1. NON-NEURAXIAL TECHNIQUES FOR LABOR ANALGESIA
Moderator: Dr. Girish Sharma
Presented By: Dr. Arvind Sethi

2. INTRODUCTION
labor pain is one of the most intense pain a women can experience.Efforts have been taken for centuries to remove the labor pain, but it has never been easy in the past as it is in the present. While neuraxial analgesia is the gold standard for achieving complete analgesia in labor, many women do not desire such high-tech pain relief. Many women want to ‘Cope with pain of labor ‘ rather than anhilate the pain completely. For many of these women non-neuraxial techniques will suffice.

3. 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
T10 L1 S2 S4

4. The Intensity of Pain in Labor

5. NON-NEURAXIAL LABOR ANALGESIA
Pharmacological Non-Pharmacological
Systemic analgesia
Parenteral
Inhalational
Techniques' alternative to
regional anesthesia
Paracervical block
Pudendal block
Minimal Training/Equipment
Continuous labor support
Touch and massage
Therapeutic use of heat and cold
Hydrotherapy
Vertical position
Specialized Training/Equipment
Intradermal water injections
Transcutaneous Electrical Nerve Stimulation
Acupuncture/Acupressure
Hypnosis

6. Parenteral opioid analgesia
opioid are the most widely used systemic medications for labor analgesia.
Their use does not require specialised equipment or personnel.
Allows the parturient to better tolerate the pain of labor.
Little scientific evidence suggests that one drug is better than other.
Selection of an opioid is based on institutional tradition/personnel preference
Efficacy and incidence of side effects are largely dose dependent rather than drug dependent

7. Analgesia (contd)
Although narcotics provide both analgesia & sedation, their S.E are:
Maternal: Orthostatic hypotension, nausea, vomiting ,delayed gastric emptying,dysphoria,drowsiness,hypoventilation.
Fetal: ↓ beat-to-beat variability of FHR.
Neonatal: respiratory depression , neurobehavioral changes.

8. Systemic opioids for labor analgesia
DRUG
Usual dose
Onset
Duration
Comments
Meperidine
25-50mg IV
50-100mg IM
5-10min IV
40-45min IM
2-3 hrs
Max. neonatal depression 1-4 hrs after the dose
Morphine
2-5mg IV
5-10mg IM
3-5min IV
20-40min IM
3-4 hrs
More neonatal depression than meperidine
Diamorphine
5-7.5mg IV/IM
5-10min IM
90 min
More euphoria, less nausea than morphine
Fentanyl
25-50ùg IV
100úg IM
2-3min IV
10min IM
30-60min
Less neonatal depresion than with meperidine

9. Systemic analgesia contd.
Nalbuphine
10-20mg IV/IM
2-3 min IV/IM
3-6 hrs
Lower neonatal neurobehavioral scores
Butorphanol
1-2mg IV/IM
5-10min IV
10-30min IM
3-4hrs
Ceiling effect on respiratory depression
Meptazinol
100mg IM
15 minIM
2-3 hrs
Less sedation & respiratory depression
Pentazocine
20-40 mg IV/IM
2-3min IV
5-20min IM/SC
Psychomimetic effects possible
Tramadol
50-100mg IV/IM
10 min IV
Less efficacy & more side effects than meperidine

10. Intermittent Bolus Parenteral opioid Analgesia
Given intermitently via s.c ,i.m, i.v route(preferred)
Faster onset of analgesia
Ability to titrate dose to effect

11. MEPERIDINE Most commonly used opioid for labor analgesia
100 mg i.m repeated once after 4 hrs
Onset ;45 min
Readily crosses placenta by passive diffusion & equilibrates b/w maternal and fetal compartments in 6 minutes
Fetal exposure to meperidine is highest b/w 2-3 hrs after maternal administration(more respiratory depression in neonates born within 2-3 hrs)
Causes less respiratory depression in neonate than morphine
Metabolised in liver to normeperidine which crosses the placenta & is also formed as a result of fetal and neonatal metabolism( half life = 60 hrs in neonate)

12. Meperidine contd. Effect on progress of labor is contentious
Some obstetricians say that it may prolong the latent phase of labor, others administer it to shorten the length of first stage in cases of dystocia
Sosa et al. concluded that meperidine does not benefit women & should not be used in labor with dystocia because of adverse neonatal outcome

13. MORPHINE Currently morphine is infrequently prescribed in labor
Significant analgesic but respiratory depressant
Rapidly crosses the placenta and a fetal to maternal plasma conc. ratio of .96 is observed at 5 min.
Elimination half life is longer in neonates than in adults
Crosses BBB more in fetus
Greater plasma clearance, shorter elimination half life, earlier peak metabolite levels occur due to changes in pharmacokinetics during pregnancy

