Upload
narasimha-reddy
View
1.591
Download
4
Embed Size (px)
Citation preview
Analgesia for Labor and DeliveryAnalgesia for Labor and Delivery
ALWAYSALWAYS controversial ! controversial !
““Birth is a natural process”Birth is a natural process”
Women should suffer!!Women should suffer!!
Concerns for mother’s safetyConcerns for mother’s safety
Concerns for babyConcerns for baby
Concerns for effects on labor Concerns for effects on labor
HistoryHistory Garden of EdenGarden of Eden
Original SinOriginal Sin
God punished Eve: “In sorrow thou shalt bring forth children.” God punished Eve: “In sorrow thou shalt bring forth children.” Genesis 3:16Genesis 3:16
Formed the basis of Formed the basis of 1800 years of opposition1800 years of opposition to pain relief in labor.to pain relief in labor.
15911591
Lady Euframe MacAlyane of Edinburgh, Scotland: Lady Euframe MacAlyane of Edinburgh, Scotland: was Burned was Burned
at the Stake because asking for labor analgesia.at the Stake because asking for labor analgesia.
HISTORYHISTORY 1847 – James Young Simpson; ETHER1847 – James Young Simpson; ETHER 1853 – John Snow ; CHLOROFORM1853 – John Snow ; CHLOROFORM
- Queen Victoria, 8- Queen Victoria, 8th th childchild
“ “The inhalation lasted fifty-three The inhalation lasted fifty-three
minutes. The chloroform was given . The chloroform was given
on a handkerchief in fifteen minim on a handkerchief in fifteen minim
doses; the Queen expressed herself doses; the Queen expressed herself
as greatly relieved by the as greatly relieved by the
administration.”administration.”
Chloroform a’ la reineChloroform a’ la reine
Chloroform a’ la reineChloroform a’ la reine
“Dr Snow gave me the blessed
chloroform and the effect was soothing,
quieting and delightful beyond measure”
History contd..History contd..
1855 1855
Religious acceptanceReligious acceptance Archbishop of Canterbury's (leader ofArchbishop of Canterbury's (leader of the Anglican/Episcopal Church) daughter received the Anglican/Episcopal Church) daughter received
chloroform for labor pains. He refused to criticize.chloroform for labor pains. He refused to criticize.
1860-1940 : Dark ages of obstetric anesthesia1860-1940 : Dark ages of obstetric anesthesia
HistoryHistory
August Bier ,…………….., August Bier ,……………..,
Virginia Apgar ,…Virginia Apgar ,…
1900 1900 ::
Oskar Kreis Oskar Kreis , used spinal anesthesia for , used spinal anesthesia for childbirth for the first timechildbirth for the first time
1933 : John Cleland – pain pathways1933 : John Cleland – pain pathways
1943 : Hingson – Continuous caudal1943 : Hingson – Continuous caudal
1949 : Flowers - Continuous lumbar epid.1949 : Flowers - Continuous lumbar epid.
DEFINITION OF PAINDEFINITION OF PAIN
ISAP - ISAP - AS AN UNPLEASANT SENSORY AS AN UNPLEASANT SENSORY AND EMOTINAL EXPERIENCE AND EMOTINAL EXPERIENCE ASSOCIATED WITH ACTUAL ASSOCIATED WITH ACTUAL POTENTIAL TISSUE DAMAGE (OR) POTENTIAL TISSUE DAMAGE (OR) DESCRIBED IN TERMS OF SUCH DESCRIBED IN TERMS OF SUCH DAMAGE.DAMAGE.
TERMINOLOGYTERMINOLOGY
NOCICEPTIONNOCICEPTION:DETECTION,TRANSDUCTION,AND:DETECTION,TRANSDUCTION,AND
TRANSMISSION OF NOXIOUS STIMULITRANSMISSION OF NOXIOUS STIMULI
NOCICEPTORSNOCICEPTORS:FREE NERVE ENDINGS ACTIVATED:FREE NERVE ENDINGS ACTIVATED
BY NOXIOUS STIMULI.BY NOXIOUS STIMULI.
