A brief info on painless labour.

1. Dr RAHUL VARSHNEY

2. As noted by the ASA and the ACOG,
“There is no other circumstance where it is considered
acceptable for a person to experience severe pain,
amenable to safe intervention, while under a
physician’s care.”

3. Philosophy Of Labour Analgesia
• Unfortunately, labor represents one of the few circumstances in which the
provision of effective analgesia is alleged to interfere with the parturient’s and
obstetrician’s goal (e.g., spontaneous vaginal delivery).
• given the complicated neurohumoral and mechanical processes involved in
childbirth, it would be unreasonable to expect that neuroblockade of the lower half
of the body would not have an effect on this process, whether positive or negative.
• Anesthesia providers should identify those methods of analgesia that provide the
most effective pain relief without unduly increasing the risk for obstetric
intervention.
• Despite these risks, many women opt for neuraxial analgesia because no other
method of labor analgesia provides its benefits (almost complete analgesia), and
the risks are acceptably low.

5. The Physiology of Pain in Labor
 1st stage of labor – mostly visceral
◦ Dilation of the cervix and distention of
the lower uterine segment
◦ Dull, aching and poorly localized
◦ Slow conducting, visceral C fibers, enter
spinal cord at T10 to L1
 2nd stage of labor – mostly somatic
◦ Distention of the pelvic floor, vagina
and perineum
◦ Sharp, severe and well localized
◦ Rapidly conducting A-delta fibers, enter
spinal cord at S2 to S4

6. • Pain during first stage is visceral and is therefore mediated by the T10 through
L1 segments of the spine, whereas during the later part of the first stage and
throughout the second stage and additional somatic component is present
mediated by the S1 through S4 segments of he spine.

7. • The first to use Ether and Chloroform
for pain relief in labour in the United
Kingdom was the eminent Scottish
Obstetrician Sir James Young
Simpson, Professor of Midwifery at
the University of Edinburgh. On
January 19, 1847 he administered
ether to an obstetric patient and thus
began a new era in the effective
management of pain in childbirth.
HISTORY!!!

8. • The first woman anesthetized for childbirth in the United States was Fanny
Longfellow in 1847 for her third child. She was the wife of the American poet
Henry Wadsworth Longfellow who actually administered the ether.
• The second woman who was to become famous was Emma Darwin, the wife of
Charles Darwin the eminent 19th century Naturalist. Emma had chloroform given
to her by her husband for the last 2 of her 8 births. The first time she used
chloroform was in 1847 which was before Queen Victoria (1853) and no doubt it
left an indelible impression upon her so much so that for her last birth she was
screaming ‘Get me the chloroform”.
• The third, who was not only the most famous of them all, but the most influential,
was Queen Victoria who in 1853, undaunted by the clergy and with the strong
encouragement of her husband Prince Albert, convinced her reluctant physicians,
to have chloroform administered to her by Dr. John Snow for her 8th confinement of
Prince Leopold.

9. Regional anesthetic techniques, were
introduced to obstetrics in 1900,
when Oskar Kreis described the use
of spinal anesthesia.

11. Does Labor Pain Need Analgesia?

12. Analgesia for Labor and Delivery
• Always controversial!
• “Birth is a natural process”
• Women should suffer!!
• Concerns for mother’s safety
• Concerns for baby
• Concerns for effects on labor

13. • In a survey of 1000 consecutive women who chose a variety of analgesic techniques
for labor and vaginal delivery (including non-pharmacologic methods,
transcutaneous electrical nerve stimulation, intramuscular meperidine, inhalation
of nitrous oxide, epidural analgesia, and a combination of these techniques), pain
relief and overall satisfaction with the birth experience were greater in patients who
received epidural analgesia.

14. Other Benefits
• Effective epidural analgesia reduces maternal
plasma concentrations of catecholamines.
• Decreased alpha- and beta-adrenergic receptor
stimulation may result in better utero-placental
perfusion and more effective uterine activity.
• Effective epidural analgesia blunts this
“Hyperventilation- Hypoventilation” cycle

15. The ideal labour analgesic technique
• is safe for both the mother and the infant,
• does not interfere with the progress of labor and delivery,
• provides flexibility in response to changing conditions,
• provides consistent pain relief,
• has a long duration of action,
• minimizes undesirable side effects (e.g., motor block), and
• minimizes ongoing demands on the anesthesia provider’s time.