14. Diamorphine A synthetic derivative of morphine
Rapid, effective analgesia with less nausea & vomiting but more euphoria than morphine
Crosses placenta & associated with respiratory depression

15. FENTANYL Synthetic opioid with analgesic potency
100 times that of morphine
800 times that of meperidine
Rapid onset, short duration of action, lack of active metabolite make it attractive for labor analgesia
Average umbilical –to-maternal conc. ratio remains low at 0.31
The researchers found less sedation, vomiting,no adverse effect on APGAR score or fetal acid-base status

16. NALBUPHINE Mixed agonist-antagonist opioid analgesic
Potency and respiratory depression are similar with morphine at equianalgesic dose
Ceiling effect on respiratory depression with increasing dose(max. with 30mg dose)
Mean umbilical vein-t0-maternal conc. ratio is higher with nalbuphine than with meperidine
less nausea, vomiting but more maternal sedation than meperidine

17. BUT0RPHANOL opioid with agonist-antagonist properties
5 times as potent as morphine & 40 times as potent as meperidine
Respiratory depression with
butorphanol , morphine,meperidine
(2mg) = (10mg) (70mg)
(4mg) < (20mg) (140mg)
Butorphanol(1-2mg) when compared with meperidine(40-80mg) for labor analgesia , it has less maternal side effects, better analgesia at 30min and 1 hour with no difference in APGAR score.

18. Butorphanol(cont.)
Butorphanol offers analgesia with some sedation( similar to meperidine+ phenothiazine)
Shorter half life and inactive metabolite.
Favorable neonatal neurobehavioral outcome
A USEFUL AGENT FOR LABOR ANALGESIA

19. MEPTAZINOL
Partial opioid agonist with less sedation, resp. depression, dependence
Neonatal half life =3.4 hrs
Higher APGAR score at 1min
Limitations; Higher Cost & Availability

20. PENTAZOCINE Synthetic opioid , both agonist and weak antagonist
30-60mg equipotent as 10mg morphine
Ceiling effect on respiratory depression occurs at mg
Limitation ;Psycho mimetic effect at higher doses

21. TRAMADOL Atypical, weak synthetic opioid Potency 10% that of morphine
No respiratory depression
More nausea
Analgesia not superior to meperidine

22. PROGRAMMED LABOR (Modern management of labor)
Criteria for selection of cases
Gestational age of weeks
Cervical dilatation ≥ 4cm
Cervical status: bishop score >6
Engaged head & adequate pelvis
No pregnancy induced complication like APH or medical disorders like Heart disease, DM, HTN, Jaundice.

23. Programmed labor(contd.)
Labor is programmed in the following way
When the case is in active phase i.e. os ≥ 4cm
1) LR (500ml) with 2.5U oxytocin started such that contractions ≥3 per 10min lasting for sec.
2) ARM done.
3) 2mg of diazepam (1ml) & 6mg of pentazocine(2ml) diluted with 7ml of normal saline, so that total solution is 10ml. Total 2ml of the solution is given slow iv. Remaining 8ml added to iv fluid post-partum during repair of tear or episiotomy.
4) Inj. drotaverine & tramadol given i.v. and repeated as required.
5) Partographic management of labor is done

24. Active management of labor with oxytocin, amniotomy and spasmolytic and labor analgesia with tramadol,diazepam & pentazocine is safe, convenient and acceptable.
Marked labor analgesia.
There is marked reduction of the total duration of labor.
Marked in LSCS rate.
Minimum side effects on mother.
No effect on of apgar score of fetus

25. PATIENT CONTROLLED ANESTHESIA
Patient-controlled analgesia (PCA) is commonly assumed to imply on-demand, intermittent, IV administration of opioid under patient control (with or without a continuous background infusion).
This technique is based on the use of a sophisticated microprocessor-controlled infusion pump that delivers a pre-programmed dose of opioid when the patient pushes a demand button
Besides i.v., alternative routes for PCA delivery are
s.c., oral,transmucosal,nasal,intrathecal,epidural,transdermal

26. PCA has several modes of administration.
Most common ;
demand dosing (a fixed-size dose is self-administered intermittently)
continuous infusion plus demand dosing (a constant-rate fixed background infusion is supplemented by patient demand dosing)
All modern PCA devices offer both modes.
Less common
1)Infusion demand ( successful demands are administered as an infusion)
2) preprogrammed variable-rate infusion plus demand dosing ( the infusion rate is preprogrammed on an interval clock to vary or turn off altogether by time of day)
3) variable-rate feedback infusion plus demand dosing (microprocessor monitors demands and controls the infusion rate accordingly) .