PHYSIOLOGIC PAINPHYSIOLOGIC PAIN:NOXIOUS STIMULI ACTIVATING:NOXIOUS STIMULI ACTIVATING
||
NOCICEPTORS ACCOMPANIED BY WITHDRAWALNOCICEPTORS ACCOMPANIED BY WITHDRAWAL
PATHOLOGIC PAINPATHOLOGIC PAIN: NON NOXIOUS STIMULI PRODUCING PAIN: NON NOXIOUS STIMULI PRODUCING PAIN
PHYSIOLOGY OF PAINPHYSIOLOGY OF PAIN
PATHWAYSPATHWAYS
MEDIATORSMEDIATORS
PERCEPTIONPERCEPTION
PATHWAYSPATHWAYS
PERIPHERAL AFFERENT(FIRSTORDER NEURON)PERIPHERAL AFFERENT(FIRSTORDER NEURON)
||
DORSAL ROOT GANGLIONDORSAL ROOT GANGLION
||
DORSAL HORN(SECOND ORDER)DORSAL HORN(SECOND ORDER)
||
CONTRALATERAL HEMISPHERECONTRALATERAL HEMISPHERE
||
SPINOTHALAMIC TRACTSPINOTHALAMIC TRACT
||
THALAMUS THALAMUS
MECHANISMS MECHANISMS
PERIPHERALPERIPHERAL
CENTRALCENTRAL
PERIPHERAL MECHANISMSPERIPHERAL MECHANISMS
NOCICEPTORS:NOCICEPTORS: 1.NON MYELINATED(c-fibers) 1.NON MYELINATED(c-fibers)
2.MYELINATED(A-DELTA)2.MYELINATED(A-DELTA) POLYMODAL.POLYMODAL. A-DELTA- SHARP,HEAT,PRESSUREA-DELTA- SHARP,HEAT,PRESSURE C-FIBERS-DULL BURNING PAIN.C-FIBERS-DULL BURNING PAIN. PATHOLOGICAL PAIN-A-BETA.PATHOLOGICAL PAIN-A-BETA.
CHEMICAL MEDIATORSCHEMICAL MEDIATORS
BRADYKININBRADYKININ HISTAMINEHISTAMINE EICOSANOIDSEICOSANOIDS SUBSTANCE-PSUBSTANCE-P 5-HT5-HT ATPATP H2 IONH2 ION OPIOID PEPTIDESOPIOID PEPTIDES
CENTRAL MECHANISMSCENTRAL MECHANISMS
NOCICEPTIVE AFFERENTS DORSAL ROOT NOCICEPTIVE AFFERENTS DORSAL ROOT GANGLION DORSALHORNGANGLION DORSALHORN
C&SOME A-DELTA SUPERFICIAL LAMINA(1&2)C&SOME A-DELTA SUPERFICIAL LAMINA(1&2)SOME A-FIBERS —LAMINA - 5SOME A-FIBERS —LAMINA - 530% -C-FIBERS —DOUBLE BACK THROUGH30% -C-FIBERS —DOUBLE BACK THROUGH VENTRAL ROOTVENTRAL ROOT1&5 -------THALAMUS1&5 -------THALAMUSLAMINA 2—SUBSTANTIA GELATINOSA (INHIBITORY)LAMINA 2—SUBSTANTIA GELATINOSA (INHIBITORY)
““THE GATE CONTROL THEORY OF PAIN”THE GATE CONTROL THEORY OF PAIN”
MODULATORS AT SPINALMODULATORS AT SPINAL CORD CORD
OPIOID PEPTIDESOPIOID PEPTIDES
BIOGENIC AMINESBIOGENIC AMINES
OTHERSOTHERS
SUPRASPINAL MODULATIONSUPRASPINAL MODULATION
PERIAQUEDUCTAL GREY(PAG) MATTERPERIAQUEDUCTAL GREY(PAG) MATTER DESCENDING INHIBITORY PATHDESCENDING INHIBITORY PATH LOSS OF RESPONSE TO NOXIOUS STIMULILOSS OF RESPONSE TO NOXIOUS STIMULI RESPONSE TO STIMULI-3 WAYSRESPONSE TO STIMULI-3 WAYS
““ON CELLS” FACILITATE NOCICEPTIVE ON CELLS” FACILITATE NOCICEPTIVE TRANSMISSIONTRANSMISSION
““OFF CELLS” INHIBITS TRANSMISSIONOFF CELLS” INHIBITS TRANSMISSION ““NEUTRAL CELLS”NO CHANGE IN FIRINGNEUTRAL CELLS”NO CHANGE IN FIRING
Grading Of PainsGrading Of Pains
PAIN PATHWAYSPAIN PATHWAYS
1st stage of labor – mostly visceral1st stage of labor – mostly visceral Dilation of the cervix and distention of the
lower uterine segment Dull, aching and poorly localized Slow conducting, C fibers, T10 to L1
