General, spinal or local anaesthetic: the differences and how the anaesthetist chooses

Anaesthesia is a procedure that removes the feeling of pain during an operation or procedure. General and spinal anaesthetics and sedation are managed by a doctor specialising in anaesthesiology and resuscitation, who monitors the heart, breathing and blood pressure throughout. For smaller procedures, a local anaesthetic is usually given by the doctor carrying out the procedure, and an anaesthetist becomes involved when the doctor decides it is needed. There are several main types:

• General anaesthetic: the patient is unconscious, feels no pain and does not remember the operation.
• Spinal anaesthetic: the medicine is injected into the lower back, so the lower half of the body temporarily feels no pain. The patient is usually awake.
• Local anaesthetic: only a small area at the site of the procedure is numbed. The patient is awake.
• Analgosedation: calming medicines and painkillers are given into a vein. The patient is relaxed and drowsy and usually breathes on their own.

A spinal anaesthetic is a form of regional anaesthesia, as are an epidural, where the medicine is given through a thin tube in the back, and nerve blocks. Regional anaesthesia switches off the feeling of pain in one part of the body, for example from the waist down or in an arm, and the patient can stay awake. The types are often combined, for example a local anaesthetic with analgosedation, or a spinal anaesthetic with light sedation.

In children, the type of anaesthetic and the fasting instructions are adjusted to the child's age and weight, and the anaesthetist gives the exact instructions. One example is sedation or anaesthesia for an MRI scan, which is covered in more detail in the article on MRI scans for children.

Before it starts, a cannula, a thin plastic tube for medicines and fluids, is placed in a vein in the arm. Sticky pads (electrodes) are placed on the chest to monitor the heart, a clip on a finger measures the pulse and the oxygen level in the blood, and a cuff on the upper arm measures blood pressure. The anaesthetic medicine is usually given through a vein, and sometimes it is breathed in through a mask. The patient falls asleep within a short time. Once the patient is asleep, breathing is usually secured with a tube in the windpipe (intubation) or a special mask, and a machine helps with breathing if needed. Throughout the operation, the anaesthetist monitors the patient's condition and gives more medicine as needed. In the price list, a general anaesthetic with a tube in the windpipe is marked with the abbreviation OETA (from the Serbian for general endotracheal anaesthesia).

Once the medicines are stopped, the patient usually wakes up within a few minutes. In the first few hours, drowsiness, thirst, a dry or sore throat, shivering and sometimes nausea are common. These usually pass within a few hours, and there are medicines for nausea and pain. The effects of the anaesthetic medicines can be felt for up to 24 hours.

A general anaesthetic is most often used for larger abdominal operations, for laparoscopic (keyhole) operations and for longer procedures.

The patient sits up or lies on their side and curves their back. The skin of the lower back is numbed first. The anaesthetist then uses a fine needle to inject the medicine below the point where the spinal cord ends, into the fluid surrounding the nerve roots. Within a few minutes, the legs feel warm, heavy and free of pain, and for a while they cannot be moved. Touch and pressure may still be felt, but not pain. The operation site is screened off with a drape and, if the patient wishes and the doctor agrees, light sedation can also be given.

A spinal anaesthetic is most often used for procedures on the lower half of the body, for example inguinal hernia repair or haemorrhoid surgery, some urological and gynaecological operations and procedures on the legs. Feeling and movement in the legs return gradually, usually within a few hours, and the patient is monitored until then.

Possible short-term side effects are a drop in blood pressure, nausea, shivering and difficulty passing urine in the first few hours. Less often, a headache develops that gets worse when the patient sits or stands up and eases when they lie down. It can also appear a day or two after the procedure, when the patient is already at home. This kind of headache should be reported to a doctor, as there are ways to relieve it.

With a local anaesthetic, the medicine is usually injected into the skin and tissue around the site of the procedure. There is a needle prick and a brief stinging, and after that the area is numb. Touch, pressure and pulling may be felt, but not pain. The patient is awake and can talk to the doctor. The numbness usually wears off within one to a few hours. According to the Maja Hospital price list, procedures done under a local anaesthetic include, for example, minor surgical procedures, draining small abscesses, and umbilical and inguinal hernia repair.

Analgosedation is a combination of calming medicines and painkillers given into a vein. The patient is relaxed and drowsy, usually breathes on their own and can answer questions, and often remembers little of the procedure afterwards. It is most often combined with a local anaesthetic, so no pain is felt at the site of the procedure. During sedation, breathing, pulse, blood pressure and the oxygen level in the blood are monitored.

