Patient Information Sheet
LOWER LIMB SURGERY – REGIONAL ANAESTHESIA (LOWER LIMB BLOCK) AND GENERAL ANAESTHESIA / CENTRAL NEURAXIAL BLOCKADE
On the day of surgery
You will report to either the Day Surgery or the Same Day Admissions unit as instructed. After registration, you will be asked to change into the operating theatre (OT) gown and see a doctor before going into the OT reception area.
Depending on your procedure, you may be offered the option of having a Regional Anaesthesia procedure done for intra-operative and post-operative pain relief, before you are brought into the OT for your surgery. Once in the OT, you will either undergo General Anaesthesia and fall into a ‘deep’ sleep during the surgery; or receive a Central Neuraxial Block to numb the lower half of your body before surgery starts, and be awake or sedated during the surgery.
General anaesthesia (GA)
- General anaesthesia is a state of controlled unconsciousness during which you will feel nothing. It is almost like being in a ‘deep’ sleep.
- Anaesthetic drugs will be injected into a soft plastic tube inserted into a vein in your hand. This is to induce the state of ‘deep’ sleep.
- These drugs stop your brain from responding to sensory messages travelling from the nerves in your body.
- You will be unaware of your surroundings, the surgery or pain.
- You will be asleep for the entire duration of the surgery and woken up only after the surgery is completed.
- You will have no memory of the procedure.
- Your anaesthetist and anaesthetic team will be with you during the surgery.
Common risks associated with GA
This will affect 1 in 10 to 1 in 100 patients who undergo surgery with GA.
- Nausea and vomiting – due to the side effects of the anaesthetic drugs and type of surgery.
- Sore throat – due to the presence of the breathing tube used when you are asleep.
- Giddiness, headache or sleepiness – due to the remaining effect of the anaesthetic drugs.
- Aches (e.g. backache), pains– due to your body posture during surgery.
- Experience pain when drugs are injected – due to the side effects of the anaesthetic drugs.
- Bruising and soreness – due to your body posture during surgery and side effects of the anaesthetic drugs.
- Itch - due to the side effects of the anaesthetic drugs.
Uncommon risks associated with GA
This will affect 1 in 10,000 patients who undergo surgery with GA.
- Eye abrasion causing pain and requiring treatment.
- Damage to teeth and dental work, lips or tongue.
- Injury to the skin, eyes, nerve due to prolonged positioning.
Rare risks associated with GA
This will affect 1 in 10,000 to 1 in 100,000 patients who undergo surgery with GA.
- Being aware of activities in the operating room while still under anaesthesia.
- Inherited muscle sensitivity to particular anaesthetic drugs (malignant hyperthermia). This can cause a rapid rise in body temperature, heart rate and breathing with high blood pressure and muscle rigidity.
- Hoarseness of voice due to direct or indirect injury to the vocal cord.
Very rare risks associated with GA
- Allergy to anaesthetic drugs causing wheezing, rash, swelling, low blood pressure, and poor circulation in severe cases.
- Heart attack (AMI - Acute Myocardial Infarction), stroke (CVA - Cerebrovascular Accident) and pneumonia.
- Brain damage or death.
Sedation
- This involves injecting medication through a vein to keep you drowsy and comfortable while you are under regional anaesthesia (RA).
- You may or may not remember the procedure because of the sedation. You may wake up intermittently, but will usually fall back asleep after.
Regional anaesthesia (lower limb nerve blocks)
- This is an injection of local anaesthetic near the nerves in your leg. Part of your leg should be numb and pain-free for up to 24 hours. You will not be able to move it properly during this time.
- This procedure is conducted before your surgery commences. You will either be awake or lightly sedated during the nerve block procedure.
- The injection is administered near the nerve with the aid of an ultrasound to help visualise the nerve.
- Before conducting the nerve block procedure, a smaller needle will be used to inject some local anaesthetic to the area. This will feel like an ant bite.
- This technique can be used on its own or in combination with GA or sedation.
- A successfully working nerve block reduces the surgical pain by causing numbness and weakness over the blocked limb for up to 24 hours.
- There is always a chance that the nerve block might fail. If this happens, you will be given either intravenous or oral painkillers after the surgery.
Common risks associated with RA
This will affect 1 in 10 to 1 in 100 patients who undergo surgery with RA.
- Nausea and vomiting – due to the side effects of the anaesthetic drugs and type of surgery.
- Giddiness, headache or drowsiness – due to the residual effect of the anaesthetic drugs.
- Aches (e.g. backache), pains – due to your body posture during surgery.
Experience pain when drugs are injected – due to the side effects of the anaesthetic drugs.
- Bruising and soreness – due to your body posture during surgery and the side effects of the anaesthetic drugs.
- Itch - due to the side effects of the anaesthetic drugs.
- Shivering.
Very rare risk associated with RA
Seizures or other life threatening events may occur.
Nerve damage associated with RA
The risk of long-term nerve damage caused by a nerve block is difficult to measure precisely. Studies show that it happens between 1 in 700 and 1 in 5,000 blocks.
- There is a risk of nerve damage after any operation regardless if you have had a block. This can be due to the surgery itself, your lying posture or the use of a tourniquet (a tight band around the leg to minimise bleeding). Swelling around the surgical site or a pre-existing medical condition, such as diabetes, may also contribute to nerve damage.
Central neuraxial block (CNB)
- You may be offered a central neuraxial block as a sole technique for surgical anaesthesia or in combination with sedation or GA.
- This technique involves an injection of local anaesthetic drugs at the back of your spine under sterile conditions.
- You will feel numb from the waist down and your legs will feel weak for up to 4-6 hours. This is so that you do not experience surgical pain at the operation site.
How is it performed?
- You will either be awake or lightly sedated for the procedure.
- Your anaesthetic team will help to position you: you will either sit at the edge of the bed with your feet on a low stool or you will lie curled up on your side with your knees tucked up towards your chest.