Pain relief in labour

Question 1

Types of pain relief in labor

Answer 1

Narcotic analgesia:
- Morphine
- Remifentani

Inhalation analgesia:
- Entonox (mixture of nitrous oxide and oxygen

Non-pharmacological methods

Regional analgesia:

• Epidural analgesia: bupivacaine
• Other forms of regional anesthesia

Question 2

Narcotic analgesia

Answer 2

Morphine is the most commonly used now.

§ Side effects of all opiates are nausea and vomiting in mother and respiratory depression in baby.

§ Opiates are often administered with anti-emetics to reduce nausea.

§ Remifentanil is an ultra-short-acting better than pethidine with less neonatal respiratory effects.

§ Mostly narcotic analgesia is used when mother is unsuitable for regional analgesia!

Question 3

Inhalation analgesia

Answer 3

Used in the early labour until the mother switches to stronger analgesia. Best for short-term pain.

§ Widely used agents: Entonox (mixture of nitrous oxide and oxygen) is inhaled as contraction starts.

§ Nitrous oxide causes bone marrow and neurological changes, and decreases fertility.

Question 4

Non-pharmacological methods

Answer 4

Trans-cutaneous electrical nerve stimulation (TENS) is a common method.

§ Involves placement of 2 TENS electrodes pairs on the vertebral column at level of T10-L1 and S2-S4.

§ Effective in early labour and inadequate at late labour.

§ Others: acupuncture, subcutaneous sterile water injections, massage and relaxation techniques.

Question 5

Epidural analgesia

Answer 5

is the most effective and widely used.

§ Does not interfere with uterine contractility, but reduces desire to bear down in 2nd labour stage.

§ A fine catheter is introduced into epidural space L3-L4 with bupivacaine is injected.

§ Addition of opioid to local anesthetic reduces dose requirement of bupivacaine, thus sparing the motor
fibers of the lower limbs and reducing the classic complications of hypotension and abnormal FHR.

§ Complications of epidural analgesia includes hypotension (avoid by low-dose opioids), accidental dural
puncture and post-dural headache (treat by epidural blood patch).

§ Also, coagulopathy, local or systemic infection, and uncorrected hypovolemia may be involved!

§ Oxytocin to induce labour is contradicted with epidural analgesia

Question 6

Other forms of regional anesthesia

Answer 6

All replaced by epidural analgesia due to safety & effectiveness.

§ Spinal anesthesia used as single-shot procedure.

§ Paracervical blockade involves infiltration of local anesthetic agents into paracervical tissues.

Higher greater effects on fetus as it may enter vessels.

§ Pudendal nerve blockade as it leaves pudendal canal and hemorrhoidal nerve.

§ Infiltration directly into perineal tissues over episiotomy site is used for the repair perineal wound.

Toxic symptoms include cardiac arrhythmias and convulsions may result specially with larger dose.