2nd stage of labor – mostly somatic2nd stage of labor – mostly somatic Distention of the Distention of the pelvic floor, vagina and pelvic floor, vagina and
perineumperineum Sharp, severe and well localizedSharp, severe and well localized Rapidly conducting, A-delta fibers,S2 to S4Rapidly conducting, A-delta fibers,S2 to S4
Labor Pain & Stages of Labor
Eltzschig, Leiberman, Camann, NEJM 348; 319:2003Eltzschig, Leiberman, Camann, NEJM 348; 319:2003
Effects of labor painEffects of labor pain
Maternal hyperventillationMaternal hyperventillationHypocarbia – Uteroplacental vasoconstrictionHypocarbia – Uteroplacental vasoconstriction
- ODC to left- ODC to left↑↑O2 consumptionO2 consumption ↑↑Cardiac output, ↑BPCardiac output, ↑BP ↑ ↑Maternal plasma catecholaminesMaternal plasma catecholamines
Fetal acidosis and hypoxiaFetal acidosis and hypoxia
Ill effects Of Pain?Ill effects Of Pain?
High risk parturient – Pre-eclampsiaHigh risk parturient – Pre-eclampsia
- Cardiac disease- Cardiac disease
- Asthma- Asthma
Marginal uteroplacental circulationMarginal uteroplacental circulation
Prolonged laborProlonged labor
Labor Analgesia
Non-Pharmacological Pharmacological
Non-PharmacologicalNon-Pharmacological
Psycho prophylaxis – Lamaze, DoulaPsycho prophylaxis – Lamaze, DoulaTENSTENSAcupunctureAcupunctureHydrotherapyHydrotherapy Intradermal water inj.Intradermal water inj.
ACUPUNTUREACUPUNTURE
Generally two local points and two distal points on the Generally two local points and two distal points on the arms or on the legs are selected.arms or on the legs are selected.
Begin Acupuncture 4 weeks before the expected time ofBegin Acupuncture 4 weeks before the expected time of delivery.delivery. Needles are placed once a week using the specific points.Needles are placed once a week using the specific points.
PointsPoints LI.4 Hegu, SP.6 Saninjiao, Extra NeimaLI.4 Hegu, SP.6 Saninjiao, Extra NeimaPC 6 (Neiguan), Du.20,Du.2,Du6, GB.21,PC 6 (Neiguan), Du.20,Du.2,Du6, GB.21,He.7(shenmen)He.7(shenmen)
TENSTENS
Beneficial in patients with moderate to severe Beneficial in patients with moderate to severe contraction pains in an otherwise reasonably contraction pains in an otherwise reasonably
normal labor.normal labor. Very popular in Europe.Very popular in Europe. Easy to apply, non-toxic and frequently Easy to apply, non-toxic and frequently
effective.effective. 4 electrodes are placed one on either side of 4 electrodes are placed one on either side of
the the spine in the lower thoracic region (T 10) and spine in the lower thoracic region (T 10) and
one one on either side of the spine in the sacral area.on either side of the spine in the sacral area. The patient may control up to 3 levels of The patient may control up to 3 levels of
intensityintensity of stimuli, and she can switch it off if she of stimuli, and she can switch it off if she
wishes.wishes.
