Co-ordinator: Dr Veena AsthanaPresented by: Dr Aslam Aziz Rizvi

LABOUR PAIN & RELIEF

02/12/08

DEFINITION OF LABOURDEFINITION OF LABOUR

LABOUR can be defined as LABOUR can be defined as spontaneous spontaneous painful uterine contractions associated painful uterine contractions associated with the effacement and dilatation of with the effacement and dilatation of the cervix and the descent of the the cervix and the descent of the presenting partpresenting part

DEFINITION OF PAINDEFINITION OF PAIN

IASP defined IASP defined PAINPAIN as: as:

““An unpleasant sensory and An unpleasant sensory and emotional experience associated with emotional experience associated with actual or potential tissue damage or actual or potential tissue damage or described in terms of such damage.”described in terms of such damage.”

Copyright © 2003 American Society of Anesthesiologists. All rights reserved.

STAGES OF LABOURSTAGES OF LABOUR

I. From onset of regular uterine I. From onset of regular uterine contractions to full dilatation of cervix.contractions to full dilatation of cervix.

II. From full cervical dilatation to delivery II. From full cervical dilatation to delivery of the fetus.of the fetus.

III. From delivery of the fetus to delivery III. From delivery of the fetus to delivery of the placenta.of the placenta.

Nerve supply of uterusNerve supply of uterus

Sympathetic:Sympathetic:

1.1. Motor ( T5-T6)Motor ( T5-T6)

2.2. Sensory (T10-T11)Sensory (T10-T11)

ParasympatheticParasympathetic

Pelvic n. (S 2,3,4) end in ganglion of Pelvic n. (S 2,3,4) end in ganglion of frankenhauserfrankenhauser

WHY PAIN OCCURS WHY PAIN OCCURS DURING LABOUR?DURING LABOUR?

FIRST STAGE PAINFIRST STAGE PAIN

Visceral painVisceral pain resulting from: resulting from:

a) Uterine contractions a) Uterine contractions

b) Dilatation of the cervix.b) Dilatation of the cervix.

Initially confined to Initially confined to T11-T12 T11-T12 during latent during latent phase.phase.

Eventually involves Eventually involves T10-L1T10-L1 in active phase. in active phase.

Perception begins with the nociceptive stimuli Perception begins with the nociceptive stimuli arising in the mechanical & chemo receptors in arising in the mechanical & chemo receptors in uterus & cervix→ High threshold uterus & cervix→ High threshold mechanoreceptors d/t intense pr. generated mechanoreceptors d/t intense pr. generated during contraction of uterus.during contraction of uterus.

As the labour progresses→ intensity of labour As the labour progresses→ intensity of labour pain ↑ d/t lowering of stimulation threshold with pain ↑ d/t lowering of stimulation threshold with repeated stimuli.repeated stimuli.

Myocellular injury d/t repeated contractions Myocellular injury d/t repeated contractions releases bradykinin, histamine, serotonin, Ach, releases bradykinin, histamine, serotonin, Ach, K+ ions → chemical nociceptors activated.K+ ions → chemical nociceptors activated.

Sensations are then carried by the Sensations are then carried by the AAδδ & & CC fibres that pass through the inferior, middle & fibres that pass through the inferior, middle & superior hypogastric plexus, the lumbar & superior hypogastric plexus, the lumbar & lower sympathetic chain and end in rami lower sympathetic chain and end in rami communicants assoc. with communicants assoc. with T10-L1T10-L1 spinal spinal nerves.nerves.

Dominantly carried by Dominantly carried by C fibres.C fibres.

Pain is Pain is transmitted slowly, poorly localized transmitted slowly, poorly localized and and primarily in the primarily in the lower abdomen.lower abdomen.

Referred to the lumbosacral area, gluteal Referred to the lumbosacral area, gluteal region & thighs as labour progresses.region & thighs as labour progresses.

Pain intensity increases with Pain intensity increases with progressive cervical dilatation & progressive cervical dilatation & increasing intensity & frequency of increasing intensity & frequency of uterine contractions.uterine contractions.

Nulliparous Nulliparous & those with h/o & those with h/o dysmenorrhoea experience greater dysmenorrhoea experience greater pain during 1pain during 1stst stage. stage.

SECOND STAGE PAIN:

Onset of perineal painOnset of perineal pain at the end of 1 at the end of 1stst stage stage signals beginning of fetal descent and the 2signals beginning of fetal descent and the 2ndnd stage stage of labour.of labour.

Caused by Caused by distension of pelvic structures and distension of pelvic structures and perineum perineum following descent of the presenting part.following descent of the presenting part.

This is This is somaticsomatic pain. pain.

Sensory innervation of the perineum is provided Sensory innervation of the perineum is provided by the pudendal nerve (S2-S4), so pain during this by the pudendal nerve (S2-S4), so pain during this stage involves stage involves T10-S4 T10-S4 dermatomes.dermatomes.

It is It is sharpsharp, , well localizedwell localized and and not referrednot referred.. More rapid descent in More rapid descent in multiparous multiparous women is women is

associated with associated with more intensemore intense pain. pain. Dominantly carried by Dominantly carried by AAδδ fibres. fibres.

