Neuraxial Anaesthesia
What Is Neuraxial Anaesthesia?
Neuraxial anaesthesia is a local anaesthetic, often combined with a small dose of opioid, that is injected into the fluid surrounding the spinal cord in the lower back. This temporarily blocks pain and movement in the lower half of the body while you remain awake and aware. It is a safe and commonly used technique for caesarean sections, gynaecological, urological, and lower limb surgeries.
When Is Neuraxial Anaesthesia Used?
Neuraxial anaesthesia is often recommended for:
- Caesarean sections and obstetric procedures
- Urological, gynaecological, and lower limb surgeries
- Patients who wish to remain awake during surgery
- Patients who are unsuitable for general anaesthesia
- It may also be combined with general anaesthesia to provide excellent intraoperative and postoperative pain relief during major abdominal or pelvic procedures.
How Is Neuraxial Anaesthesia Delivered?
Neuraxial anaesthesia is administered and monitored by an anaesthesiologist:
- Positioning
You will be asked to sit up or lie on your side to allow access to your lower spine. - Skin Preparation
Your lower back will be cleaned with an antiseptic, and a small dose of local anaesthetic will numb the skin. - Injection
A fine needle is inserted into the subarachnoid space in your lower back. Anaesthetic medication is injected to block nerve signals from the lower body. - Onset and Monitoring
You may feel warmth, tingling, or heaviness in the legs as the anaesthetic takes effect — usually within 10 to 15 minutes. Throughout the procedure, your blood pressure, heart rate, and oxygen levels will be continuously monitored. - Surgery Begins
Surgery will only commence once your anaesthesiologist confirms that the block is working effectively. You may feel pressure or movement but should not feel pain.
What to Expect Afterwards
Following your surgery, you will be transferred to a recovery area for further monitoring while the effects of the spinal anaesthetic wear off. You may temporarily have:
- Numbness or weakness in the legs
- Difficulty passing urine (a catheter is often used during surgery)
- Shivering or mild nausea
Most patients regain full sensation and mobility within a few hours. Your anaesthesiologist will ensure that your postoperative pain is well managed using appropriate medication.
Risks and Complications
Common Risks:
- Low blood pressure
- Nausea or vomiting
- Shivering
- Urinary retention
- Anxiety or discomfort from being awake during surgery
Uncommon or Rare Risks:
- Post-dural puncture headache (worse when sitting or standing)
- Bleeding near the spinal cord (especially if on blood thinners)
- Infection at the injection site or in the spinal fluid (meningitis)
- Incomplete or patchy anaesthesia requiring additional intervention
- Allergic reaction to local anaesthetic
- Temporary or, very rarely, permanent nerve injury
Fasting Guidelines
To ensure your safety under neuraxial anaesthesia, you will need to fast before surgery.
- No Solid Food: Stop eating at least 6 hours before your scheduled procedure.
- Clear Fluids Allowed: You may drink water, clear apple juice, or weak black tea up to 2 hours before surgery. Avoid milk, formula, or juice with pulp.
- Babies and Infants: Fasting instructions vary by age and type of feeding. Please follow the specific instructions provided by your anaesthesiologist.
Medical History and Medications
Before your procedure, your anaesthesiologist will meet with you to:
- Review your medical history and current health status
- Go over your current medications
- Perform a focused examination and discuss the anaesthetic plan with you
Please bring a complete list of medications, including:
- Blood thinners (e.g., Aspirin, Warfarin, Clopidogrel)
- Herbal or homoeopathic supplements (ideally stop 2 weeks before surgery)
- Any recreational substances, smoking habits, or alcohol intake
Pregnancy and Breastfeeding
Let your anaesthesiologist know if you are pregnant, trying to conceive, or breastfeeding, as this may influence anaesthetic choices.