Pharmacological
Systemic Medications
Inhalational Regional Blocks
Factors Determining Fetal Drug LevelsFactors Determining Fetal Drug Levels Lipid solubilityLipid solubility
Molecular size Molecular size
Total dose of drugTotal dose of drug
Concentration gradientConcentration gradient
Maternal metabolism and excretionMaternal metabolism and excretion
Degree of ionizationDegree of ionization
pKa of drug, maternal and fetal pHpKa of drug, maternal and fetal pH
Protein binding - mother and fetusProtein binding - mother and fetus
Uterine blood flowUterine blood flow
Time for equilibrium to occurTime for equilibrium to occur
Systemic Opioids in LaborSystemic Opioids in Labor
Easy administrationEasy administration
InexpensiveInexpensive
No needlesNo needles
Avoids complications of regional blockAvoids complications of regional block
Does not require skilled personnelDoes not require skilled personnel
Few serious maternal complicationsFew serious maternal complications
Perceived as “natural”Perceived as “natural”
Advantages:Advantages:
Systemic Opioids - DisadvantagesSystemic Opioids - Disadvantages
Placental transferPlacental transfer
Inadequate pain reliefInadequate pain relief
Maternal sedationMaternal sedation
Nausea, vomiting, gastric stasisNausea, vomiting, gastric stasis
Fetal heart rate effects:Fetal heart rate effects:
Loss of beat-to-beat variabilityLoss of beat-to-beat variability
Sinusoidal rhythmSinusoidal rhythm
Dose-related maternal / neonatal depressionDose-related maternal / neonatal depression
Newborn neurobehavioral depressionNewborn neurobehavioral depression
Potential Fetal/Neonatal Effects Potential Fetal/Neonatal Effects
Low 1 and 5 min Apgar scoresLow 1 and 5 min Apgar scores
Respiratory acidosisRespiratory acidosis
Naloxone/ ventilatory assistance may be neededNaloxone/ ventilatory assistance may be needed
Neurobehavioral depression - dose dependentNeurobehavioral depression - dose dependent
Occasionally, prolonged observation in NICU neededOccasionally, prolonged observation in NICU needed
MepridineMepridine: 50-100mg IM / 25-50mgIV: 50-100mg IM / 25-50mgIV
onset: 45mins / 5minsonset: 45mins / 5mins
neonatal depr: 3hrs / 20 minsneonatal depr: 3hrs / 20 mins
optimal time: >4hrs / <1hroptimal time: >4hrs / <1hr
FentanylFentanyl: 50-100: 50-100µg/hr, µg/hr, peaks @ 3-5minspeaks @ 3-5mins
RemifentanilRemifentanil : : ½life 6mins, 0.5mirogms/kg½life 6mins, 0.5mirogms/kg
Butraphanol, Nalbhuphine, PhenothiazinesButraphanol, Nalbhuphine, Phenothiazines
IV-PCA Fentanyl during Labor IV-PCA Fentanyl during Labor
Loading dose -50-100Loading dose -50-100µµgg
No background infusionNo background infusion
10-12.510-12.5µµg bolusg bolus
8-10 min lockout8-10 min lockout
4 hour limit - 300 mcg4 hour limit - 300 mcg
Pulse oximeter when large doses Pulse oximeter when large doses
Inhalation Analgesia Inhalation Analgesia
Advantages:Advantages:
Easy to administer (no needles Easy to administer (no needles
or PDPH)or PDPH)
“ “Satisfactory” analgesia variableSatisfactory” analgesia variable
Minimal neonatal depressionMinimal neonatal depression
Entonox (N2O:O2 = 50:50), %,
Inhalational AnalgesiaInhalational Analgesia
Isoflurane ( 0/2%)Isoflurane ( 0/2%) Enflurane (0/2%)Enflurane (0/2%) Desflurane (0/2%)Desflurane (0/2%)