Pressure on intrapelvic structures usually Pressure on intrapelvic structures usually involves fibres as high as L2 nerves & as low as involves fibres as high as L2 nerves & as low as S3. This is the reason parturients feel the urge to S3. This is the reason parturients feel the urge to push and come to know that the baby is coming.push and come to know that the baby is coming.

Pain of 1Pain of 1stst stage does not end with the start of stage does not end with the start of 22ndnd stage but stage but is superseded by the pain of the 2is superseded by the pain of the 2ndnd stage.stage.

Copyright © 2003 American Society of Anesthesiologists. All rights reserved.

PHYSIOLOGY OF PAIN IN PHYSIOLOGY OF PAIN IN LABOURLABOUR

Pain during labour provides a noxious and Pain during labour provides a noxious and unpleasant stimulus which may prove unpleasant stimulus which may prove deleterious to the mother and fetus.deleterious to the mother and fetus.

Various physiological effects on different Various physiological effects on different organ systems may vary. They are:organ systems may vary. They are:

A. EFFECTS ON VENTILATION:A. EFFECTS ON VENTILATION:

Labour pain serves as a powerful respiratory Labour pain serves as a powerful respiratory stimulant. This results in :stimulant. This results in :

1.1. ↑ ↑ in TV(40%), MV(50%), RR(15%), PaCO2 in TV(40%), MV(50%), RR(15%), PaCO2 ↓↓by 16-by 16-20mmHg with rise in pH to 7.5-7.6.20mmHg with rise in pH to 7.5-7.6.

Thus respiratory alkalosis occursThus respiratory alkalosis occurs→ ↓ Cerebral → ↓ Cerebral and Uterine BF and Uterine BF & shifts the maternal ODC to the & shifts the maternal ODC to the left. left.

Thus ↓in fetal PaCO2 by 23%.Thus ↓in fetal PaCO2 by 23%.

2. With the onset of relaxation phase, pain no longer 2. With the onset of relaxation phase, pain no longer stimulates respiration. So, the hypocapnia causes a stimulates respiration. So, the hypocapnia causes a transient period of hypoventilation that ↓ maternal transient period of hypoventilation that ↓ maternal PaCO2 by 10-50% .PaCO2 by 10-50% .

Thus inc the gradient favouring transfer of CO2.Thus inc the gradient favouring transfer of CO2.

Opioids may further enhance this depression.Opioids may further enhance this depression.

3. Extreme hypocapnia PaCO2 <20mmHg, can 3. Extreme hypocapnia PaCO2 <20mmHg, can reduce UBF & cause fetal hypoxemia & acidosis.reduce UBF & cause fetal hypoxemia & acidosis.

Double Bohr effectDouble Bohr effect

refers to the situation in the placenta where the Bohr refers to the situation in the placenta where the Bohr effect is effect is operative in both the maternal and foetal operative in both the maternal and foetal circulations.circulations.

The inc in pCO2 in the maternal intervillous sinuses assists The inc in pCO2 in the maternal intervillous sinuses assists oxygen unloading. oxygen unloading.

The decrease in pCO2 on foetal side, assists O2 loading. The decrease in pCO2 on foetal side, assists O2 loading. The Bohr effect facilitates the reciprocal exchange of The Bohr effect facilitates the reciprocal exchange of

oxygen for carbon dioxide.oxygen for carbon dioxide. The double Bohr effect means that the oxygen dissociation The double Bohr effect means that the oxygen dissociation

curves for maternal HbA and foetal HbF move apart (ie in curves for maternal HbA and foetal HbF move apart (ie in opposite directions).opposite directions).

B. NEUROENDOCRINE EFFECTS:B. NEUROENDOCRINE EFFECTS:

1.1. Catecholamine levels ↑ 20-40% d/t Catecholamine levels ↑ 20-40% d/t noxious stimulation.noxious stimulation.

2.2. NorAd levels ↑→↓in Ut BF( 35-70%)NorAd levels ↑→↓in Ut BF( 35-70%)

3.3. > 200% ↑in levels of Adr/ Nor Ad/ > 200% ↑in levels of Adr/ Nor Ad/ CortisolCortisol

4.4. Dopamine, cAMP, ACTH, Lactate & Dopamine, cAMP, ACTH, Lactate & Pyruvate also ↑Pyruvate also ↑

C. CARDIOVASCULAR EFFECTS:C. CARDIOVASCULAR EFFECTS:1. 1. CO ↑ d/t CO ↑ d/t

- extrusion of 250-300ml of blood from the - extrusion of 250-300ml of blood from the uterusuterus

- ↑ed VR from the pelvis & LL.- ↑ed VR from the pelvis & LL.

2. Also ↑ in sympathetic activity provoked by 2. Also ↑ in sympathetic activity provoked by pain, apprehension, anxiety and the physical pain, apprehension, anxiety and the physical effort of labour.effort of labour.

