Anaesthesia is the deliberate use of medicines to prevent pain and distress during surgery, investigations or other medical procedures. It can involve loss of sensation in one small area, numbness across a larger region of the body, sedation, or controlled unconsciousness.
Anaesthesia is normally planned and delivered by an anaesthetist, supported by trained theatre and recovery staff. The choice of anaesthetic depends on the procedure, the patient's health, the urgency of treatment and the risks and benefits of each option.
Main Types
The main forms of anaesthesia are:
- Local anaesthesia: numbs a small area while the patient remains awake.
- Regional anaesthesia: numbs a larger part of the body, such as an arm, leg or lower half of the body.
- General anaesthesia: produces controlled unconsciousness so the patient is asleep and feels nothing during the procedure.
- Sedation: uses medicines to reduce anxiety and awareness, and may be combined with local or regional anaesthesia.
These methods can be combined. For example, a patient may have a general anaesthetic for an operation and a nerve block for pain relief afterwards.
Local Anaesthesia
Local anaesthesia is used for smaller procedures such as dental work, skin procedures, minor surgery and some diagnostic tests. The anaesthetic is usually injected or applied to the area being treated.
The NHS describes local anaesthetics as generally safe, with serious side effects being very rare. The patient usually stays awake and can go home sooner than after a general anaesthetic, depending on the procedure.
Regional Anaesthesia
Regional anaesthesia blocks sensation from a larger part of the body. Spinal anaesthesia, epidural anaesthesia and nerve blocks are common examples.
Regional techniques may allow surgery without full unconsciousness. They can also reduce pain after an operation. The Royal College of Anaesthetists notes that regional anaesthesia has benefits and risks that should be discussed as part of an individual anaesthetic plan.
General Anaesthesia
General anaesthesia uses medicines given through a vein, breathed in as gases, or both. The patient is unconscious and does not feel pain during the operation or procedure.
During general anaesthesia, breathing, oxygen levels, heart rate, blood pressure and other signs are monitored. Some patients need help with breathing while they are anaesthetised. The anaesthetist adjusts medicines and monitors the patient until the procedure is finished and recovery begins.
Before and After
Before anaesthesia, the anaesthetist or pre-assessment team reviews relevant medical history, allergies, medicines, previous anaesthetic problems and the planned procedure. Patients may be asked about smoking, alcohol, pregnancy, loose teeth, fasting and long-term conditions.
After the procedure, recovery staff monitor the patient as the anaesthetic wears off. Common short-term effects can include sleepiness, nausea, sore throat, shivering or temporary confusion. The expected recovery depends on the type of anaesthetic and procedure.
Risks
Modern anaesthesia is usually safe, but it is not risk-free. Risk varies by age, general health, urgency of surgery, airway difficulty, allergies, heart or lung disease, pregnancy, obesity and the type of operation.
Possible complications include nausea, vomiting, sore throat, dental injury, breathing problems, allergic reaction, nerve injury after some regional techniques, awareness under general anaesthetic, and rare life-threatening reactions. Serious events are uncommon, but they are the reason assessment, monitoring and trained anaesthetic care matter.
See Also
References
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