1. Dr. Ramilaben Chaudhary 2nd year resident
Labour Analgesia
Dr. Ramilaben Chaudhary
2nd year resident

2. History
Pain during pregnancy is a physiological phenomenon but one must know that once it exceeds a certain intensity and duration does produce harmful effects both on mother and fetus and thence some form of analgesia must be offered to all parturient.

3. Cont….
In1853, Dr John gave first obstetric analgesia to Queen Victoria who delivered Prince Leopold under the effect of chloroform.

4. Nerve Supply Uterus and cervix -Sensory pathway ran by way :
Uterus and cervical ganglia (Frankenhauser) ,inferior and superior hypogastric plexus. 
Posterior roots of 11th and 12th thoracic nerves (T11 & T12) and sometimes T10 and L1.

5. Motor pathway run by Starts in 10,11 and 12th thoracic vertebra 
Aortic,hypogestric & uterine plexuses
Terminate in uterus

6. Vulva, Vagina and perineum
Afferent fibers carrying sensations from birth canal,perineum and vulva.
Afferent fibers of posterior roots of S2, S3 and S4.
Main motor supply via Pudendal nerve

7. Cause of pain -thinning of lower uterine segment
First stage:
Due to - uterine contractions
-thinning of lower uterine segment
- dilatation of cervix

8. Second stage - Stretching of vulva, vagina and perineum. Due to
-Uterine contractions
- Stretching of vulva, vagina and perineum.

9. Third stage - Uterine contraction Due to
-Passage of placenta through cervix
- Uterine contraction

10. Causes of pain Myometrial hypoxia Stretching of cervix
Pressure on nerve ganglia adjacent to cervix
Pressure on bladder, urethra and rectum
Traction on tubes, ovaries and peritoneum
Traction on supporting ligament
Distension of muscles of pelvic floor

11. Ideal prerequisites For the mother: - Relief of pain
- Freedom from fear of vaginal delivery
- Safe and painless delivery
-Efficiency of contractions not decreased
-Pt cooperation is maintained
- Health of mother is not in danger

12. For the infant:
-Should not cause neonatal depression
-Should not cause fetal bradycardia
For the obstetrician:
-Deliberal management of labour
-Optimum condition at delivery

13. Methods of pain relief
Non pharmacological
Pharmacological

14. Non pharmacological Natural child birth -Emotional support
-Hot and cold compresses
-Vertical position

15. Conti…. Acupuncture -Transcutaneous electrical nerve stimulation
-Psycho prophylaxis

16. TENS
Intermittently pulsed electrical current to the back over the lower thoracic and upper spine 
sensory fibres are stimulated & synapse with interneurons in substantia gelatinosa.
So inhibit the release of neurotransmitter
it shortens the overall duration of labour & give great satisfaction to mother.

17. Cont...
Touch and massage
-Hydrotherapy
-Biofeedback
-Hypnosis

18. Pharmacological methods
Systemic drugs:
-Opiates
-Benzodiazepines
-Barbiturates
-Ketamine
-Phenothiazines
-NSAIDS

19. Cont…... Peripheral nerve blockade -Paracervical -Local infiltration
-Pudendal

20. Cont…. Central nervous blockade -Spinal -Lumber epidural
-caudal epidural
-combined spinal and epidural

21. Inhalational agents
Nitrous oxide
Halothane
Isoflurane

22. During first stage of labour
Objectives:
-Pain relief
-Maintaining mother’s cooperation
-No or with interference in progress of labour

23. Systemic medications
Paracervical block
Epidural block

24. Systemic medications They cross the placenta They may be
-Narcotic medications
-Amnesics
-Sedative tranquilizers

25. Narcotic medications Used to alleviate pain Pethidine can be used.
Dose:50-100mg IM
25-50MG IV
Peak analgesia:IM mins
IV 5-10 mins
Duration: 3-4 hrs

26. Side effects Dose dependant neonatal depression
Decreased beat to beat variability in FHS
Decreased Apgar score
Poor neonatal neurobehavioral score

27. Narcotics effects in fetus can be antagonized with Naloxane 5-10 mg/kg

28. Amnesics Hyoscine is used 0.2 to 0.6mg intramuscularly with analgesia
Effect on maternal behavior is unpredictable e.g. Excitement to Delirium
S/E include dry mouth,fetal Tachycardia

29. Sedative Tranquilizers
Barbiturates:Phenobarbital & secobarbital have been tried but causes fetal respiratory depression with repeated doses.
Phenothiazines:Chlorpromazine,prochlorperazine and promethazine.Desirable effects are Sedation,antiemesis & lack of fetal resp depression.

30. Benzodiazepam Used as sedatives.
Reduce anxiety,promote sleep in early labour & decreased narcotic requirements without prolonging labour.
Diazepam:Crosses placenta immediately
Dose:<30mg
S/E Hypotonia,hypothermia,lethargy and resp.depression in baby

31. Paracervical block Effective method Easily performed
Can be given by Obstetrician

32. Technique Transvaginaly During active phase
20 gauge needle cm long
Into posterolateral Fornices at 3& 9 o’clock position
Effectiveness for 1 hour.

33. Complications Maternal: -Paraesthesia in limbs - IV injection
-Hypotension
-Hematoma
Fetal: % bradycardia
-4%Tachycardia
-2% mixed pattern

34. Pain relief during 2nd stage
Inhalational analgesia
Inhalational anesthesia
Intravenous anesthesia
Regional anesthesia: -epidural
- spinal
-caudal
-Pudendal

35. Inhalational analgesia & anesthesia
Generally reserved for situations where rapid deliveries are required like fetal distress, intrauterine manipulations

36. Nitrous oxide Relatively insoluble in blood
Induction & recovery is fast
effective analgesia during contractions
generally nontoxic
given as Entonox :50:50 mixture in oxygen
so decreased chances of maternal hypoxemia

37. Halothane & Isoflurane
Initial analgesia
Anesthesia follows with higher dosage
BP decreased in a dose dependent fashion
decreased intensity of uterine contraction

38. Intravenous anesthesia
For rapid induction of GA
Agents are Thiopentone,
Ketamine & Propofol
used as inducing agents followed by Inhalational anesthesia for maintenance.