16. Indications
• In 2008 and 2010, respectively, the ACOG and the
ASA reaffirmed an earlier, jointly published opinion
that stated that “in the absence of a medical contraindication,
maternal request is a sufficient medical indication for pain relief during labor.”
• Epidural analgesia may facilitate an atraumatic vaginal breech delivery, the vaginal delivery
of twin infants, and vaginal delivery of a preterm infant.
• Facilitates blood pressure control in pre-eclamptic women.
• Blunts the hemodynamic effects of uterine contractions (e.g., sudden increase in cardiac
preload) and the associated pain response (tachycardia, increased systemic vascular
resistance, hypertension, hyperventilation) in patients with other medical complications
(e.g., mitral stenosis, spinal cord injury, intracranial neurovascular disease)

17. Contraindication
• Patient refusal or inability to cooperate
• Increased intracranial pressure secondary to a mass lesion
• Skin or soft tissue infection at the site of needle placement
• Frank coagulopathy
• Recent pharmacologic anticoagulation*
• Uncorrected maternal hypovolemia (e.g., hemorrhage)
• Inadequate training in or experience with the technique
• Inadequate resources (e.g., staff, equipment) for monitoring and resuscitation

18. Types of Labor
Analgesia
1. Non-pharmacological analgesia
2. Pharmacological
3. Regional Anesthesia/Analgesia

19. Regional Anesthesia/Analgesia
• Epidural analgesia
• Spinal analgesia
• Combined Spinal Epidural (CSE) analgesia
• Continuous Epidural analgesia
• Continuous spinal analgesia
• Paracervical block
• Lumbar sympathetic block
• Pudendal block
• Perineal infiltration

20. Epidural Analgesia

21. Patient
Positioning
• Sitting or lateral??
• There is little evidence that patient
position influences the extent of
neuroblockade during initiation of
epidural analgesia/anaesthesia.

22. Intravenous
Hydration
• ASA Task Force on Obstetric Anesthesia has stated that a fixed volume of
intravenous fluid is not required before neuraxial analgesia is initiated. Severe
hypotension is less likely with the contemporary practice of administering a
dilute solution of local anesthetic for epidural analgesia or an intrathecal
opioid for spinal analgesia.
• Studies of intravenous hydration and spinal anesthesia for cesarean delivery
suggest that there is no advantage to administering the fluid before the
initiation of anesthesia (preload) compared with administering the fluid at the
time of initiation of anesthesia (co-load).
• A balanced electrolyte solution (e.g., lactated Ringer’s solution) without
dextrose is the most commonly used intravenous fluid for bolus
administration.

23. Choice of Drugs
• Local anesthetics were administered to block both the visceral and the somatic
pain of labor.
• Intrathecal opioids effectively relieve the visceral pain of the early first stage of
labor, although they must be combined with a local anesthetic to effectively relieve
the somatic pain of the late first stage and the second stage of labor.
• The addition of an opioid to the local anesthetic also shortens latency.
• Contemporary epidural labor analgesia practice most often incorporates low doses
of a long-acting local anesthetic combined with a lipid-soluble opioid.
• Pain and analgesic requirements vary depending on several factors, including
parity, stage of labor, presence of ruptured membranes, oxytocin augmentation, and
whether the opioid is administered in combination with a local anesthetic.

24. Local Anaesthetics
Bupivacaine
• most commonly used agent for epidural labor analgesia.
• Highly protein bound, limits trans-placental transfer.
• After epidural administration of bupivacaine (without opioid) during labor, the patient
first perceives pain relief within 8 to 10 minutes, but approximately 20 minutes is
required to achieve the peak effect. Duration of analgesia is approximately 90 minutes.
Ropivacaine
Levo bupivacaine
Lidocaine
2-chlorprocaine

25. Opioids
Lipid-Soluble Opioids: Fentanyl and Sufentanil.
• In clinical practice, epidural fentanyl and sufentanil are usually administered with a local
anesthetic for the initiation of analgesia.
• The addition of a lipid-soluble opioid to a local anesthetic for neuraxial labor analgesia
decreases latency, prolongs the duration of analgesia, decreases epidural LA
requirement , decreases motor blockade and improves the quality of analgesia.
• Advantages of a lower total dose of local anesthetic include
1. decreased risk for local anesthetic systemic toxicity,
2. decreased risk for high or total spinal anesthesia,
3. decreased plasma concentrations of local anesthetic in the fetus and neonate, and
4. decreased intensity of motor blockade.

26. Alfentanil
Morphine
Meperidine
Butorphanol
Diamorphine

28. Adjuvants
• Epinephrine
• Clonidine
• Neostigmine

29. Epidural Test Dose
• Purpose is to help identify unintentional cannulation of a vein or the
subarachnoid space.
• Epidural test dose: Placement of an epidural catheter and administration
of a standard lidocaine 45 mg/epinephrine 15 μg.

