Epidural

Question 1

Define epidural

Answer 1

Epidural = local anaesthetic blockade, done by injecting the anaesthetic into the epidural space of the spinal cord

Question 2

Difference btwn epidural and spinal anaesthesia?

Answer 2

• Spinal anaesthesia = injected into cerebrospinal fluid
• Larger dose needed
• Slower onset
• May be performed anywhere along the vertebral column
• Easier to achieve segmental analgesia/anaesthesia
• Indwelling catheter can be placed

Question 3

Indications of epidural

Answer 3

•	Sole anaesthetic
o	Orthopaedics – lower limbs
o	Vascular surgery – lower limbs, amputations
o	Obstetrics – Caesarean 
o	Gynaecology 
o	Urology – prostate and bladder
o	General – lower abdominal (appendectomy, bowel, hernia repair)
•	With spinal anaesthetic
•	With general anaesthetic
o	Paediatric – penile, inguinal hernias, lower limbs 
o	Thoracic – thoracotomy, cardiac bypass
•	Acute analgesia
o	Prolonged post-operative analgesia
	Single shot can provide 6-12 hours of analgesia
o	Labour
•	Chronic pain management
o	Disk herniation/degeneration
o	Radiculopathy
o	Spinal stenosis
o	Sympathetic mediated limb pain
o	Pelvic pain

Question 4

Complications of epidural

Answer 4

•	Analgesia/anaesthesia failure
o	Risk factors: obesity, multiparity, history of previous failure, regular opiate use, cervical dilation > 7cm
•	Accidental dural puncture with headache (PDPH)
o	Epidural space only 3-5mm thick
o	Severe and can last days
o	Worsened by raising head above supine
•	Delayed breastfeeding
•	Catheter misplacement
o	Into a vein
	Can cause seizures, cardiac arrest, and block failure
o	Into the subarachnoid space
	Can cause high block, or a total spinal (goes directly to the brainstem to cause unconsciousness and seizures)
•	High block
•	Neurological injury
•	Abscess formation
•	Haematoma formation
•	Paraplegia
•	Arachnoiditis