The document discusses pain relief in labor, detailing the causes of labor pain, including ischaemia of the uterine muscle and stretching of perineal tissue. It outlines various pain relief methods, both pharmacological (like opioids and epidurals) and non-pharmacological (like education and relaxation techniques). The document also highlights the administration procedures, contraindications, and potential complications associated with these analgesic options.

1. Pain relief in labour
Amila Weerasinghe
&
Channa Gunasekara
of
Faculty of Medical Sciences,
University of Sri Jayewardenepura,
Sri Lanka.
2014/09/8

2. What are we going to talk ?
How does pain occur?
Pain is caused by…
Methods of pain relief

3. How does pain occur ?
 1st Stage is due to ischaemia of the
uterine muscle caused by
uterine contraction resulting in
obstruction of its own blood
supply. This result in accumilation
of pain metabolites.
 2nd Stage stretching of perineal tissue by
advancing presenting part of the
fetus.

4. Pain is caused by,
Unpleasant feeling to the mother
Maternal exhaustion – maternal acidosis fetal acidosis
Catecholamine release
Maternal sympathetic over activity
HR, BP, Coronary blood flow
Uterine blood flow & fetal hypoxia

5. Methods of pain relief
Methods
Non pharmacological Pharmacological
Opioids
Inhalational
Epidural
Spinal

6. Non pharmacological
 Educate on the process of labour & pain relief
methods.
 Relaxation
 Breathing exercise
 massaging

7. Pharmacological
Opioids
• Pethidine 75mg IM 4-6 hourly (1mg/kg)
• With(antiemetic) promethazine 25mg IM
• S/E nausea
vomiting
delayed gastric emptying
respiratory depress(reversed by Naloxon)
maternal drowsiness & sedation
• Morphine also can be used, but S/E more
(Respiratory depress)

8. Inhalational analgesia
• N2O in the form of Entonox
Quick onset(1-2min), short duration of effect (2-
8min ) start inhaling at the onset of a contraction
• Not suitable for prolong use of early labour
because hyperventilation can cause
hypocapnoea, dizziness & ultimately fetal hypoxia

9. Epidural analgesia
• Epidural catheter inserted at the level of L2-L3
L3-L4 or L4-L5 interspace & to the epidural space.
• Catheter is aspirated to check the position
• Test dose given to confirm the catheter position
small volume of diluted local anaesthetic (10-15ml)
• After 5mins loading dose of mixture of 0.1%
Bupivacaine with fentanyl 12mcg/ml is given
• Prepare ephedrine for IV injection(30mg diluted in
9mg of saline or water)
• Infusion of epidural solution 6-12ml/hr

10. Important…
• Secure IV access
• Establishment/after each bolus measure BP every 5min
for 15min,provide continuous EFM for 30 min
• Every hour; check level of sensory block.
• Continue until completion of the 3rd stage & any
perineal repair.
• Birth should take place within 4hours.

11. Contraindications
• Coagulation disorders
• Local or systemic sepsis
• Hypovolamia
• Insufficient no.of trained staff

12. Complications
• Accidental dural puncture-leak of CSF causing spinal
headache
• Accidental total spinal anaesthesia -severe
hypotension, respiratory failure, unconsciousness &
death
• Drug toxicity occur with
accidental placement of catheter
within a blood vessel
• Bladder dysfunction
• Short term respiratory distress in
baby

13. Spinal Anaesthesia
• A fine gauge atraumatic spinal needle is inserted
in to the subarachnoid space
• Small volume of local
anaesthetic is injected, after
which the spinal needle is
withdrawn
• Not used for routine analgesia
in labour
• Combined spinal- epidural analgesia?