LIMITED USELIMITED USE
Drowsiness ,Unpleasant smell, High cost,Drowsiness ,Unpleasant smell, High cost,
Accidental overdoseAccidental overdose
Inhalation Analgesia Inhalation Analgesia
Disadvantages:Disadvantages:
Decreased uterine contractility (except NDecreased uterine contractility (except N22O)O)
Rapid induction of anesthesia in pregnancyRapid induction of anesthesia in pregnancy
Risk of unconsciousness and aspirationRisk of unconsciousness and aspiration
Difficulties with scavenging in labor roomsDifficulties with scavenging in labor rooms
Regional blocksRegional blocks
Paracervical BlockParacervical Block
Local bilateral injection near the cervixLocal bilateral injection near the cervix Given during 1Given during 1stst stage of labor stage of labor Lasts about 2 hoursLasts about 2 hours
DisadvantageDisadvantage fetal bradycardiafetal bradycardia Lidocaine toxicityLidocaine toxicity
Pudendal BlockPudendal Block
Perineal anaesthesiaPerineal anaesthesia Second stage of laborSecond stage of labor
Most effective & Least depressantMost effective & Least depressant Great versatility – Extent & DurationGreat versatility – Extent & Duration Reduces maternal CatecholsReduces maternal Catechols ↑↑Intervillous blood flowIntervillous blood flow
Improved Uteroplacental perfusionImproved Uteroplacental perfusion Low dose LA – Low dose LA – NO Effect on Uterine activityNO Effect on Uterine activity Low dose opioids – Low dose opioids – NO neonatal depressionNO neonatal depression
Neuraxial Blocks - advantagesNeuraxial Blocks - advantages
Regional Analgesia - Neonatal Effects Regional Analgesia - Neonatal Effects
Uterine perfusion maintained Uterine perfusion maintained
FHR changes:FHR changes:
baseline variabilitybaseline variability
periodic decelerations (due toperiodic decelerations (due to maternal catechols?) maternal catechols?)
Apgar scores, acid-base status - unaffectedApgar scores, acid-base status - unaffected
Neurobehavioral effects absentNeurobehavioral effects absent
LA toxicity - LA toxicity - extremelyextremely rare rare
Profound hypotension - possible fetal compromiseProfound hypotension - possible fetal compromise
IndicationsIndications
PAIN EXPERIENCED BY A WOMAN IN LABORPAIN EXPERIENCED BY A WOMAN IN LABOR
ACOG and ASA statedACOG and ASA stated
“ “ in the absence of a medical contraindication, maternal in the absence of a medical contraindication, maternal request is a sufficient medical indication for pain request is a sufficient medical indication for pain relief…”relief…”
Points of controversyPoints of controversy When?When? Who?Who? How?How?
Particularly beneficialParticularly beneficial
Hypertensive disordersHypertensive disorders Cardiac diseaseCardiac disease AsthmaAsthma Diabetes Diabetes Prolonged lobor/ Oxytocin augmentationProlonged lobor/ Oxytocin augmentation PrematurityPrematurity Multiple gestationMultiple gestation Vaginal breech deliveryVaginal breech delivery
Blunts Haemodynamic response
Depressant effects of opioids avoided
Am J Obstet Gynecol 1983;147:13-5.
Maternal catecholamines decrease during labor Maternal catecholamines decrease during labor after lumbar epidural analgesia. after lumbar epidural analgesia.
