Understanding your anaesthetic
Anaesthesia
Anaesthesia means using medicines to block pain and keep you comfortable during your operation. There are several types. Your anaesthetist will discuss which is most appropriate for you and your surgery.
General anaesthesia
You are completely unconscious for the operation. Medicine is given through a drip in your arm, and you breathe with the help of an airway device placed once you are under anaesthesia. You wake up in the Post Anaesthesia Care Unit (PACU) when the operation is finished. This is the most common type for major surgery.
Spinal or epidural
An injection into your back numbs the lower half of your body. You stay awake or are given light sedation to keep you comfortable. This is commonly used for hip and knee replacement, some bladder surgery, and some bowel operations. The numbness wears off gradually over a few hours after surgery. Sometimes a spinal or epidural is combined with a general anaesthetic for major chest or abdominal surgery, to provide pain relief after the operation.
Nerve block
A targeted injection of local anaesthetic near a specific nerve numbs just one area (for example, your arm, shoulder, or leg). Nerve blocks are often used alongside general anaesthesia to reduce pain after the operation and reduce the need for strong opioid pain relief.
Sedation
You receive medication through a drip to make you relaxed and drowsy. You remain breathing on your own and can still respond. Used for some minor procedures, scopes, and operations under local anaesthetic where a degree of relaxation is helpful.
What to tell your anaesthetist
Before your operation, make sure your surgical and anaesthetic team knows about all of the following:
- Allergies, especially to medicines, latex, iodine, or any previous reaction to an anaesthetic
- All supplements, vitamins, herbal products, and over-the-counter medicines, including things you might not think of as medicines
- Recreational drug use. This is confidential and is essential for safe anaesthetic planning
- Previous anaesthetic problems, including nausea, awareness, slow waking, or any family history of anaesthetic reactions (particularly malignant hyperthermia)
- Dental work: loose teeth, crowns, caps, veneers, or a bridge at the front of your mouth
Common questions
Anaesthetic awareness (waking up or having any awareness during a general anaesthetic) is very rare. Overall, it occurs in around 1 in 20,000 cases with modern techniques. The risk can change depending on the type of operation and anaesthesia. Your anaesthetist monitors the depth of your anaesthetic continuously throughout the operation using dedicated monitoring equipment. If you are worried about this, please raise it at your pre-assessment appointment. Your anaesthetist can discuss the precautions used.
Post-operative nausea and vomiting (PONV) is common after surgery but very manageable. Your anaesthetist will give you anti-nausea medication routinely during and after the operation. If you have a strong history of PONV, motion sickness, or have felt very sick after a previous anaesthetic, tell your team at your pre-assessment. They can plan extra precautions, including additional anti-nausea medications and changes to your anaesthetic technique.
Most regular medications should be taken as usual on the morning of surgery with a small sip of water, even if you are fasting. However, some medications (particularly diabetes medications, blood thinners, and certain newer drugs) need specific adjustments. Your surgical and anaesthetic team will give you written instructions. See our Medications guide for more detail. If in doubt, contact your pre-assessment clinic or GP.
Feeling anxious before surgery is completely normal. Most patients do. It helps us to look after you better if you talk about your concerns with your anaesthetist at your pre-assessment appointment. Understanding exactly what will happen often helps significantly. If your anxiety is significant, ask your GP or surgical team about additional support options.
A pre-assessment appointment happens before your operation. A specially trained nurse and anaesthetist will review your general health, current medications, and any test results. You may have blood tests, an ECG, or other checks done at this appointment. It is also your opportunity to ask questions about your anaesthetic and what to expect on the day. Building your prep plan on this website beforehand can help you make the most of the appointment.
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