Early 1Early 1stst stage: 15% ↑ in CO stage: 15% ↑ in CO

Late 1Late 1stst stage: 30% stage: 30%

22ndnd stage : 45% stage : 45%

Immediately after delivery: 65-80%Immediately after delivery: 65-80%

During contractions: further 15-20%During contractions: further 15-20%

D. METABOLIC EFFECTS:

1. BMR ↑ 20% 2. FFA & Lactate ↑ (d/t ↑ CA & lipolytic

metabolism)3. O2 consumption ↑4. Progressive maternal metabolic acidosis

occurs (d/t loss of HCO3 from the kidney to compensate pain induced respiratory alkalosis)

E. EFFECTS ON GASTROINTESTINAL &E. EFFECTS ON GASTROINTESTINAL &

URINARY SYS:URINARY SYS:

1.1. ↑↑ed gastric acid secretion ed gastric acid secretion

2.2. Stimulation of release of gastrinStimulation of release of gastrin

3.3. Delay in gastric & urinary bladder emptying (d/t Delay in gastric & urinary bladder emptying (d/t reflex inhibition of gastrointestinal & urinary reflex inhibition of gastrointestinal & urinary motility following anxiety)motility following anxiety)

F. EFFECT ON UTERINE ACTIVITY:

CA levels ↑ (d/t pain & emotional stress)Nor Ad: causes ↑ in Uterine activityAdr & Cortisol: ↓/ in-coordinate uterine

contractions.

G. PSYCHOLOGICAL EFFECTS: Fear, apprehension, anxiety can further

enhance pain perception. Severe pain may also produce significant

post partum emotional reactions.

GOALS FOR PROVIDING GOALS FOR PROVIDING PAIN RELIEFPAIN RELIEF

SafeSafe Satisfactory pain relief for the motherSatisfactory pain relief for the mother No depressant effects on the maternal RS / CVSNo depressant effects on the maternal RS / CVS No depressant effects on the babyNo depressant effects on the baby No unpleasant maternal side effectsNo unpleasant maternal side effects No depressant effects on the progress of labourNo depressant effects on the progress of labour High technical success rateHigh technical success rate

METHODS OF LABOURMETHODS OF LABOUR ANALGESIA ANALGESIA

A. REGIONALA. REGIONAL

B. NON-REGIONAL TECHNIQUESB. NON-REGIONAL TECHNIQUES

1.1. NON-PHARMACOLOGICALNON-PHARMACOLOGICAL

2.2. PHARMACOLOGICALPHARMACOLOGICAL

NON REGIONALNON REGIONAL

NON- PHARMACOLOGICALNON- PHARMACOLOGICAL

1.1. PsychoprophylaxisPsychoprophylaxis

2.2. HypnosisHypnosis

3.3. MassageMassage

4.4. Transcutaneous electrical nerve stimulation Transcutaneous electrical nerve stimulation (TENS)(TENS)

5.5. Relaxation/ Breathing techniquesRelaxation/ Breathing techniques

6.6. Temperature modulation: hot/cold packs, water Temperature modulation: hot/cold packs, water immersionimmersion

7.7. AcupunctureAcupuncture

8.8. Aroma therapy 9. BiofeedbackAroma therapy 9. Biofeedback

Psychoprophylaxis/Prepared childbirthPsychoprophylaxis/Prepared childbirth::

1.1. Grantley Dick-Read methodGrantley Dick-Read method

2.2. Lamaze’s psychoprophylaxisLamaze’s psychoprophylaxis

focuses on teaching the parturient conditioned focuses on teaching the parturient conditioned reflexes to overcome the pain & fear of childbirth.reflexes to overcome the pain & fear of childbirth.

It also uses an education program, human It also uses an education program, human support during labour, breathing techniques, support during labour, breathing techniques, relaxation techniques of voluntary muscles, a relaxation techniques of voluntary muscles, a strong focus on attention and specific activities to strong focus on attention and specific activities to concentrate on, during contractions.concentrate on, during contractions.

Disadvantage:Disadvantage:

Since it relies on heavy breathing exercise→ Since it relies on heavy breathing exercise→ may lead to may lead to hyperventilation & subsequent hyperventilation & subsequent alkalosisalkalosis→ impairment of uterine BF & CBF.→ impairment of uterine BF & CBF.

Hypnosis:Hypnosis: Claimed toClaimed to

a) Reduce pain & requirement for a) Reduce pain & requirement for pharmacological pharmacological

analgesia.analgesia.

b) Shorten labour.b) Shorten labour.

Patient is in a trance, in a state of deep Patient is in a trance, in a state of deep concentration & very receptive to suggestion.concentration & very receptive to suggestion.

Disadvantage:Disadvantage:

1. May lead to post partum psychosis1. May lead to post partum psychosis

2. May deprive the patient of the sense of active 2. May deprive the patient of the sense of active participation during labourparticipation during labour

TENSTENS

Reduces pain by Reduces pain by nociceptive inhibition along nociceptive inhibition along unmyelinated small “c” fibres by blocking impulses unmyelinated small “c” fibres by blocking impulses to target cells at a presynaptic level in the to target cells at a presynaptic level in the substantia gelatinosa of the dorsal hornsubstantia gelatinosa of the dorsal horn. Thus . Thus limiting central transmission.limiting central transmission.

Enhances release of endorphins & dynorphins Enhances release of endorphins & dynorphins centrally. centrally.

Electrodes are placed about 2cm over the T10-L1 Electrodes are placed about 2cm over the T10-L1 dermatomes in 1dermatomes in 1stst stage & S2-S4 in the 2 stage & S2-S4 in the 2ndnd stage. stage.