ContraindicationsContraindications
ABSOLUTEABSOLUTE Patients refusal Patients refusal Inability to cooperateInability to cooperate Increased intracranial Increased intracranial
pressure pressure Infection at the site Infection at the site Frank coagulopathyFrank coagulopathy Hypovolemic shockHypovolemic shock
RELATIVERELATIVE Systemic maternal infectionSystemic maternal infection Preexisting neurological Preexisting neurological
deficiencydeficiency Mild coagulation Mild coagulation
abnormalitiesabnormalities Relative hypovolemiaRelative hypovolemia Poor communicationPoor communication
GOALS OF LABOR ANALGESIAGOALS OF LABOR ANALGESIA
Dramatically reduce pain of laborDramatically reduce pain of labor Should allow parturients to participate in birthing Should allow parturients to participate in birthing
experienceexperience Minimal motor block to allow ambulationMinimal motor block to allow ambulation Minimal effects on fetusMinimal effects on fetus Minimal effects on progress of laborMinimal effects on progress of labor
How to Achieve Goals:How to Achieve Goals:What you put in:What you put in:
Drugs, concentrations, combinationsDrugs, concentrations, combinations
How you deliver it:How you deliver it:
Intermittent boluses, Continuous, PCEAIntermittent boluses, Continuous, PCEA
How much you give:How much you give:
Low Vs. High infusion ratesLow Vs. High infusion rates
Neuraxial BlocksNeuraxial Blocks
Epidural aloneEpidural alone Combined epidural and spinalCombined epidural and spinal Spinal aloneSpinal alone
Local anaesthetics(LA) aloneLocal anaesthetics(LA) alone Opioids and LAOpioids and LA Opioids aloneOpioids alone
Spinal opioids alone: very high risk ptsSpinal opioids alone: very high risk pts Epidural opioids alone: High dosesEpidural opioids alone: High doses Spinal LA alone: Saddle block, 6mg bupivacaineSpinal LA alone: Saddle block, 6mg bupivacaine
Epidural LA aloneEpidural LA alone Epidural LA + Opioid Epidural LA + Opioid ± Adjuvants± Adjuvants Combined Spinal & epidural – LA+Opioid Combined Spinal & epidural – LA+Opioid
± Adjuvants± Adjuvants Continuous spinal – LA ± OpioidsContinuous spinal – LA ± Opioids
Neuraxial BlocksNeuraxial Blocks
Choice Of Local AnestheticChoice Of Local Anesthetic
Rapid onset with minimal motor blockRapid onset with minimal motor block Minimal risk of maternal toxicityMinimal risk of maternal toxicity Negligible effects on uterine activity and Negligible effects on uterine activity and
uteroplacental perfusionuteroplacental perfusion Limited uteroplacental transferLimited uteroplacental transfer Long duration of actionLong duration of action
Choice of Epidural LAChoice of Epidural LA
Lignocaine:Lignocaine: Rapid onset, Dense motor block, Risk of Rapid onset, Dense motor block, Risk of cummulative toxicity, UV/MV ratio – 0.6 cummulative toxicity, UV/MV ratio – 0.6
Chlorprocaine:Chlorprocaine:Rapid onset, Low toxicity, Dense block, Rapid onset, Low toxicity, Dense block, Antagonises bupivacaine &poioidsAntagonises bupivacaine &poioids
Bupivacaine( 0.0625%):Bupivacaine( 0.0625%): Good sensory, Minimal motorGood sensory, Minimal motor block, 2hrs, No adverse effects onblock, 2hrs, No adverse effects on labor, UV/MV – 0.3labor, UV/MV – 0.3
Ropivacaine:Ropivacaine: Lower toxicity, ?Less motor block, Less Lower toxicity, ?Less motor block, Less potentpotent
Levobupivacaine:Levobupivacaine: Lower toxicityLower toxicity
Epinephrine Use in LaborEpinephrine Use in Labor May transiently slow laborMay transiently slow labor
Increases motor block, Improves analgesiaIncreases motor block, Improves analgesia
Epinephrine test dose Epinephrine test dose often avoidedoften avoided in labor in labor
Low specificity - maternal heart rate very variable Low specificity - maternal heart rate very variable
Low sensitivity - Low sensitivity - response to sympathomimetics response to sympathomimetics
Increases motor block - prevents ambulationIncreases motor block - prevents ambulation
Potential for Potential for UBF with repeated doses UBF with repeated doses
VeryVery dilute agents - “whole first dose is test dose.” dilute agents - “whole first dose is test dose.”
Epidural Opioids in LaborEpidural Opioids in Labor
Inadequate analgesics if used alone Inadequate analgesics if used alone
Synergize with local anestheticsSynergize with local anesthetics
Speed onset of analgesiaSpeed onset of analgesia
Improve quality of analgesiaImprove quality of analgesia
Permit use of very dilute LA solutionsPermit use of very dilute LA solutions
Help relieve persistent perineal pain and Help relieve persistent perineal pain and
unblocked segmentsunblocked segments
Effect of low conc LA + opioid Effect of low conc LA + opioid
0
10
20
30
40
50
"Traditional" Low-doseInfusion
Spontaneous
Instrumental
C/Section
% % PatientsPatients
****
(Comet Study UK , Lancet 2001;358:19)(Comet Study UK , Lancet 2001;358:19)
BupivacaineBupivacaine 0.25%0.25%
BupivacaineBupivacaine0.1% + fentanyl0.1% + fentanyl
Bupiv 2.5 mgBupiv 2.5 mg+ Fent 25 mcg+ Fent 25 mcg
**
Which Epidural Opioid ?Which Epidural Opioid ?