27. Advantages of PCA Superior pain relief with lower doses of drug
Less risk of maternal respiratory depression
Less placental transfer of drug
Less need for anti-emetic agents
Higher patient satisfaction

28. Limitations
Despite frequent administration, small doses of opioid may not be effective for fluctuating intensity of labor pain
Risk to fetus & neonate remains unclear
Variable doses & lockout intervals have been used
Most appropriate drug, dose ,dosing schedule have not been defined

29. opioid USED FOR PCA DRUG Patient Controlled Dose Lockout interval
Meperidine
10-15mg
8-20min
Nalbuphine
1-3mg
6-10min
Fentanyl
10-25úg
5-12min
Remifentanil
(bolus)
(background infusion with bolus dose)
úg/kg
Infusion rate
0.05úg/kg/min
Bolus;0.25úg/kg
2-3min

30. INHALATIONAL ANALGESIA
PRINCIPLE
An attractive option since pregnancy causes
decreased FRC
increased minute ventilation
Rapid equilibration b/w inspired and alveolar conc.of inhaled agent
Features of inhalational agent that make it suitable for labor analgesia are related to
1) Nature of labor pain: pain is felt sec. after onset of uterine contraction & lasts for sec.
2) Blood gas solubility: low inhalation at onset of contraction results in analgesic blood levels which rapidly falls out at the end of contraction

31. INHALATIONAL ANALGESIA
ENTONOX: NITROUS OXIDE(50%)+ OXYGEN(50%)
Provides partial pain relief during labor as well as at delivery.
50% N2O in O2.(Pre-mixed in a blender)Poynting effect involves dissolution of gaseous O2 bubbled through liquid N2O with vaporization of liquid to form gaseous mixture.
It’s administered with a mask / mouthpiece in a manner such that the parturient remains awake, cooperative & in control of her airway  to prevent pulmonary aspiration of gastric contents.
Does not prolong labor or interfere with uterine contractions but administration > 20 minutes may result in neonatal depression.
Dec. risk of neonatal depression when compared with narcotics.

34. Instruct pt. to inhale deep in b/w the contraction
Inhale 30 sec. before the next anticipated contraction & cease with receding of contraction
In b/w mask may be removed which is held by pt.
Inform that total relief of pain will not occur but gas will provide some relief
IV line, pulse oximetry
Methoxyflourane, Enflurane,Isoflurane do not have any adv. over nitrous oxide

35. SEVOFLURANE MOST COMMONLY USED VOLATILE HALOGENATED AGENT
0.8% sevoflurane is optimal conc. for labor analgesia
Investigators concluded that sevoflurane can provide useful analgesia for labor & is superior to Entonox
Initial studies of intermittent sevoflurane are promising , but larger studies are needed to assess the incidence of maternal compromise

36. Drawover oxford Miniature vapouriser

37. PARACERVICAL BLOCK
Provides satisfactory pain relief during first stage
Goal: to block paracervical(Frankenhauser’s) ganglion which is immediately lateral & posterior to cervicouterine junction
Does not adversely affects labor
provides good analgesia in first stage without the annoying sensory & motor blockade
Does not relieve pain during late first stage& second stage of labor

38. Technique:
Patient in modified lithotomy position(pillow below pt.’s right buttock to correct dextrorotation of uterus
Use a needle guide to define & limit the depth of injection & to reduce the risk of vaginal & fetal injury
Introduce needle & needle guide into left/right lateral vaginal fornix at 4’0’ clock or 8’0’ clock position (with left hand for left and right hand for rt. side.
Needle is advanced through vaginal mucosa and to a depth of 2-3mm
5-10 ml of local anesthetic(without epinephrine) is injected on each side

40. Maternal complications
Vasovagal syncope
Lacerations of vaginal mucosa
Systemic local anesthetic toxicity
Parametrial hematoma
Postpartum neuropathy
Paracervical or subgluteal abscess

41. Fetal Complications
1)Fetal injury from direct injection of LA into fetal scalp(advanced labor>8cm) leading to systemic toxicity
2)Fetal Bradycardia in 15% cases because of
drug induced uterine artery vasoconsriction,CNS depression. myocardial depression
decreased placental perfusion because of uterine hypertonia as a result of post paracervical block causing increase in uterine activity
Manipulation of fetal head,uterus,uterine vessels produce reflex bradycardia