Conventional TENS has high stimulation Conventional TENS has high stimulation frequency (40-150 Hz) and low intensity. Current frequency (40-150 Hz) and low intensity. Current set b/w 10-30 mA.set b/w 10-30 mA.

The pulse duration is short (up to 50 μs).The pulse duration is short (up to 50 μs). The onset of analgesia is immediate. Pain relief The onset of analgesia is immediate. Pain relief

lasts while the stimulus is turned on, but abates lasts while the stimulus is turned on, but abates when the stimulation stops.when the stimulation stops.

Women can alter the amount of current supplied Women can alter the amount of current supplied to the electrodes, thus providing some degree of to the electrodes, thus providing some degree of control.control.

However, no evidence that TENS provides more However, no evidence that TENS provides more analgesia than placeboanalgesia than placebo..

AcupunctureAcupuncture

1.1. Mediated through release of endorphins or Mediated through release of endorphins or serotoninserotonin

2.2. Significantly reduces length of birthSignificantly reduces length of birth

3.3. Reduced requirement of epidural analgesiaReduced requirement of epidural analgesia

4.4. Incomplete, unpredictable & inconsistentIncomplete, unpredictable & inconsistent

PHARMACOLOGICAL METHODSPHARMACOLOGICAL METHODS

INHALATIONAL ANALGESIAINHALATIONAL ANALGESIA

Adm of subanesthetic conc. of inhaled Adm of subanesthetic conc. of inhaled anesthetics to relieve painanesthetics to relieve pain

ENTONOXENTONOX (50% Nitrous Oxide in Oxygen) (50% Nitrous Oxide in Oxygen)

1.1. Used as a sole analgesic & adjuvant to systemic & Used as a sole analgesic & adjuvant to systemic & regional techregional tech

2.2. Provides analgesia within Provides analgesia within 20-30sec20-30sec of inhalation, of inhalation, max effect: max effect: 45sec45sec

1.1. TThus important that it is hus important that it is used at the early used at the early onset of contractions & discontinued after onset of contractions & discontinued after peak of contractions.peak of contractions.

2.2. NNo effect on hepatic, renal, cardiac or o effect on hepatic, renal, cardiac or pulmonary functions.pulmonary functions.

3.3. SaSafe & economic fe & economic but does not provide but does not provide complete & predictable analgesia complete & predictable analgesia

4.4. Lack of co-operation of patientLack of co-operation of patient

5.5. Atmospheric pollutionAtmospheric pollution

S/E:S/E: Dizziness, Nausea, Dysphoria. Dizziness, Nausea, Dysphoria.

OTHER VOLATILE ANESTHETICSOTHER VOLATILE ANESTHETICS

Trichloroethylene, Methoxyflurane, Isoflurane(0.2%), Trichloroethylene, Methoxyflurane, Isoflurane(0.2%), Enflurane(1%), Sevoflurane(2-3%), Desflurane(0.2%)Enflurane(1%), Sevoflurane(2-3%), Desflurane(0.2%)

Isonox(0.2% isoflurane + Entonox)Isonox(0.2% isoflurane + Entonox)

Advantage of subanesthetic conc:Advantage of subanesthetic conc:

a) Lack of irritation to respiratory tracta) Lack of irritation to respiratory tract

b) Pleasant odour b) Pleasant odour

Disadvantages:Disadvantages:

a) Technical diff in safe administration & scavenginga) Technical diff in safe administration & scavenging

b) Requirement of specific vapourisers (c) drowsiness b) Requirement of specific vapourisers (c) drowsiness

d) unpleasant smell (e) high cost (f) accidental d) unpleasant smell (e) high cost (f) accidental overdoseoverdose

SYSTEMIC ANALGESICS:SYSTEMIC ANALGESICS:

OPIOID ANALGESICS:OPIOID ANALGESICS:

a) For parturients who request analgesia other than a) For parturients who request analgesia other than epiduralepidural

b) Those who cannot receive neuraxial analgesiab) Those who cannot receive neuraxial analgesia

Nearly all parenteral opioid analgesics & sedatives readily Nearly all parenteral opioid analgesics & sedatives readily cross the placenta and can affect the fetus.cross the placenta and can affect the fetus.

Other S/E:Other S/E:

1. CNS depression1. CNS depression

2. Loss of beat to beat variability in FHR 3.↓ed Fetal movt.2. Loss of beat to beat variability in FHR 3.↓ed Fetal movt.

4. Maternal respiratory depression, nausea, vomiting, 4. Maternal respiratory depression, nausea, vomiting, delayed gastric emptyingdelayed gastric emptying

MEPIRIDINE:MEPIRIDINE:

M/C used M/C used

I/V, 25-50mg, acts within 5-10minI/V, 25-50mg, acts within 5-10min

I/M, 50-100mg, peak effect in 40-50minI/M, 50-100mg, peak effect in 40-50min

Max fetal depression seen in Max fetal depression seen in 10-20min in I/V10-20min in I/V & & 1-1-3hrs in I/M3hrs in I/M

Analgesia lasts for 3-4hrs, so c/b Analgesia lasts for 3-4hrs, so c/b given when given when delivery not expected for around 4hrsdelivery not expected for around 4hrs

Causes less respiratory depression than Causes less respiratory depression than morphine in neonatemorphine in neonate

S/E:S/E: loss of beat to beat variability of FHR loss of beat to beat variability of FHR

FENTANYL:FENTANYL:

25-100µg I/V, OA: 3-10min, DOA: 60min (1hr)25-100µg I/V, OA: 3-10min, DOA: 60min (1hr)

However maternal respiratory depression outlasts However maternal respiratory depression outlasts analgesia.analgesia.