In the Maja Hospital price list, analgosedation is listed for some hernia operations and for hidradenitis (an inflammatory condition of the sweat glands with pus-filled lumps). The plastic surgery price list has separate items for sedation, analgosedation and monitoring by an anaesthetist. Deep sedation is something different: the patient sleeps more deeply and does not respond to questions, so breathing is monitored even more closely. The radiology price list has a separate item for deep sedation during an MRI scan, for people who cannot stay still in the scanner for long.

There is no single answer to whether a general or a local anaesthetic is better: no type of anaesthetic is better than another in itself. The one chosen is the one that suits the procedure and the health of the individual patient. The anaesthetist agrees the proposal with the doctor carrying out the procedure (the surgeon, urologist or gynaecologist), after examining and talking with the patient. For smaller procedures done under a local anaesthetic alone, the decision is usually made by the doctor carrying out the procedure. The choice usually takes into account:

• the type, site and expected length of the operation
• heart and lung conditions, blood pressure, diabetes, kidney and liver disease
• regular medicines, especially blood thinners
• spine problems, previous spinal surgery and blood clotting disorders
• previous anaesthetics, allergies and reactions to medicines, as well as serious reactions to anaesthesia in blood relatives
• body weight, snoring and pauses in breathing during sleep
• test and examination results
• the patient's wishes and worries

For some procedures the choice is clear. Laparoscopic operations are usually done under a general anaesthetic. For others, such as open inguinal hernia repair, more than one type of anaesthetic is possible, so the decision is made after the examination. The plan can also change during the procedure: if a spinal or local anaesthetic does not work well enough, the anaesthetist can switch to a general anaesthetic. This is discussed in advance, before the consent form for anaesthesia is signed.

At the pre-operative assessment, the anaesthetist talks with the patient and reviews their test results. Blood tests and an ECG are usually needed, and sometimes a chest X-ray or the opinion of another specialist. Which tests are needed depends on age, health and the type of procedure. It is useful to bring a list of all the medicines you take, including herbal remedies and supplements, and any previous test results.

Fasting before an anaesthetic is important because the reflexes that protect the airways are weakened under anaesthesia, so stomach contents can get into the lungs. The anaesthetist gives the instructions and they should be followed exactly. Usually the following applies:

• no solid food, milk or thick drinks for six to eight hours before the anaesthetic
• water and other clear fluids, for example tea without milk, can usually be drunk up to two hours before the procedure, but milk and coffee with milk are not clear fluids
• some regular medicines are taken in the morning with a sip of water, and some are temporarily stopped, especially blood thinners and diabetes medicines, but only as agreed with the doctor
• the anaesthetist should also be told about weekly injections for diabetes or weight loss, as they can slow down how quickly the stomach empties
• jewellery, piercings, nail varnish and make-up are removed before the procedure, and dentures and contact lenses as instructed by the staff
• who will take the patient home is arranged in advance

If the patient has eaten or drunk anything after the agreed time, they should tell the anaesthetist before the procedure. The fasting instructions usually also apply to a spinal anaesthetic and analgosedation, because it may be necessary to switch to a general anaesthetic during the procedure. For smaller procedures under a local anaesthetic alone, fasting is often not needed, but the doctor's instructions still apply.

After a general or spinal anaesthetic and after sedation, the patient should not drive, operate machinery, drink alcohol or sign important documents for at least 24 hours. The anaesthetist gives the exact time. It is a good idea for someone to stay with the patient on the first night. Hoarseness and a sore throat from the breathing tube usually pass within a day or two.

In older people, temporary confusion or forgetfulness (post-operative delirium) sometimes develops after an operation. It usually passes within a few days, and less often lasts longer. It does not depend only on the anaesthetic, but also on the operation itself, pain, medicines and the hospital stay. It helps if family stay with the patient and if the patient has their glasses and hearing aid, if they use them. If there are already memory problems, the anaesthetist should be told at the assessment.

Serious complications of anaesthesia are rare. The anaesthetist discusses the risks that apply to the individual patient at the pre-operative assessment. After discharge, the patient should contact their doctor or the hospital where they had the operation as soon as possible if they develop a severe headache or a high temperature, or are unable to pass urine. After a spinal anaesthetic, severe back pain at the injection site, numbness or weakness in the legs that does not go away, and loss of bladder or bowel control should be reported to a doctor without delay, as they can be a sign of rare bleeding or infection around the spine. In the case of difficulty breathing, chest pain or loss of consciousness, call the emergency ambulance service on 194 without delay.