30. • Combination of a low-dose, long-
acting amide local anaesthetic and a
lipid soluble opioid
• This approach improves safety and
leads to less motor blockade and
greater patient satisfaction.
MAINTENANCE OF
ANALGESIA

31. Administration Techniques
1. Intermittent Bolus
• Analgesia re-established with bolus injection of 8 to 12 ml of LA/Opioid
solution.
• Pain relief is constantly interrupted by regression of analgesia.
• The spread and quality of analgesia may change with repeated lumbar
epidural injections.
2. Continuous infusion
• Prolonged infusion might lead to Significant motor blockade. Therefore dose
requires titration.
• Strict monitoring is required as migration of catheter into subarachnoid,
subdural or intravenous space are likely to go unnoticed.

32. 3. Patient controlled Epidural Analgesia
• Bupivacaine consumption is higher in PCEA with a background infusion than in a pure
PCEA technique without a background infusion.
• A meta-analysis of five studies reported in the ASA Practice Guidelines for Obstetric
Anesthesia concluded that a background infusion provides better analgesia than pure
PCEA without a background infusion.
• There is no evidence that the higher local anesthetic dose associated with a background
infusion increases motor blockade or has adverse effects on obstetric outcome when low-
concentration infusion solutions are used.
4. Timed Intermittent bolus Injection

33. Ambulatory Neuraxial Analgesia
• Applied to any neuraxial analgesic
technique that allows safe
ambulation. It was first coined to
describe low-dose CSE opioid
analgesia because motor function
was maintained and the ability to
walk was not impaired.

34. Side Effects of Neuraxial Analgesia
1. Hypotension
2. Pruritis
3. Nausea and vomiting
4. Fever
5. Shivering
6. Urinary retension
7. Recrudescence of HSV
8. Delayed Gastric emptying

35. 1. Hypotension
• The incidence of hypotension after initiation of neuraxial analgesia during labor
is ≈14%.
• In women undergoing spinal anesthesia for cesarean delivery there is no
difference in the incidence of hypotension when crystalloid is administered as a
rapid bolus prior to the initiation of neuroblockade (preload) compared with
administration concurrently with the initiation of anesthesia (co-load). †
• The hypotension associated with neuraxial analgesia is usually easily treated.
Treatment includes the administration of additional intravenous crystalloid,
placement of the mother in the full lateral and Trendelenburg position, and
administration of an intravenous vasopressor
†Preload or coload for spinal anesthesia for elective Cesarean delivery: a metaanalysis. Can J Anaesth 2010; 57:24-31.

36. 2. Pruritus
• Most common side effect of epidural or
intrathecal opioid administration.
• The incidence and severity of pruritus are
dose dependent for both epidural and
spinal opioid administration. The co-
administration of local anaesthetic
decreases the incidence of pruritus,
whereas the co-administration of
epinephrine may worsen pruritus.
• The most effective treatment is a centrally
acting μ-opioid antagonist (e.g., naloxone
or naltrexone) or a partial agonist-
antagonist such as nalbuphine.

37. 3. Nausea and Vomiting
• Nausea is less common after epidural or intrathecal opioid
administration during labor than after the administration of the
same drugs for post– caesarean delivery analgesia. Norris et al.
noted that women who received epidural or intrathecal opioid
analgesia during labor had an incidence of nausea of only 1.0%
or 2.4%, respectively.
• Metoclopramide, ondansetron and droperidol have been used
prophylactically in women undergoing neuraxial opioid
analgesia.

38. Complications of Neuraxial analgesia
1. Inadequate analgesia
2. Unintentional dural puncture
3. Respiratory Depression
4. Intravascular injection of LA
5. High and Total spinal anesthesia
6. Extensive Motor Blockade
7. Prolonged Blockade
8. Sensory changes
9. Back Pain
10. Pelvic floor injury

39. 1. Inadequate Analgesia
• Successful location of the epidural space is not always possible, and satisfactory
analgesia does not always occur, even when the epidural space has been
identified correctly. Factors such as patient age and weight, the specific
technique, the type of epidural catheter, and the skill of the anesthesia provider
are associated with the rate of failure of neuraxial analgesia.
• The risk for failed anesthesia and the potential need to place a second epidural
catheter should be discussed with the patient during the preanesthetic
evaluation, before placement of the first epidural catheter.
• Three types mainly:
1. Extent of block inadequate.
2. Asymmetric block
3. Breakthrough pain

40. 2. Unintentional Dural Puncture
• Rate of unintentional Dural puncture with an epidural needle or catheter was 1.5%.
• Options:
1. Remove the needle and place an epidural catheter at another interspace;
2. If CSE analgesia was planned, the intrathecal dose may be injected through the
epidural needle before it is removed and re-sited at a different interspace.
3. The Anaesthesia provider may place a catheter in the subarachnoid space and
administer continuous spinal analgesia for labor and delivery.