Fentanyl and SufentanilFentanyl and Sufentanil
Rapid onset, few side effectsRapid onset, few side effects
Sufentanil slightly more effectiveSufentanil slightly more effective
No significant fetal drug accumulationNo significant fetal drug accumulation
No serious adverse neonatal effectsNo serious adverse neonatal effects
Light or “Ultra-light Analgesic Light or “Ultra-light Analgesic Techniques Techniques
BupivacaineBupivacaine
Ropivacaine Ropivacaine + + OPIOIDOPIOID LevobupivacaineLevobupivacaine
Epidural analgesiaEpidural analgesia
Opioid: Fentanyl 1-2 Opioid: Fentanyl 1-2 µg/ml, µg/ml, Sufentanyl 0.2- Sufentanyl 0.2-0.5µg/ml0.5µg/ml
Continuous infusionContinuous infusion Bupivacaine 0.0625%-0.25%,8 -15 ml/hrBupivacaine 0.0625%-0.25%,8 -15 ml/hr Ropivacaine: 0.125%-0.25%, 6 -12 ml/hrRopivacaine: 0.125%-0.25%, 6 -12 ml/hr
Intermittent bolus injectionsIntermittent bolus injections Bupivacaine: 0.125%-0.375%, 5-10 ml, Bupivacaine: 0.125%-0.375%, 5-10 ml,
duration:1-2 hrduration:1-2 hr
Continous EpiduralContinous Epidural
Continuous epidural infusionContinuous epidural infusion““A larger volume of a more dilute agent is more A larger volume of a more dilute agent is more
effective for labor analgesia than a smaller effective for labor analgesia than a smaller volume of higher concentration”volume of higher concentration”
Good pain releifGood pain releifLess motor blockLess motor block Increased maternal hamodynamic stabilityIncreased maternal hamodynamic stabilitySafe drug concentrationsSafe drug concentrationsNo change in neonatal outcomeNo change in neonatal outcome
Good analgesiaGood analgesia Patient autonomyPatient autonomy Less anaesthetist interventions Less anaesthetist interventions Cost effectiveCost effective Lower total doseLower total doseBupivacaine 0.125% + Fentanyl 2Bupivacaine 0.125% + Fentanyl 2µg/ml – 6ml basal µg/ml – 6ml basal
infusion, 3ml bolus, 10min lockout interval, max infusion, 3ml bolus, 10min lockout interval, max 24ml/hr24ml/hr
PCEAPCEA
From Gambling DR et al. Comparison of patient-controlled epidural From Gambling DR et al. Comparison of patient-controlled epidural analgesia and conventional intermittent top up injections during labor. analgesia and conventional intermittent top up injections during labor.
Anesth Analg 1990;70:256-61Anesth Analg 1990;70:256-61..
Combined spinal-epiduralCombined spinal-epidural
Faster onset - intense analgesiaFaster onset - intense analgesia Additional flexibility - epiduralAdditional flexibility - epidural
Very low failure rateVery low failure rate
Minimal motor block if only opioid used for spinalMinimal motor block if only opioid used for spinal
Less need for supplemental bolusesLess need for supplemental boluses IT opioids: Fentanyl 5-25 IT opioids: Fentanyl 5-25 μμg, sufentanil 5-10 g, sufentanil 5-10 μμggEarly labor : opioid ± 0.125 mg bupivacaine; Early labor : opioid ± 0.125 mg bupivacaine;
Advanced labor: opioid ± 2-2.5 mg bupivacaineAdvanced labor: opioid ± 2-2.5 mg bupivacaine
COMBINED SPINAL EPIDURALCOMBINED SPINAL EPIDURAL
Needle” through “Needle” “ Back “ eye”Needle” through “Needle” “ Back “ eye”
Needle” through “Needle” technique is the bestNeedle” through “Needle” technique is the best Can be placed in lateral or sitting positionCan be placed in lateral or sitting position Walking Epidural possibleWalking Epidural possible
Onset of Analgesia: CSE vs. Onset of Analgesia: CSE vs.
