Pain Relief in Labour

Question 1

Antenatal

Answer 1

Education regarding what to expect may help reduce fear, and sense of loss of control; Trusted companion present throughout reduces need

Question 2

Types of Pain Relief

Answer 2

• Entonox (50:50 Nitrous Oxide/Oxygen) – Self-administered, Quick onset, Short half-life
• Narcotic agents (E.g. Pethidine, Diamorphine, Meptazinol) can lead to Neonatal Respiratory
Depression if taken too near to delivery; Might require Naloxone for reversal
• Patient Controlled Analgesia – Remifentanil (Does not cross placenta, Rapidly metabolised)
• Pudendal Nerve Block – For Operative Vaginal Delivery (Lidocaine injected 1 – 2cm medially,
and below Ischial spines transvaginal with Pudendal needle
• Local Perineal Infiltration before performing Episiotomy, or for repairs

Question 3

Epidural Space

Answer 3

• Epidural Space between Dura and Vertebral
Canal; Past Ligamentum Flavum and Anterior
Surface of Laminae, and before Posterior
Longitudinal Ligament; L3/4 Interspace usually
o Contains Spinal Nerve Roots, Spinal Arteries and Epidural Veins; Distance
of about 4 – 5cm; Epidural Anaesthesia
targets the Lumbar region

Question 4

Epidural Anaesthesia

Answer 4

Needle injected by Loss-of-resistance technique usually with NaCl; Once in Epidural space, Catheter threaded in
and Needle withdrawn
• Provides Effective Analgesia, reduced Maternal
Stress response; Can be topped up for
Operative Delivery or other complications;
Also, can provide Post-Operative Analgesia and
used in BP control for Pre-Eclampsia

Question 5

Side Effects of Epidural

Answer 5

Hypotension, Decreased Mobility, Tenderness over injection site can occur

Question 6

Complications of Epidural

Answer 6

include Dural Puncture (leading to headache that worsens on standing or sitting), Respiratory
Depression if migration into Subarachnoid space (Spinal Anaesthesia), Abscess, Haematoma or nerve/cord damage

Question 7

Contraindications to Epidural

Answer 7

Sepsis, Site Infection, Coagulopathy, Raised ICP, Haemorrhage, Cardiovascular and
Haemodynamic Instability, Allergy to LA agents, Fixed CO States (E.g. Severe AS, CM

Question 8

Anaesthesia for Caesarean Section

Answer 8

• Spinal Anaesthesia – Accounts for majority of CS performed in UK; Fasting and Antacid precautions ideally for potential conversion to GA
o IV access essential to counteract Hypotension (Autonomic Blockade)
• Epidural, Combined Spinal Epidural (CSE), General Anaesthesia