The document discusses various methods of providing anesthesia and analgesia during labor. It begins by defining anesthesia and analgesia. It then discusses the physiology of pain during the first and second stages of labor. It outlines maternal risk factors for anesthesia and debates whether labor pain requires analgesia. The majority of the document then examines both non-pharmacological and pharmacological methods for pain management, including sedatives, regional techniques like epidural and spinal anesthesia, and inhalation methods. It provides details on procedures, dosages, onset times and complications for each method.

1. ANAESTHESIA AND
ANALGESIA IN LABOR

2. Anesthesia: It is the absence of all sensation,
including pain, touch, temperature, and pressure.
Analgesia: It is the absence of nociceptive stimuli,
with the preservation of motor &touch sensation.

3. 1st stage of labor– mostly visceral
 Visceral pain is produced by distention of the uterus and cervix
and ischemia of the uterine and cervical tissue.
 It is 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.
PHYSIOLOGY OF PAIN IN LABOR

5. MATERNAL RISK FACTORS IN ANAESTHESIA
1. Short stature
2. Short neck
3. Marked obesity
4. Severe pre-eclampsia
5. Bleeding disorders
6. Placenta previa
7. Medical disorders, like cardiac, respiratory and
neurological diseases

6. DOES LABOR PAIN REQUIRE ANALGESIA?

7. SEDATIVES AND ANALGESICS
The following factors are important to control the dose
of sedative and analgesics:
1. Pain threshold
2. Parity
3. Maturity of the fetus

8. LABOR ANALGESIA
1
2
NON-
PHARMACOLOGICAL
METHOD
PHARMACOLOGICAL
METHOD

9. NON- PHARMACOLOGICAL METHOD
1 2 3 4 5

11. PHARMACOLOGICAL METHOD

12. SEDATIVE AND ANALGESIC
1. Pethidine (Meperidine):
● Most commonly used.
● Strong sedative but less
analgesic efficacy.
● Generally used in first
phase of labor.

13. Dose:
● IM (commonly used): -50-100mg (1-2mg/kg body wt.), can be
repeated after 4-6 hrs, if woman has not delivered yet.
● IV: -25 mg every 2 hrs.
Onset of action:
● Within 45 min after IM administration.
● Almost immediate after IV administration.

14. SIDE EFFECTS
● Nausea, vomiting, delayed gastric emptying.
● Cross the placenta and accumulates in fetal tissues.
● Depress the respiration and suckling of newborn when
administered before delivery.
● Ranitidine should be given to inhibit gastric acid production
and metoclopramide for vomiting.

15. 2. Fentanyl:
● Lipid soluble synthetic opioid.
● It has analgesic potency 100 times
that of morphine and 800 times
that of pethidine.
● Less neonatal and maternal effects
and nausea and vomiting than
others.
● Performs better in terms of pain
scores in women in labour.

16. Dose:
IV bolus of 25-50 ug (given slowly over 1-2minutes) every hour.
Onset of action: Rapid within 2-3 minutes with short duration of
action, making it useful for labor analgesia

17. 3. Tramadol: -
● It is a synthetic opioid analgesic.
Potency is 10% of pethidine.
● Not as effective as pethidine.
● Causes no clinically significant
respiratory depression

18. ● Dose: -100 mg IM (1-2mg/kg body wt.)
● Onset of action: -within 10 minutes after administration and
effect lasts for 2-3 hrs.

19. 4. Phenothiazines: -
● Promethazine (Phenergan) is
commonly used in labour in
combination with an opioid.
● Weak antiemetic drug.

20. Side effects: -
 Cause sedation in mother.
 Does not cause major neonatal depression.

21. 5. Butorphanol: -
● It is an opioid, 5 times as potent
as morphine and 40 times as
potent as pethidine.
● It offers analgesia with sedation

22. Dose: -1-2 mg IM.
Side effects: -Produce excessive sedation, so not used frequently
for labor analgesia.

23. 6. Narcotic antagonists:
It is used to reverse the respiratory
depression induced by opioid
narcotics.

24. ● Naloxone is given to mother 0.4mg IV in labour.
● It is given to newborn 10 ug/kg IM or IV and is repeated as
necessary when infant is born with narcotic depression.
● It is given to a newborn of a narcotic addicted mother with
proper ventilation arrangement otherwise withdrawal symptoms
are precipitated.

25. 7. PATIENT CONTROL ANALGESIA
● Intravenous analgesia.
● The woman herself controls the frequency
of administration.
● It provides good pain relief in labor.
● It is used in women who desire continuous
analgesia but where epidural analgesia is
contraindicated.
● Maternal respiration should be closely
monitored.

