Most neurosurgical operations are carried out under general anesthesia. This means that you will be put to sleep using anesthetic drugs and woken up at the end of the operation.
Anesthetics for neurosurgery are given to very large numbers of patients who go on to make an excellent recovery without problems. They are given by an anesthetist (a doctor specially trained in anesthesia). We aim to assess each person on an individual basis beforehand. A general anesthetic may have slightly higher risks for some people with certain conditions, such as heart disease.
Pre-assessment clinic
You will be invited to our pre-assessment clinic before your scheduled operation so that we can assess your risk. A specially trained nurse will ask you about your medical history and perform some routine tests. If necessary you will be reviewed by a consultant anesthetist.  Tell them if you or any blood relatives have ever reacted to an anesthetic. Some people may need to have further investigations with other specialists.
The anesthesiologist will give you information about the anesthetic, ensure you are as fit as possible for surgery, and organize any further investigations you may need. Also, review your medications and explain which ones to take and which not to take before your surgery. You will get information on what time you need to stop eating and drinking before the operation.
The neuro anesthetists work as a team. If you meet an anesthetist in the clinic, they may not be the one who administers the anesthetic on the day of your surgery.
Operations carried out under sedation
Some neurosurgical operations are carried out under local anesthesia and sedation rather than general anesthesia. This means you will still be conscious but the anesthetist will give you drugs that calm and relax you.  The advantage is that the effects wear off very quickly after surgery. We may use this technique if we plan to send you home on the same day as your operation. We will discuss this with you if it applies to your operation.
On the day of your operation
If you are a non-emergency patient and have already visited the pre-assessment clinic, we can usually take you straight to our ‘day of surgery’ unit when you arrive for your operation. Here you will meet your anesthetist, who will explain the type of anesthetic you will receive and answer any further questions you may have. They are likely to assess your mouth opening, ask you if you have had any major dental work, and check your range of neck movement. They will also need to know if you are prone to sickness after anesthesia if you have allergies or cannot tolerate any medications. You must tell them if you have developed any signs of infection, such as a temperature, sore throat, runny nose, or cough.
Operating theatre
When it is time for your operation, you will be taken from the ward to the anesthetic room next to the operating theatre. We will carry out some further checks to confirm your identity and planned operation and to make sure that your completed consent form is correct. 
The anesthetist and the anesthetic assistant will attach routine monitoring and place a cannula (drip) in a vein, usually on your hand. If you are having a general anesthetic, they will use this to inject drugs to put you to sleep. After this, we will move you to the operating theatre for surgery. We may need to put additional cannulae (drips) in your arms or feet once you are asleep.
An anesthetist will stay with you for the entire operation. You will also receive painkillers, anti-sickness medications, and, if necessary, antibiotics, fluids, and other medications during the operation. 
Recovery room
After your operation, the anesthetist will turn off the anesthetic, wake you up, and take you to the recovery room. A nurse will look after you and make you as comfortable as possible. They will also record your blood pressure and heart rate and perform any other necessary checks. They will give you further pain relief if you need it. 
After an anesthetic
How you feel after having an anesthetic mostly depends on the type of operation you have had and the pain-relief medicine you are given.
General anesthetics can cause side effects which usually only last a few hours.
These include:
•        Feeling sick
•        Sore throat
You may feel tired or even exhausted for some days after the operation. After major surgery, this can last weeks or months. This is very unlikely to be caused by the anesthetic.
Common causes of tiredness after surgery include:
•        Worry before the operation
•        Poor sleep patterns
•        Pain
•        Blood loss causing anemia
•        The condition that needed the surgery
•        Poor eating and drinking
These will gradually improve as you leave the hospital and recover.
Complications of anesthesia
The anesthetists will make every effort to minimize the risks.
Possible complications include:
•        Damage to teeth or lips (rare)
•        Chest infection (rare)
•        Damage to eyes (very rare)
•        Nerve damage (very rare)
In very rare circumstances, there can be more serious complications such as death or brain damage. Rarely, do these occur directly as a result of anesthesia alone. The risk of death is around 1 in 100,000.