Pain Relief in Labour

Question 1

What are the different options of pain relief in labour?

Answer 1

Gas and Air: 50:50 NO:O2 (NO=entenox)

Systemic opiates (diamorphine/pethidine/meptazinol)

Epidural analgesia

Spinal analgesia (usually reserved for CS)

Pudendal nerve block usually reserved for perineal repair/episiotomy

Non pharmacological:

• Warm baths
• Aromatherapy
• TENs machine (transcutaneous electrical nerve stimulation) works by promoting release of endogenous endorphins

Question 2

Describe the pain source during stages 1 and 2 of labour?

Answer 2

Stage 1:
Pain is coming from the myometrial contractions, it is a visceral pain with the sympathetic nn fibres originating from T10-12

Stage 2:
Pain is from the distension of the pelvic floor vagina and perineum.
Pain travels via the sacral nn S2-S4

Question 3

Outline the major difference between epidural and spinal?

Answer 3

Epidural analgesia is where local anaesthetic is injected into the epidural space, aka the space just above the dura.

Spinal analgesia is where local anaesthetic is injected into the subarachnoid space.

(Other difference is that spinal’s last up to 2hrs but epidurals can be topped up)

Question 4

Outline the advantages and disadvantages of epidural analgesia?

Answer 4

Advantages:
Very effective analgesia
Minimal adverse effects on the foetus
Can be topped up if needed
Patient is awake

Disadvantages:
Takes 20-30mins
Prolongs labour (reduces urge to push) and increased risk of assisted delivery or CS

Question 5

What are the risks of epidurals?

Answer 5

Risks: More common

• May not work 1 in 8
• Hypotension
• Nausea
• Pruritus
• Urinary retention

Rare:
-Dural headache (develops within 2 days usually, caused by a small puncture in the dura) 1 in 100- 1 in 500

Very Rare:

• Infection—> Epidural abscess
• Temporary (up to 6months) or permanent nn damage.
• Epidural haematoma can lead to nn damage.

Question 6

What are the contraindications for epidurals?

Answer 6

Coagulation disorder
Recent previous infection
Hypovolaemia
Inability to remain still

Question 7

What are the advantages and disadvantages of gas and air?

Answer 7

Advantages:

• Moderately effective
• Easily reversible

Disadvantages:

• Can cause lightheadedness
• Nausea
• Hyperventilation

Question 8

What are the advantages and disadvantages of systemic opiates?

Answer 8

Advantages:

• Moderately effective pain relief >NOS
• Easy and fast administration (IM)

Disadvantages:

• Nausea and Vomiting
• Respiratory depression (can affect foetus)
• Can reduce fetal heart rate variability
• Large amounts needed so can cause over sedation

Naloxone should always be available in case of maternal; or fetal over sedation.

Question 9

What are the indications for a GA in a caesarean section?

Answer 9

Generally should be avoided, may be used in emergencies or in women who have contraindications for spinal/epidural analgesia.

Question 10

What are the advantages and disadvantages of GA in caesarean?

Answer 10

Advantages:

• Rapid administration
• Low incidence of hypotension
• Can be used in hypovolaemic women or in this with a high risk of haemorrhage

Disadvantages:

• Increased risk of aspiration
• Neonatal depression
• Causes uterine relaxation which can increase post part haemorrhage.

Question 11

What are the advantages and disadvantages of a spinal anaesthetic?

Answer 11

Advantages:

• Very effective analgesia
• Easier and faster to perform than an epidural.
• Lower dose required than an epidural
• More reliable than an epidural
• Mother is awake so allows immediate bonding

Disadvantages:

• Hypotension
• Respiratory depression
• Only lasts 2hrs