26. Doses: -
● Fentanyl–20-60 ug every 5-10 minutes
● Remifentanil–25-50 ug every 5-10 minutes

27. 8. Benzodiazepines (Diazepam): -
● It is a sedative
● Well tolerated by the patient
● It does not produce vomiting and
helps in dilatation of cervix.

28. ● However diazepam is avoided in labour.
● May be used in larger doses in the management of pre-
eclampsia.
Dose: -5-10 mg.
Disadvantages: -
 Neonatal hypotonia
 Hypothermia

29. INHALATION METHODS:
Premixed nitrous oxide and oxygen
Nitrous oxide inhalational analgesia is administered as a blend
of 50% nitrous oxide and 50% oxygen.
● Used in: -Second phase (from 8 cm dilation of cervix to
delivery).

30. ● Laboring woman uses a handheld
face mask to self-administer the
anesthetic gas.
● It takes 50 seconds to take effect.
● Woman is instructed on correctly
timing for each inhalation.
● Woman is to take slow and deep
breaths before the contractions
and to stop when the
contractions over.

31. ● The woman should be monitored with pulse oximetry
● It is safe because when the woman becomes drowsy, she will
automatically drop the mask.
● Provides significant degree of pain relief and may be useful in
situation where epidural analgesia is not available.
● Does not cause neonatal respiratory depression or affect
contractility.

32. Side effects:
● Hyperventilation,
● Dizziness,
● Hypocapnia.

33. INFILTRATION ANALGESIA:
Perineal infiltration: -
● For episiotomy-
● Extensively used prior to episiotomy

34.  10 ml syringe, with a fine needle and about
8-10 ml 1% lignocaine hydrochloride
required.
 The perineum on the proposed episiotomy
site is infiltrated in a fan-wise manner
starting from the middle of the fourchette.
 Each time prior to infiltration, aspiration to
exclude blood is mandatory.
 Episiotomy is to be done about 2-5
minutes following infiltration.

35. REGIONAL (Neuraxial) ANESTHESIA
● When complete relief of pain is needed throughout labor,
epidural analgesia is the safest and simplest method.
● It provides sensory as well as various degrees of motor
blockade over a region of the body.
● Trained personnel is required to make use of this method in
normal and abnormal labor.

36. Epidural Analgesia
● It is a central nerve block technique accomplished by injecting a
local anesthetic.
● A lumbar puncture is made between L2 and L3 with the epidural
needle (Tuohy needle).
● For complete analgesia, a block from T10 to the S5
dermatomes is needed. For cesarean delivery, a block from T4 to
S1 is needed. Repeated doses (top ups) of 4-5 mL of 0.5%
bupivacaine or 1% or lignocaine are used to maintain analgesia.

37. Contraindications: -
 Maternal coagulopathy
 Supine hypotension
 Hypovolemia
 Neurological diseases
 Spinal deformity
 Skin infection at injection site

38. PROCEDURE
 A preload 500 ml of IV fluids should be given prior to
administering epidural analgesia.
 Aseptic precautions must be used.
 Epidural block can be performed in the lateral or sitting
position.
 Lumbar spine is palpated and the widest interspace below L3 is
chosen.
 A local anesthetic is used to numb the skin.

39.  A spinal needle is slowly advanced while feeling for resistance.
A sudden loss of resistance is felt as the epidural needle enters
the epidural space. Care is taken not to puncture the dura. An
epidural catheter is threaded through the needle and the
needle is removed.
 The catheter is fixed in place.
 A combination of low conc. Bupivacaine and fentanyl is given
as bolus every 2 hours or as needed to maintain maternal
comfort.

42. Precaution: -
● Blood pressure should be recorded prior to administration of an
epidural. Thereafter it should be checked at 5-15 minutes
intervals.
● Continuous fetal heart rate monitoring should be done since
the epidural may cause maternal hypotension, leading to fetal
heart rate abnormality.

43. Complications: -
 Hypotension
 Nausea and vomiting
 Pain at insertion site, back pain
 Post spinal headache due to leakage of CSF through needle
hole in dura
 Ineffective analgesia
 Injury to nerve, convulsions, pyrexia
 Fetal heart rate abnormality

44. PARACERVICAL NERVE BLOCK
● Relief pain during first stage of labor. It blocks visceral sensory
fibers of lower uterus, cervix and upper vagina.
● It does not affect progression of labor.
● It does not block sensory nerves from perineum, so it is not
effective in 2nd stage of labor.
● It can be given only after a cervical dilatation of 4 cm and may
need to be repeated every 1-2 hrs.
● Not used commonly for pain relief during labor.