42. PUDENDAL BLOCK
Goal is to block the pudendal nerve distal to its formation by the ant. division of S2-S4 but proximal to its division into branches.
Provide satisfactory anesthesia for vaginal delivery & outlet forceps application
Administered shortly before delivery
Analgesia produced in lower birth canal & perineum provides maternal comfort for low forceps delivery & episiotomy.
Advantages: easy to administer, not a/w maternal hypotension/ fetal distress.
Disadvantage: incomplete analgesia at the time of delivery, since pain of uterine contraction is unaffected

43. Technique Transvaginal—preffered Transperineal
A tubular introducer is placed against vaginal mucosa just beneath the tip of ischial spine
A 15cm ,22G needle is pushed through introducer 1-1.5cm beyond the introducer into the mucosa
1ml of 1% lignocaine is injected into mucosa after aspiration
Sacrospinous ligament is infiltrated with 3ml of lignocaine
3ml is injected into loose areolar tissue behind the sacrospinous ligament
needle is withdrawn into introducer & moved to just above the ischial spine & rest of 10ml is injected into mucosa

45. Pudendal block(cont.)
within 3-4 min successful block is achieved(allows pinching of lower vagina & posterior labia without pain and loss of anal reflex
COMPLICATIONS
Intravascular injection
Hematoma from perforation of blood vessels
Secondary infection at the injection site which may spread to hip joint, gluteal muscles.

46. NON-PHARMACOLOGIC ANALGESIA

47. Continuous Labor Support
Patient’ sense of isolation adversely affects her perception of labor.
A meta-analysis evaluated results from 16 studies that included more than women who were randomly assigned to receive either continuous labor support or usual care .Women who received one-on one support were less likely to use any type of analgesia & were more likely to have short labor, spontaneous vaginal delivery and were better satisfied.

48. Warm compresses on localized areas of body
Touch & Massage
Effleurage, Counter pressure to alleviate back discomfort, light stroking, and merely a reassuring pat.
Therapeutic use of heat & cold
Warm compresses on localized areas of body
Ice packs on low back or perineum to decrease pain perception

49. Hydrotherapy
Simple shower or tub bath or a whirlpool or large tub specially equipped for pregnant women.
Decreases anxiety and pain and increases uterine contraction efficiency

50. Vertical position INCLUDE Sitting, Standing, Walking, Squatting
women reported less pain in vertical positions than in horizontal positions(supine,lateral)
Walking neither enhanced nor impaired active labor & was not harmful to mothers or their infants.

51. Intra-dermal Water Injections
Intra-dermal water injections are used to treat lower back pain which is a common complaint during labor
The afferent nerve fibres that innervate the lower back, enter the spinal cord at T10 through L1 spinal segments.
Technique: approx ml of sterile water is injected intradermally to form a small bleb over each posterior superior iliac spine on both sides & at 3cm below & 1cm medial to each spine(Four injections)

53. the injections themselves are acutely painful for about seconds, but as the injection pain fades. so does the lower back pain.
A simple method of reducing severe low back pain without adverse effects on mother and fetus
cts

54. Transcutaneous Electrical Nerve Stimulation (TENS)
Involves transmission of low-voltage electrical current to surface electrodes placed over lower back in the region of T10-L1
Reduces pain by nociceptive inhibition at a presynaptic level in dorsal horn by limiting central transmission.Electrical stimulation activates low- threshold myelinated nerves.
Afferent inhibition inhibit propogation of nociception along unmyelinated small “c” fibres by blocking impulses to target cells in substantia gelatinosa of the dorsal horn.
TENS also enhances release of endorphins and dynorphins centrally.

55. Acupuncture/Acupressure
Four randomized control trials found that pain score were lower in women randomized assigned to receive acupuncture treatment, as was the rate of use of other modes of analgesia. A shorter duration of the active phase of labor and a reduction in use of oxytocin in acupuncture group was observed.
Hypnosis
Limitations;
Ante partum training sessions are required.
Trained hypnotherapist must be available during labor
Offers no clear benefit

56. Childbirth preparation classes and non- pharmacologic analgesic techniques are not comparable with regional analgesia techniques for relief of labor pains. So whether it is useful for anesthetist to have knowledge of these techniques? Our active participation in the childbirth education classes may help patients receive more accurate information about the risks and benefits of analgesia/anesthesia for labor, vaginal delivery. We can encourage instructors to prepare pt. for the unexpected as “Typical labor” may infact be atypical. Thus patients will perceive anesthetist as an integral part of obstetric team.

57. THANK YOU