations, and any history of issues with anesthesia in you or your family. 
• Medicines and Allergy Check: You need to give a full list of all medicines you take, any supplements, and any allergies you have. 
• Physical Check: The doctor will listen to your heart and lungs, and do an airway exam – checking how wide your mouth opens, how your neck moves, and the size of your jaw – in order to work out the best way to control your breathing during the operation. 
• ASA Grouping: From this evaluation, you’ll be given an American Society of Anesthesiologists ASA physical status rating; this is a number which helps us put a category on your overall health and the risk of your operation. 
• Not Eating or Drinking: You will be given very specific, and strict, directions about when to stop eating and drinking before your operation. This is a very important safety step to avoid the chance of aspiration – when the contents of your stomach go into your lungs while you are unconscious. 

The Day of Surgery: Starting, Continuing, and Finishing 

1. In the Pre-Operation Area: On the day of your operation, you will see your anesthesiologist again. They will talk through the plan with you, and answer any last questions. A drip will be put into your arm or hand. 
2. Going Into the Operating Room: You will be taken to the operating room, and linked up to a set of standard safety monitors – an ECG, a blood pressure cuff, and a pulse oximeter. 
3. Starting Anesthesia (“Going to Sleep”): The anesthesiologist will begin by giving you oxygen to breathe through a mask. They will then give you the medicine to start anesthesia through your drip. You will feel a warm feeling, and you will fall asleep very quickly and easily in around 30 seconds. 
4. Keeping the Airway Clear: When you are completely unconscious, the anesthesiologist will put in a device to keep your airway open and safe. This is usually either an endotracheal tube – a tube put through your mouth into your windpipe – or a laryngeal mask airway, a soft mask which sits over the top of your windpipe. You will be connected to a ventilator which will breathe for you during the operation. 
5. Continuing Anesthesia: All through the operation, the anesthesiologist will be at your head, constantly watching your vital signs, giving the gas to keep you asleep, and giving any medicines you need to keep you in a stable and safe condition under anesthesia. 
6. Coming Round (“Waking Up”): As the operation is ending, the anesthesiologist will start to turn off the anesthetic gases. They will give you medicines to cancel out any muscle relaxing effects. As the anesthesia wears off, you will slowly start to breathe on your own again, and slowly start to wake up. When you are breathing well, and starting to follow directions, the breathing tube will be taken out. 

The Post-Anesthesia Care Unit (PACU) 

Right after your operation, you’ll be moved to the Post-Anesthesia Care Unit – this is the recovery room. 

1. Observation: Nurses with special training in this area will keep an eye on your breathing, pulse, blood pressure, and oxygen levels, whilst you come fully round. 
2. Dealing with Effects: Nurses will deal with any usual responses to anaesthetic, like sickness, discomfort or trembling, using suitable medicines. 
3. Going: You will stay in the PACU until you are fully conscious, your discomfort is at a level you can bear, and your important signs are firm; then you will be moved to your ward.  

Myths And Facts 

Myth: 

• Going under anesthesia is like being in a deep sleep. 

Fact: 

• Though it looks the same, general anesthesia is in reality a medically created coma – quite unlike ordinary sleep. It’s a carefully managed, and able to be turned around, condition of very great unresponsiveness, and is far more profound than any sleep phase. 

Myth: 

• It is very common to wake up in the middle of surgery. 

Fact: 

• Waking up during an operation is a remarkably unusual occurrence, and is called anesthetic awareness. Modern ways of checking on patients, including brain activity monitors like BIS in the more dangerous situations, allow anesthesiologists to get an accurate reading of how deeply someone is anesthetised, and to make sure they remain unconscious. It happens in approximately one case in 20,000. 

Myth: 

• I might say embarrassing things while I am under anesthesia. 

Fact: 

• Because you are totally unconscious during general anesthesia and your voice box is relaxed, you are unable to talk. Some patients will talk whilst coming round, but this will be in a secure and professional medical setting. 

Myth: 

• A lot of people never wake up from anesthesia. 

Fact: 

• This is a frequent worry, but the possibility of dying because of anesthesia in someone in good health who is undergoing scheduled surgery is very small in present-day medicine, and is generally given as less than one in 200,000. Anesthesiologists are specialist doctors who have been trained to stop this from happening. 

Your Safety is Our Highest Priority 

General anesthetic – a truly amazing achievement in modern medicine – allows for involved, and often, essential operations to be carried out. This is a controlled loss of awareness, and throughout it, a skilled, thoroughly-qualified professional will be in charge. The most vital part of this process is the confidence and exchange of information that exists between the patient and the anaesthetist: a full, candid talk during your consultation before the anaesthetic is given is the key to your safety, and to setting your mind at rest.  

At Fortis Healthcare, we pledge to give you the most secure, and best anesthetic treatment we are able to. Our team of experienced anaesthetists employs the newest equipment and methods proven by research, to fashion an anesthetic arrangement suitable to you, so that your operation is as secure, pleasant and untroubled as it may be.