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Understanding Anaesthesia:
What to expect and how to prepare
What is General Anaesthesia (GA)?
General anaesthesia involves the administration of medications that induce a state of complete unconsciousness, ensuring the patient is unaware and unresponsive during a procedure. These anaesthetic medications can be delivered through a cannula inserted into a vein, or by inhaling anaesthetic gases. The combination of these methods ensures the patient remains completely unconscious throughout the surgical or medical procedure.
For which procedures might a GA be applicable?
General anaesthesia is applicable for a wide range of procedures, particularly those that are invasive or require the patient to remain completely still and unconscious. It is often used in combination with local anaesthesia, which numbs a small area of the body, or regional anaesthesia, where medication is injected near specific nerves to numb larger areas. This combination allows the patient to be completely unconscious and receive targeted pain relief, making it suitable for surgeries and medical interventions of varying complexity.
What should I do beforehand?
To prepare for a general anaesthetic, it is important to attend a nurse-led pre-assessment clinic if you are invited by the hospital. You should carefully follow any instructions from the medical team regarding fasting and whether you need to pause or adjust any medications before the procedure. Additionally, it is helpful to be in the best possible physical condition prior to surgery, which may include improving your fitness, eating a balanced diet, and reducing or quitting smoking, vaping, and heavy drinking. It’s also a good idea to prepare any questions you may have for your anaesthetist about the procedure and its associated risks.
When will I meet my anaesthetist?
You will typically meet your anaesthetist on the day of your procedure. However, for patients undergoing heart surgery, the anaesthetist will usually meet you the day before surgery when you are admitted to the ward. During this time, the anaesthetist will take a detailed medical history, including information about your current medications, allergies, and any previous experiences with anaesthesia. They will also explain your anaesthesia options, how the chosen anaesthesia will be administered, and discuss any specific risks that may be relevant to your situation.
How is anaesthesia delivered and monitored?
In some cases, patients undergoing major surgery may receive a 'premed' about an hour before the procedure to help them relax before the anaesthesia begins. Typically, general anaesthesia is administered in a room next to the operating room. One or more cannulae (drips) will be inserted into your arm, and the medication to induce unconsciousness will be delivered through these. For more complex surgeries, such as cardiac procedures, you may wake up with additional drips and tubes, including a cannula in your neck, chest drains, and a catheter for urine drainage. Throughout the procedure, your anaesthetist will closely monitor your condition for your safety and well-being.
What are the risks of anaesthesia?
The risks of anaesthesia vary depending on several factors, including your individual health, medical conditions, and the nature of the procedure you are undergoing. Your anaesthetist will discuss the specific risks that are more likely or significant for you based on your circumstances. If you are undergoing a cardiology or cardiac surgical procedure, there may be additional risks related to your anaesthetic, which will be explained if relevant. It is important to feel comfortable asking your anaesthetist about any concerns or worries you may have regarding the anaesthesia. The Royal College of Anaesthetists provides an infographic that outlines the general risks and side effects associated with general anaesthesia.
What is Regional Anaesthesia (RA) or Peripheral Nerve Block (PNB)?
Regional anaesthesia (RA) or peripheral nerve blocks (PNB) involve injecting local anaesthetic drugs near nerves that supply an area of the body to numb the relevant area. RA or PNB may be used alone or alongside the administration of general anaesthesia or sedation. Further information about RA and PNB can be found here.
What are the risks of RA and PNB?
Nerve blocks are very safe, however, there are some common side effects associated with nerve blocks that are usually not serious or long-lasting, although rarely damage can be caused. The risks vary between the type of RA and PNB performed, and these will be explained to you by your anaesthetist. Further information on the risks of nerve damage can be found here. Occasionally the nerve block may not fully work, either due to technical difficulties or because the operation takes longer than expected and it begins to wear off. If this happens, the local anaesthesia drug can be topped up, or in rare cases, you may be given a general anaesthetic to complete the procedure.
Where can I get more information?
More information regarding general anaesthesia can be found here.
Information specifically relating to anaesthesia for heart surgery can be found here.
Watch this University Hospital Southampton video on what to expect during heart surgery:
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