Lower doses m/b assoc with little or no neonatal Lower doses m/b assoc with little or no neonatal resp depression and has no effect on Apgar scores.resp depression and has no effect on Apgar scores.

Used in labour as an I/V bolus or as an analgesic Used in labour as an I/V bolus or as an analgesic administered by means of PCA system.administered by means of PCA system.

Advantage:Advantage: s/c, orally, as patch. s/c, orally, as patch.

Disadv: Use limited in labour by Disadv: Use limited in labour by side effects side effects & & short short DOADOA..

REMIFENTANIL:REMIFENTANIL:

1.1. Short acting, Short acting, µ opioidµ opioid receptor receptor agonistagonist

2.2. Biperidine derivative with a normal opioid Biperidine derivative with a normal opioid configuration but contains an ester linkage that configuration but contains an ester linkage that allows metabolism by non specific esterases. allows metabolism by non specific esterases.

3.3. Thus it has an extremely rapid plasma Thus it has an extremely rapid plasma clearance & offset of action→ clearance & offset of action→ Fetal exposure Fetal exposure minimizedminimized

4.4. Risk of accumulation of drug in the mother & Risk of accumulation of drug in the mother & fetus in PCA regime, thus fetus in PCA regime, thus close monitoring is close monitoring is essential essential with with supplementary oxygensupplementary oxygen and ready and ready access to access to naloxone.naloxone.

BUTARPHANOL:BUTARPHANOL:

κκ agonist & agonist & µµ antagonist antagonist

1-2mg i/m, i/v; DOA: 4hrs1-2mg i/m, i/v; DOA: 4hrs

NALBUPHINE:NALBUPHINE:

Partial Partial κκ agonist & potent agonist & potent µµ antagonist antagonist

10mg, i/v; OA: 2-3min; i/m; OA: 10-15min; DOA: 10mg, i/v; OA: 2-3min; i/m; OA: 10-15min; DOA: 6hrs6hrs

Both demonstrate a ‘Both demonstrate a ‘ceiling effectceiling effect’ i.e. ’ i.e. increasing increasing doses does not produce further respiratory doses does not produce further respiratory depression.depression.

S/ES/E: Rapidly crosses placenta, dizziness, : Rapidly crosses placenta, dizziness, drowsiness, nausea, vomitingdrowsiness, nausea, vomiting

SEDATIVE-TRANQUILIZERS:SEDATIVE-TRANQUILIZERS:

BarbituratesBarbiturates1.1. Prolonged depressant effect on fetusProlonged depressant effect on fetus

2.2. Antanalgesic effectAntanalgesic effect

3.3. Used in latent phase of labour when delivery not Used in latent phase of labour when delivery not anticipated for 12-24hrsanticipated for 12-24hrs

Phenothiazines, Phenothiazines, 1.1. Relieve anxiety Relieve anxiety

2.2. Dec opioid requirementDec opioid requirement

3.3. Control emesis during labour Control emesis during labour

BDZ BDZ

1.1. Provide sedation & anxiolysisProvide sedation & anxiolysis

2.2. Used in very early labourUsed in very early labour

3.3. Diazepam: maternal & fetal plasma levels are Diazepam: maternal & fetal plasma levels are equal within minutesequal within minutes

4.4. Floppy baby syn.Floppy baby syn.

5.5. Midazolam: rapid i/v amnesia, deep sedationMidazolam: rapid i/v amnesia, deep sedation

FLOPPY BABY SYNDROMEFLOPPY BABY SYNDROME

Diazepam & ChlordiazepoxideDiazepam & Chlordiazepoxide

1.1. Late third trimester use and exposure during Late third trimester use and exposure during labour. labour.

2.2. Symptoms vary from mild sedation, hypotonia, Symptoms vary from mild sedation, hypotonia, and reluctance to suck, to apnoeic spells, and reluctance to suck, to apnoeic spells, cyanosis, and impaired metabolic responses to cyanosis, and impaired metabolic responses to cold stress.cold stress.

3.3. Symptoms persist from hours to months after Symptoms persist from hours to months after birth.birth.

ANTAGONISTS:ANTAGONISTS:

NALOXONE: NALOXONE: 0.1mg/kg iv0.1mg/kg iv

Can be administered in 3 ways:Can be administered in 3 ways:

a) To the mother with each dose of opioida) To the mother with each dose of opioid

b) To the mother 10-15min before deliveryb) To the mother 10-15min before delivery

c) To the neonate immediately after deliveryc) To the neonate immediately after delivery

The rationale for administering opioid & The rationale for administering opioid & opioid antagonist simultaneously is to provide opioid antagonist simultaneously is to provide max analgesia with min respiratory depressionmax analgesia with min respiratory depression