39. Cont….. Thiopentone: <4mg/kg
Ketamine: 0.25mg/kg and infusion rate of 0.5 to 1 microgram/kg/min
-lower doses it is safe and effective
-Higher doses:-maternal apnea
-Laryngospasm
-hypertension &  ut tone.

40. Cont…. Contraindications of Katamine -Pre eclampsia -Eclampsia
-Hypertension
-Psychiatric disease
-Epilepsy

41. Regional Anesthesia Epidural block Spinal block Caudal block
Pudendal block
Local infiltration

42. Advantages of regional anesthesia
Complete relief of pain is possible so decreased degree of hyperventilation and improve Utero placental perfusion.
Nearly eliminate psychological and emotional reaction to severe pain.

43. Effective pain relief changes incoordinate uterine contraction to co ordinate one and improve the placental circulation.
Allow parturient to be awake and participate in in labor.

44. Disadvantages
Increased incidence of Occiput posterior or Occiput transverse position if premature perineal relaxation is produced.
Complications like maternal Hypotension,total spinal & local anesthetic toxicity is possible.
Urge to bear down is decreased.

45. Epidural Anesthesia Technique: During active phase of labour
-pt on side or sits up
-Needle in 2nd & 3rd lumbar interspace
-Catheter is inserted
-Drug is injected
-Relief of pain in 5-10mins & max. effect in mins.

46. Contraindications Allergy to the drug Coagulopathy
Skin infection at site
Significant hemorrhage
Supine Hypotension syndrome
Significant cardiopulmonary ds.
Ds of CNS or PNS

47. Limitations Autonomic blockade Hypotension
Post dural puncture headache.
Missed segment
High or total spinal blockade.

48. Commonly used drugs Bupivacaine:Most commonly used.
-Concentration ranging from0.05% to 0.5% .
-Maximum dose:2mg/kg every 4hrly
-Duration of action:2-3 hrs
-S/E: cardiotoxicity if given IV.

49. Cont... Lignocaine:Used as 1-2% solutions
-Toxic dose is 3mg/kg without adrenaline & 6-7mg/kg with adrenaline
-Effective concentration are % for labour and vaginal delivery
S/E: At higher conce. Compromised neonatal neurobehavioral function

50. Caudal block
Performed by injecting into caudal space through sacral hiatus .
Only after active phase.
For block below T10
Damage may occur to fetal head.
May paralyse perineal muscles

51. Spinal block Advantages: -Excellent anesthesia
-Easier to administer than epidural
-Useful for difficult deliveries

52. Disadvantages Post spinal dural headache Bladder dysfunction
Parasthesia in lower limb
Can not be used in early labour
Increased incidence of operative deliveries

53. Double catheter
One catheter in lumbar epidural space and another in caudal space.
Combine epidural & extradural analgesia is more popular
Now a days very popular

54. Pudendal Block Time of administration; Primi: Full dilatation
Multi: 7-8cm dilatation
Gives perineal analgesia & relaxation

55. Indications Spontaneous vaginal delivery Low forceps Breech deliveries
Episiotomies
Repair of lacerations

56. Types
Percutaneous Trans perineal
Trans vaginal

57. Advantages: -Simple
-No systemic or fetal effects
-Mother awake
-No effects on ut contraction
Disadvantages:-Does not relieve pain but gives perineal analgesia & relaxation
-Perineal & Vulval infiltration needed.
-Needle breaks & inj. Into vessel

58. Local Anesthesia For incision and repairs of episiotomy
Agent used is Xylocaine 1%
S/E:Trauma and inj of LA into fetal scalp .

59. Anesthesia for LSCS
Local
General
Spinal

60. Depends on Indication of CS Prevalence of maternal condition
Presence of complicating obstetric factors
Fetal status
Wishes of patients

61. Multiple pregnancy Epidural for labour ,vaginal delivery and CS
GA may preferred
Anteparterm hemorrhage
General Anesthesia

62. Preeclampsia & eclampsia
Epidural analgesia if no contraindications of that.
GA may be used
Diabetes malitus
Epidural blockage for labour and delivery
GA or regional for CS

63. Cardiac disease For Acynotic with mild MS epidural is preferred .
For pts on anticoagulant:sedatives + Paracervical block.

64. PROGRAMMED LABOUR inclusion criteria. age-18-35yrs. maturity-37-41wks
PROGRAMMED LABOUR inclusion criteria *age-18-35yrs *maturity-37-41wks *clinically no CPD *no medical or obstetric risk factors *no fetal distress With experience , high risk cases can be included

65. Entry criteria. Cx dilatation->3cm $ >50% effaced
Entry criteria *Cx dilatation->3cm $ >50% effaced *fetal head should be engaged *show or amniotomy *Ut. Contraction ->3/10 min.& last for sec.

66. Protocol
*Amniotomy
*FHS monitoring
*Optimizing pains by prostaglandins or oxytocins
*Optimizing pain relief facilitated by – 6.0 mg pentazocin & 2,0 mg diazepam diluted in 10 ml DW & give IV
*Tramadol -1.0mg/kg wt IM
*Inj. Drotin 1amp. Or Inj.Epidocin 1amp.
*at 7-8 cm , if required , inj. Ketamine 0.5mg/kg wt. & then SOS ½ of the initial dose at ½ hrly till delievary

67. Thank you