45. PROCEDURE:
● Following the usual antiseptic safe guards, a long needle (15
cm or more) is passed into the lateral fornix, at the 3 and 9
o'clock positions.
● Needle is inserted into vaginal mucosa for a depth of 3-5 mm.
● Five to ten ml of 1% lignocaine are injected the procedure is
repeated on the other side.
● This dose is quite sufficient to relieve pain for about an hour or
two, and injections can be given more than once if necessary.

47. Complications:
 Post block fetal bradycardia: -occur within 10 minutes of
injection and usually transient but last as long as 40 minutes.
 Systematic toxicity: -occur after administration and may result in
excessive sedation, generalized convulsions, and cardiovascular
collapse.
 Lower extremity paresthesia

48. Pudendal nerve block
● Safe and simple method of analgesia during delivery.
● It does not relieve the pain of labour but affords perineal
analgesia and relaxation.

49. Indications:
 Outlet forceps delivery
 Assisted breech delivery
 Repair of episiotomy and perineal lacerations.

50. Technique: The pudendal nerve may be blocked by either the
transvaginal or the transperineal route
Transvaginal route:
‣ Transvaginal route is commonly preferred.
‣ A 20 mL syringe, one 15 cm (6") 22 gauge spinal needle and
about 20mL of 1% lignocaine hydrochloride are required.
‣The index and middle fingers of one hand are introduced into
the vagina, the finger tips are placed on the tip of the ischial
spine of one side

51. ● The needle is passed in vagina along the groove of the fingers
and guided to pierce the vaginal wall on the apex of ischial
spine and thereafter push a little to pierce the sacrospinous
ligament just above the ischial spine tip.
● After aspirating to exclude blood, about 10 mL of the
anaesthetic solution is injected.
● The similar procedure is adopted to block the nerve of the
other side by changing the hands.

53. SPINAL ANAESTHESIA
● Spinal anesthesia is achieved by a subarachnoid injection of a
local anesthetic (bupivacaine) and an opioid (fentanyl).
● Spinal anesthesia is not used for labor analgesia because the
effect lasts only for a short time (90-120 min).
● It may be used for short obstetric procedures such as forceps,
vacuum delivery, or manual removal of placenta. It is choice for a
cesarean section.

54. Advantages over epidural analgesia: -
 Short procedure time
 Rapid onset of the block (within 5 minutes)
 High success rate

55. Procedure: -
● A preload of 500-1000 ml of IV fluids is given to prevent
hypotension resulting from sympathetic block from spinal
anesthesia.
● Procedure is done under aseptic precautions.
● Woman can be sitting or lying on her side.
● Woman is instructed to arch her back since flexion of spines
opens the intervertebral spaces. The L3/4, L4/5, or L5/S1
interspace is identified.

56. ● The chosen interspace is infiltrated
with a local anesthetic.
● Spinal needle is inserted in midline.
● Resistance increases as the
ligamentum flavum is entered and when
the dura is encountered, with a sudden
‘give’ as dura is pierced.
● Correct placement of needle is
confirmed by a drop of clear CSF
appearing at the hub of the needle when
the stiletto is removed.

57. Complications: -
 Hypotension
 Nausea and vomiting
 Pruritus
 Post-dural puncture headache

58. COMBINED SPINAL-EPIDURAL ANESTHESIA
● Provides rapid onset of action of spinal and longer duration of
action of an epidural.
● It is not a routinely practical technique.

59. Procedure:
● The needle-through-needle
technique involves the introduction of
a Tuohy needle (epidural needle) into
the epidural space
● Another smaller-gauge needle is
then threaded through this into the
subarachnoid space.
● After injecting drugs into spinal
space, needle is removed and a
catheter is inserted into the epidural
space for additional drug injection.

60. GENERAL ANESTHESIA
● Indications: -
 Cesarean section
 In urgent situation (shoulder dystocia, head entrapment)
 Removal of retained placenta
 Suturing of extensive vaginal or perineal tears after vaginal
delivery.
 Management of acute uterine inversion
 If there is contraindication to regional anesthesia.

61. Advantages:
Rapid onset of uterine relaxation occurs,
which is desirable with management of
uterine inversion, internal/external
cephalic version, or fetal entrapment.

62. Complications:
● Aspiration of gastric contents.
● Failure in intubation and ventilation.
● Nausea, vomiting.
● Sore throat.

63. “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”