What is a general Anaesthetic
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What Is a General Anaesthetic?
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Most people will have a general anaesthetic (GA) at some point in their life. It is commonly used for many types of surgery, from emergency procedures like appendix removal to planned operations such as joint replacements.
A general anaesthetic is a controlled medical state where a patient is fully unconscious (asleep), pain free, and unaware of what is happening during surgery. While the patient is asleep, a specialist team carefully monitors their breathing, heart rate, blood pressure, and oxygen levels to make sure you stay safe.
Although it may seem simple from the outside, a lot of preparation, drugs, equipment, and trained staff are involved in giving a safe anaesthetic.
If youβre interested in the people behind the scenes in theatre, you may also want to read our guide on What is an Operating Department Practitioners. 
Below is a simple guide explaining how general anaesthesia works.
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The Triad of Anaesthesia
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General anaesthesia is often explained using something called the Triad of Anaesthesia.
This simply means there areΒ three main things anaesthetists aim to achieve during surgery.
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1. Unconsciousness
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- The patient must be completely asleep and unaware of the operation.
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2. Pain Relief
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- The body must not feel pain during the procedure.
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3. Muscle Relaxation
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- The muscles may need to be relaxed so the surgeon can safely perform the operation.
Together, these three elements allow surgery to be carried out safely and comfortably.
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Why Do We Use a General Anaesthetic?
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A general anaesthetic allows surgeons to perform operations that would otherwise be extremely painful or impossible.
Reasons a GA may be used include:
β’ The operation would be too painful while awake
β’ The patient needs to remain completely still
β’ The surgery is complex or takes a long time
β’ The patientβs breathing needs to be carefully controlled
β’ The patient is extremely unwell
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Pros and Cons of a General Anaesthetic
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Like all medical treatments, general anaesthesia has advantages and disadvantages.
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Advantages
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β’ The patient is fully asleep and unaware
β’ No pain is felt during the operation
β’ Surgeons can perform complex procedures
β’ The breathing and airway can be controlled safely
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Disadvantages
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β’ It takes longer to recover compared to some other types of anaesthesia
β’ Some patients feel sick or dizzy afterwards (However we try and minimise this using anti sickness drugs.
β’ Patients usually cannot eat or drink before surgery
β’ There can be other risks involved.
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Risks of a General Anaesthetic
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General anaesthesia today is very safe, especially with modern monitoring equipment and highly trained staff.
However, like any medical procedure, there are some possible risks.
These may include:
β’ A sore throat from a breathing tube placed in the airway
β’ Feeling sick or vomiting after surgery
β’ Temporary confusion or drowsiness after waking up
β’ Very rarely, allergic reactions to medications
Most side effects are mild and go away quickly.
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Drugs Used in a General Anaesthetic
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Several different medicines are used together to safely create a general anaesthetic. Each drug has a specific job.
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Drugs That Send the Patient to Sleep
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The drugs used to send someone to sleep are called induction drugs. Induction simply means the start of the anaesthetic.
Common examples include:
β’ Propofol (White milky looking liquid)
β’ Thiopental
β’ Etomidate
These medicines work very quickly. Most patients fall asleep within seconds after the drug is given through a small plastic tube in the vein called a cannula (a thin plastic tube placed into a vein for giving medication).
If youβre preparing for hospital placement or theatre work then why not check out our Starter bundle which includes everything you will need to get you going.
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Pain Relief Medicines
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Even though the patient is asleep, the body can still react to pain. Because of this, strong pain relief medicines are given during surgery.
These drugs are called analgesics, which simply means pain relief medication.
Common examples include:
β’ Fentanyl
β’ Morphine
β’ Remifentanil
These medicines reduce the bodyβs reaction to pain during the operation and help keep the patient stable.
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Muscle Relaxant Drugs
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Some operations require the patientβs muscles to be completely relaxed so the surgeon can operate safely.
Muscle relaxant drugs temporarily stop the muscles from moving. This helps with placing breathing tubes and allows surgeons to operate more easily.