REGIONAL TECHNIQUESREGIONAL TECHNIQUES

Most effective means of providing analgesia Most effective means of providing analgesia for labour & deliveryfor labour & delivery

Most commonly Most commonly used are:used are:

1.1. Lumbar Epidural AnalgesiaLumbar Epidural Analgesia

2.2. Combined Spinal Epidural analgesiaCombined Spinal Epidural analgesia

3.3. Continuous Spinal AnalgesiaContinuous Spinal Analgesia

4.4. Alternative regional anesthetic techniquesAlternative regional anesthetic techniques

Benefits:Benefits:

1.1. Pt awake & able to participate.Pt awake & able to participate.

2.2. Effective pain relief without appreciable Effective pain relief without appreciable motor blockmotor block

3.3. Reduction in maternal catecholaminesReduction in maternal catecholamines

4.4. Drug induced fetal depression unlikelyDrug induced fetal depression unlikely

5.5. Means to rapidly achieve surgical anesthesiaMeans to rapidly achieve surgical anesthesia

IndicationsIndications

1.1. Pt. requestPt. request

2.2. Diff. ETI anticipatedDiff. ETI anticipated

3.3. Prolonged labourProlonged labour

4.4. Fetal prematurityFetal prematurity

5.5. Breech extractionBreech extraction

6.6. Multiple gestationMultiple gestation

ContraindicationsContraindications

1.1. Local infectionLocal infection

2.2. CoagulopathyCoagulopathy

3.3. ThrombocytopeniaThrombocytopenia

4.4. Allergy to LAAllergy to LA

5.5. Pt. refusalPt. refusal

6.6. Preexisting neuro disPreexisting neuro dis

7.7. Spine disordersSpine disorders

8.8. Some Cardiac disSome Cardiac dis

LUMBAR EPIDURAL ANALGESIALUMBAR EPIDURAL ANALGESIA

Provides effective analgesia during both Provides effective analgesia during both stages of labour.stages of labour.

Traditionally given when labour is well Traditionally given when labour is well established.established.

However, However, recent studiesrecent studies suggest: suggest:

1. There is min. to no alterations in duration & 1. There is min. to no alterations in duration & outcome of labour.outcome of labour.

2. No increase in need for labour augmentation 2. No increase in need for labour augmentation with oxytocics.with oxytocics.

3. No diff. in the rates of vaginal delivery.3. No diff. in the rates of vaginal delivery.

4. Significant 4. Significant ↑ ↑ in maternal satisfaction .in maternal satisfaction .

Thus, it s/b generally initiated when the Thus, it s/b generally initiated when the parturient wants it & the obstetrician approves it.parturient wants it & the obstetrician approves it.

Commonly Commonly accepted criteria accepted criteria for placement:for placement:

1.1. No fetal distressNo fetal distress

2.2. Good regular contractions 3-4 min apart & lasting Good regular contractions 3-4 min apart & lasting abt. 1 minabt. 1 min

3.3. Adequate cervical dilatation i.e. 3-4cmAdequate cervical dilatation i.e. 3-4cm

4.4. Engagement of the fetal head.Engagement of the fetal head.

REGIONAL TECHNIQUESREGIONAL TECHNIQUES

Patient Evaluation & Preparation:Patient Evaluation & Preparation:

1.1. Informed consent must be obtained.Informed consent must be obtained.

2.2. Procedure & potential complications to be Procedure & potential complications to be explained explained

3.3. Full check of emergency equipments to be doneFull check of emergency equipments to be done

4.4. Intravenous infusion to be startedIntravenous infusion to be started

5.5. Appropriate maternal & fetal monitoring to be Appropriate maternal & fetal monitoring to be in place before starting the procedurein place before starting the procedure

TECHNIQUETECHNIQUE

1.1. Sitting/ lateral positionSitting/ lateral position2.2. 500-1000ml IVF500-1000ml IVF3.3. Place catheter as usualPlace catheter as usual4.4. Test dose→ to check accidental I/V or SA placementTest dose→ to check accidental I/V or SA placement 2-3ml lignocaine, bupivacaine2-3ml lignocaine, bupivacaine sensory block in 2-3min; motor in 3-5minsensory block in 2-3min; motor in 3-5min For IV placement:For IV placement: a) LA + 15-20µg epinephrine→ HR↑ 20-30bpm in 30-60sa) LA + 15-20µg epinephrine→ HR↑ 20-30bpm in 30-60s b) 3ml lignocaine→ tinnitus/ peri-oral numbnessb) 3ml lignocaine→ tinnitus/ peri-oral numbness c) 1-2ml air into epidural catheter→ monitoring precordialc) 1-2ml air into epidural catheter→ monitoring precordial doppler doppler

Safe practice:Safe practice:

1.1. Catheter aspirationCatheter aspiration

2.2. Test dose for possible I/v; SA placementTest dose for possible I/v; SA placement

3.3. Injecting total dose in small increments (<5ml) & Injecting total dose in small increments (<5ml) & observe pt for signs of LA toxicity observe pt for signs of LA toxicity

Epidural space in PregnancyEpidural space in Pregnancy

1.1. Volume ↓ Volume ↓

thus, Segmental dose req↓thus, Segmental dose req↓

Catheter should not be placed during Catheter should not be placed during contraction→ iv placement contraction→ iv placement