42. 5. High and Total spinal Anaesthesia
• May occur after the unintentional
and unrecognized injection of local
anesthetic (via a needle or catheter)
into either the subarachnoid or
subdural space.
• Alternatively, the epidural catheter
may migrate into the subarachnoid or
subdural space during the course of
labor and delivery.
• High spinal blockade may result from
an overdose of local anesthetic in the
epidural space.

43. • Extensive neuroblockade may also result from injection of a local anesthetic into
subdural space.
• Subdural injection may be difficult to diagnose because onset is later than that with
an intrathecal injection and more closely resembles that associated with epidural
neuroblockade.

44. Impact on Duration of Labour
• A 2011 meta-analysis of 11 studies found no difference in the duration of the first
stage of labor between women who were randomly assigned to receive epidural
analgesia and those assigned to receive systemic opioid analgesia.
• Analgesia-related prolongation of the first stage of labor, if it occurs, is short, has
not been shown to have adverse maternal or neonatal effects, and is probably of
minimal clinical significance.
First Stage of labour

45. Second Stage of labour
• Meta-analyses of RCTs that compared neuraxial with systemic opioid analgesia
support the clinical observation that effective neuraxial analgesia prolongs the
second stage of labor.
• The mean duration of the second stage was 15 to 20 minutes longer in women
randomly assigned to receive neuraxial analgesia than in women assigned to receive
systemic opioid analgesia.
• It was concluded that the second stage of labor does not need to be terminated based
on duration alone.
• Studies have confirmed that a delay in delivery is not harmful to the infant or mother
provided that
(1) electronic FHR monitoring confirms the absence of non-reassuring fetal status,
(2) the mother is well hydrated and has adequate analgesia, and
(3) there is ongoing progress in the descent of the fetal head.

46. • The ACOG has stated that if progress is being made, the duration of the second
stage alone does not mandate intervention

47. Third stage
• Epidural analgesia was not associated with a prolonged third stage of labor. The
duration of the third stage of labor was shorter in women who received epidural
analgesia and subsequently required manual removal of the placenta.
• The ACOG supports the use of oxytocin for the treatment of dystocia or arrest of
labor in the first or second stage, whether or not the patient is receiving neuraxial
analgesia
• There was no difference in the mode of delivery or duration of labor with or
without ambulation in neuraxial analgesia.
Among other factors . . .

48. Impact on Caesarean Delivery Rate
• The latest meta-analysis covered
outcomes for 8417 women
randomized to receive neuraxial
or no neuraxial/no analgesia
(control) from 27 trials The risk
ratio for caesarean delivery in
women randomly assigned to
receive neuraxial analgesia
compared with those assigned
to the control group was 1.10.
• Almost all studies found no
difference in the rate of
caesarean delivery between
women randomly assigned to
receive either neuraxial or
systemic opioid analgesia

49. Instrumental Vaginal Delivery Rate
• Most systematic reviews have concluded that epidural analgesia is associated with a
higher risk for instrumental vaginal delivery than systemic analgesia.
• In a meta-analysis of studies that compared CSE and epidural analgesia, the
instrumental vaginal delivery rate was lower in the CSE group than in the traditional
“high-dose” epidural analgesia groups (risk ratio 0.80; 95% CI, 0.65 to 0.98), but there
was no difference between “low-dose” epidural and CSE analgesia.
• In a 2011 meta-analysis of 23 studies (n =
7935), the risk ratio for instrumental
vaginal delivery in women randomly
assigned to receive epidural analgesia or
non-epidural/no analgesia was 1.42.

50. Timing of initiation of neuraxial
analgesia
• In a retrospective study of 1917 nulliparous women, the rate of caesarean delivery
was twice as high in women who received neuraxial analgesia at a cervical dilation
less than 4 cm than in those in whom neuraxial analgesia was initiated at a cervical
dilation of 4 cm or more.
• For many years the ACOG suggested that women delay requesting epidural
analgesia “when feasible, until the cervix is dilated to 4 to 5 cm.”

51. Timing of initiation of neuraxial
analgesia
• Later in 2006, subsequent to publication of various studies the ACOG published an
update which has the following statement :
“Neuraxial analgesia techniques are the most effective and least depressant treatments
for labor pain. The American College of Obstetricians and Gynecologists previously
recommended that practitioners delay initiating epidural analgesia in nulliparous
women until the cervical dilation reached 4-5 cm. However, more recent studies have
shown that epidural analgesia does not increase the risks of caesarean delivery. The
choice of analgesic technique, agent, and dosage is based on many factors, including
patient preference, medical status, and contraindications. The fear of unnecessary
caesarean delivery should not influence the method of pain relief that women can
choose during labor.”

52. Conclusion
“The delivery of the infant into the arms of a conscious
and pain-free mother is one of the most exciting and
rewarding moments in medicine.”
Moir DD. Extradural analgesia for caesarean section. Br J Anaesth 1979; 51: 1093.

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