Examples include:
β’ Rocuronium
β’ Atracurium
β’ Suxamethonium
These drugs wear off after the operation or can be reversed using other medications.
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Equipment Used During a General Anaesthetic
Modern anaesthesia uses specialised equipment to help keep patients safe during surgery.
Anaesthetic Machine
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The anaesthetic machine is used to deliver oxygen and anaesthetic gases that keep the patient asleep during the operation.
The machine allows the anaesthetist to control exactly how much oxygen and anaesthetic the patient receives.
Take a look at our Idiots guide to the anaesthetic machine
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Ventilator
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AΒ ventilatorΒ is usually part of a modern anaesthetic machine and helps the patient breathe.
When someone is under a general anaesthetic, their breathing can become weaker or slower because of the drugs used. The ventilator gently moves air in and out of the lungs to make sure the body continues receiving enough oxygen. Check out our Anaesthetic Machine blog if you're interested in how the anaesthetic machine is checked and how it works. Click here
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Monitoring Equipment
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Throughout the operation, several monitors are attached to the patient.
These machines constantly measure important things happening in the body such as:
β’ Heart rate (how fast the heart is beating)
β’ Blood pressure (the pressure of blood moving through the arteries)
β’ Oxygen levels in the blood
β’ Respiratory rate (how fast you are breathing)
β’ C02 Output (the amount of C02 you are breathing out)
Check out our Blog on Monitoring during anaesthesia for a more in-depth look at how we monitor you.
If anything changes, the monitors alert the team immediately.
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Statistics Patients Are Usually Given
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Patients are often given simple statistics to help explain risks before surgery.
Typical examples include:
β’ About 1 in 10 patients may feel sick after surgery
β’ Around 1 in 100 patients may experience minor complications
β’ Serious complications are very rare
The exact risks depend on the patientβs health and the type of surgery.
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How Many General Anaesthetics Are Done Each Year?
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General anaesthesia is extremely common.
In the UK, it is estimated that over 3 million general anaesthetics are given every year across NHS and private hospitals.
Worldwide, it is estimated that over 300 million anaesthetics are performed annually.
Despite these huge numbers, anaesthesia remains one of the safest areas of modern medicine.
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Staff Involved in an Operating Theatre
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Delivering a general anaesthetic requires a trained team working together.
The team often includes:
β’ Surgeons
β’ Anaesthetists
β’ Operating Department Practitioners (ODPs)
β’ Scrub nurses
β’ Recovery nurses
β’ Health Care Assistants
Each role plays an important part in patient safety.
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The Anaesthetist
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TheΒ anaesthetist is a specialist doctor trained in anaesthesia and critical care.
They are responsible for:
β’ Assessing the patient before surgery
β’ Choosing the correct anaesthetic drugs
β’ Managing the airway (the passage that allows air into the lungs)
β’ Monitoring the patient during the operation
β’ Waking the patient safely afterwards
Find out more about what an anaesthetist actually does here
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The Operating Department Practitioner (ODP)
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TheΒ Operating Department Practitioner, often called an ODP, works closely with the anaesthetist.
ODPs prepare the equipment, check medications, and make sure everything is ready before the patient enters theatre.
During surgery they help manage:
β’ Monitoring equipment
β’ Airway equipment used to help patients breathe
β’ Anaesthetic drugs
β’ Emergency equipment if needed
Although patients may not always realise it, the ODP plays a vital role in safe anaesthesia and surgery.
If you would like to learn more about this profession, you can read our full guide explaining what an Operating Department Practitioner doesΒ
You can also find healthcare themed accessories and gifts for theatre staff here:
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Final Thoughts
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General anaesthesia allows surgeons to perform operations that save lives and improve quality of life.
While the patient sleeps, a skilled team carefully manages breathing, circulation, pain control and monitoring.
Thanks to modern drugs, advanced equipment and highly trained staff, general anaesthesia has become one of the safest areas of modern medicine.
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Don't listen to all the videos on tiktok that portray general anaesthetic in a bad light. It's simply not true and a very safe form of intervention.Β
Conduct your own research from reputable sources.