2.2. Pressure ↑: Non pregnant: -1cmH2OPressure ↑: Non pregnant: -1cmH2O

End of 1End of 1stst stage: 4-10cm H2O stage: 4-10cm H2O

So, test used is LOR & not –ve pr. techniqueSo, test used is LOR & not –ve pr. technique

If signs of IV/SA inj. absent ,If signs of IV/SA inj. absent , Initial block options:Initial block options:

1.1. Bupivacaine 0.0625-0.125%, 10-15mlBupivacaine 0.0625-0.125%, 10-15ml

2.2. Ropivacaine 0.1-0.2%Ropivacaine 0.1-0.2%

3.3. Fentanyl 50-100µg or Sufentanil 10-20µg in a 10ml volFentanyl 50-100µg or Sufentanil 10-20µg in a 10ml vol

Subsequent analgesia optionsSubsequent analgesia options

1.1. Intermittent (as above)Intermittent (as above)

2.2. Continuous infusion @ 10-15ml/hrContinuous infusion @ 10-15ml/hr

Bupivacaine 0.0625-0.125% without opioidsBupivacaine 0.0625-0.125% without opioids

Bupivacaine 0.04-.125% / Ropivacaine 0.05-0.2%+ fentanyl Bupivacaine 0.04-.125% / Ropivacaine 0.05-0.2%+ fentanyl 1-5µg/ml or Sufentanil 0.03-0.05µg/ml1-5µg/ml or Sufentanil 0.03-0.05µg/ml

3.3. PCEA: PCEA:

Bupivacaine 0.04-.125% + fentanyl 2µg/ml Bupivacaine 0.04-.125% + fentanyl 2µg/ml

5ml bolus, 5-10min lockout 5ml bolus, 5-10min lockout @ 5-10ml/hr, hourly @ 5-10ml/hr, hourly limit 30mllimit 30ml

Pt supine (Lt ut. Displacement)Pt supine (Lt ut. Displacement) OxygenOxygen BP monitoring every 1-2min for 1BP monitoring every 1-2min for 1stst 15min, then 15min, then

every 5min thereafter until block wears off.every 5min thereafter until block wears off. If pt in lateral position, turn side-side to If pt in lateral position, turn side-side to

prevent one sidedprevent one sided

Check sensory, motor analgesia level Check sensory, motor analgesia level regularlyregularly

Adjust infusion rate acc to dermatome levelAdjust infusion rate acc to dermatome level If ↓ analgesia→ repeat test dose before If ↓ analgesia→ repeat test dose before

giving drug (IV/SA migration) giving drug (IV/SA migration) If dev of motor block (SAB migration) → If dev of motor block (SAB migration) →

locate catheter position by aspiration, repeat locate catheter position by aspiration, repeat test dosetest dose

Epidural Opioids:Epidural Opioids:

1.1. MorphineMorphine

Dose: upto 7.5mg; OA : 30-60minDose: upto 7.5mg; OA : 30-60min

>5mg → resp depression>5mg → resp depression

Only effective in early 1Only effective in early 1stst stage of labour stage of labour

2.2. MeperidineMeperidine

Dose 50-100mg; DOA: 1-3hrDose 50-100mg; DOA: 1-3hr

3.3. Fentanyl Fentanyl

Dose: 50-150µg; OA: 5-10min; DOA: 1-2hrDose: 50-150µg; OA: 5-10min; DOA: 1-2hr

4.4. Sufentanil Sufentanil

Dose 5-15µg → 1hr; 40-50µg → 2hrDose 5-15µg → 1hr; 40-50µg → 2hr

Epidural LAEpidural LA1.1. BupivacaineBupivacaine

Adv: Adv:

Disad: CardiotoxicityDisad: Cardiotoxicity

2.2. LignocaineLignocaine

Dose: 0.75-1%Dose: 0.75-1%

3.3. 2 Chloroprocaine2 Chloroprocaine

Rapid onset, brief DOA (hydrolysis by plasma ChE)Rapid onset, brief DOA (hydrolysis by plasma ChE)

Disad: a) Apparent antagonism of subsequent opioidDisad: a) Apparent antagonism of subsequent opioid

b) Additive for low pH– Arachnoiditisb) Additive for low pH– Arachnoiditis

4.4. Ropivacaine: less cardiotoxic than BupivacaineRopivacaine: less cardiotoxic than Bupivacaine

Blocks Na channels→ stops cond.

↑lipid solubility→ enters CM easily

Epidural Opioid + LA Epidural Opioid + LA 1.1. Action on 2 diff sites→ SynergyAction on 2 diff sites→ Synergy

2.2. More chances of spont vaginal deliveryMore chances of spont vaginal delivery

3.3. Neonatal Adverse effects ↓Neonatal Adverse effects ↓

4.4. Less LA reqd→↓ motor block, so can pushLess LA reqd→↓ motor block, so can push

Choice of CatheterChoice of Catheter1.1. Multi holedMulti holed

2.2. Single holedSingle holed

Spinal Opioid AnalgesiaSpinal Opioid Analgesia

1.1. Single SA shot of LA/OpioidSingle SA shot of LA/Opioid

2.2. Early labour/ distressed parturientEarly labour/ distressed parturient

3.3. When catheter placement is diff d/t obesity, When catheter placement is diff d/t obesity, anatomical distortion, multiparousanatomical distortion, multiparous

4.4. Effective analgesia without systemic effect of Effective analgesia without systemic effect of opioidopioid

5.5. Early ambulationEarly ambulation

6.6. In cardiac pts to prevent inc in HR & CO d/t painIn cardiac pts to prevent inc in HR & CO d/t pain

7.7. Very advanced 1Very advanced 1stst stage & requiring instrumental stage & requiring instrumental delivery .delivery .

8.8. Disadv:Disadv:

1.1. Morphine: 0.25-0.5mg, OA: 40-60min; DOA 4-6hrMorphine: 0.25-0.5mg, OA: 40-60min; DOA 4-6hr

2.2. Sufentanil: 10µg, OA: rapid; DOA: 60-180minSufentanil: 10µg, OA: rapid; DOA: 60-180min

Disadv: a) pruritis , nausea, vomiting b) ↓SBPDisadv: a) pruritis , nausea, vomiting b) ↓SBP

c) resp depression d) variations in c) resp depression d) variations in FHRFHR

3. Fentanyl: 10-25µg, OA: rapid; DOA: 30-120min3. Fentanyl: 10-25µg, OA: rapid; DOA: 30-120min

4. Meperidine: 10-20mg, effective in advanced 4. Meperidine: 10-20mg, effective in advanced labourlabour

Continuous spinal analgesiaContinuous spinal analgesia1.1. In c/o dura puncture, pass 28G microcatheterIn c/o dura puncture, pass 28G microcatheter

2.2. But , inc chances of complicationsBut , inc chances of complications

Combined Spinal EpiduralCombined Spinal Epidural

1.1. Rapid onset with sacral coverageRapid onset with sacral coverage

2.2. Min risk of toxicityMin risk of toxicity

3.3. Dec risk of impaired motor blockDec risk of impaired motor block

4.4. Early ambulation possibleEarly ambulation possible

5.5. Ability to prolong duration of analgesiaAbility to prolong duration of analgesia

6.6. Can be useful if operative delivery neededCan be useful if operative delivery needed

7.7. Greater satisfaction as greater degree of Greater satisfaction as greater degree of controlcontrol

8.8. Reduces incidence of problems with epiduralReduces incidence of problems with epidural

Methods:Methods:1.1. Epidural catheter with spinal needle in lower Epidural catheter with spinal needle in lower

spacespace

2.2. Epidural needle beside spinal needle, same Epidural needle beside spinal needle, same spacespace

3.3. Needle through needle techniqueNeedle through needle technique

S/E:S/E:1.1. Fetal bradycardia ( sudden dec in CA)Fetal bradycardia ( sudden dec in CA)

2.2. Dec UBF (epi-norepi imbalance → unopposed Dec UBF (epi-norepi imbalance → unopposed αα adrenoceptor effect)adrenoceptor effect)

ComplicationsComplications

ImmediateImmediate

1.1. Misplaced injectionMisplaced injection

2.2. High/ Total SpinalHigh/ Total Spinal

3.3. HypotensionHypotension

4.4. LA induced LA induced ConvulsionConvulsion

5.5. Cardiac ArrestCardiac Arrest

DelayedDelayed

1.1. PDPHPDPH

2.2. Transient backacheTransient backache

3.3. Urinary retentionUrinary retention

4.4. Epidural Epidural hematoma/abcesshematoma/abcess

5.5. MeningitisMeningitis

6.6. Neurological deficitNeurological deficit

Paracervical BlockParacervical Block

1.1. SimpleSimple

2.2. LA injected into submucosa of fornix just lateral to LA injected into submucosa of fornix just lateral to Cx to block n. transmission through paracervical Cx to block n. transmission through paracervical ganglionganglion

3.3. Frankenhauser GanglionFrankenhauser Ganglion: Contains all visceral, : Contains all visceral, sensory n. fibres from uterus, Cx, upper vaginasensory n. fibres from uterus, Cx, upper vagina

4.4. Somatosensory fibres from perineum are not blockedSomatosensory fibres from perineum are not blocked

5.5. So, So, 11stst stage analgesia stage analgesia

6.6. Disad: Fetal bradycardia→ →neonatal depressionDisad: Fetal bradycardia→ →neonatal depression

7.7. LA toxicity, postpartum neuropathy, infectionLA toxicity, postpartum neuropathy, infection

8.8. OA: 2-10min; DOA: upto 2hrsOA: 2-10min; DOA: upto 2hrs

Pudendal blockPudendal block

1.1. Pudendal n. S 2,3,4 Pudendal n. S 2,3,4

2.2. Supplies lower p/o vagina, vulva, perineumSupplies lower p/o vagina, vulva, perineum

3.3. Transvaginal approach→ LA deposited behind Transvaginal approach→ LA deposited behind each sacrospinous ligamenteach sacrospinous ligament

4.4. Forceps/Vaginal deliveryForceps/Vaginal delivery

5.5. Effective for 2Effective for 2ndnd stage stage

6.6. Complications: IV inj, Retroperitoneal Complications: IV inj, Retroperitoneal hematoma, Subgluteal abscesshematoma, Subgluteal abscess

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