Epidural Epidural Collis et al. Lancet 1995;345:1413Collis et al. Lancet 1995;345:1413
0
25
50
75
100
Baseline 5 10 15 20
Time (minutes)
CSE
Epidural
VAPS (0-100)
Combined spinal-epiduralCombined spinal-epidural
Not recommended - morbidly obese, difficult airway Not recommended - morbidly obese, difficult airway or non-reassuring fetal heart rateor non-reassuring fetal heart rate
Two interspace techniquesTwo interspace techniques Needle through needleNeedle through needle
--PDPH: 1% or less, small bore atraumatic needles.PDPH: 1% or less, small bore atraumatic needles.
-Subarchanoid migration of epidural catheter - No added -Subarchanoid migration of epidural catheter - No added risk with CSErisk with CSE
28 or 32-G catheters for 22 or 26-G spinal needles28 or 32-G catheters for 22 or 26-G spinal needles Bupivacaine 2.5mg+25Bupivacaine 2.5mg+25µg fentanyl, µg fentanyl,
1-2ml/hr of bupivacaine 0.125% + 2µg/ml fentanyl 1-2ml/hr of bupivacaine 0.125% + 2µg/ml fentanyl Cauda Equina Syndrome Cauda Equina Syndrome Restricted by FDA in 1992Restricted by FDA in 1992 Ongoing multi-institutional study – 28-G catheters Ongoing multi-institutional study – 28-G catheters
sufentanil ± bupivacainesufentanil ± bupivacaine Appears safeAppears safe
Continuous Spinal AnalgesiaContinuous Spinal Analgesia
Side effects of IT opioidsSide effects of IT opioids Nausea, VomittingNausea, Vomitting PruritisPruritis SedationSedation At very high doses - Resp depressionAt very high doses - Resp depression
- Fetal bradycardia- Fetal bradycardia Stratergy to ↓ side effect - Add LAStratergy to ↓ side effect - Add LA
- Lowest dose opioid- Lowest dose opioid
We are All Ready…Now What? We are All Ready…Now What?
Obstetrician is consulted Obstetrician is consulted Pre-anesthetic evaluation Pre-anesthetic evaluation Pt’s informed consentPt’s informed consent Fetal well-being assessed and reassured Fetal well-being assessed and reassured
(obstetrician?, midwife?, yourself?)(obstetrician?, midwife?, yourself?) Stage of labor/ Cervical dilatationStage of labor/ Cervical dilatation Resuscitation equipment and drugs are Resuscitation equipment and drugs are
immediately availableimmediately available Aspiration prophylaxisAspiration prophylaxis
Conduct of Labour analgesiaConduct of Labour analgesia
Baseline BP, HR, FHR Baseline BP, HR, FHR IV access, Preload 500 -1000mlIV access, Preload 500 -1000ml Perform epidural / CSEPerform epidural / CSE Pregnancy – Physiologic changesPregnancy – Physiologic changes Left lateral / sitting Left lateral / sitting R/O intrathecal/ IV placementR/O intrathecal/ IV placement 3-5cm catheter inside space3-5cm catheter inside space 4ml of the drug4ml of the drug
Monitoring:Monitoring: BP every 1 to 2 min , 20 minBP every 1 to 2 min , 20 min Continuous maternal HR during induction Continuous maternal HR during induction
(pulseoximetry)(pulseoximetry) Continuous FHR monitoringContinuous FHR monitoring Continual verbal communicationContinual verbal communication
After 5mins, 4-8ml of drug » T10-L1 blockAfter 5mins, 4-8ml of drug » T10-L1 block Alternatively continuous infusion /PCEAAlternatively continuous infusion /PCEA Assess progression of laborAssess progression of labor Treat every bolus as test doseTreat every bolus as test dose
Conduct of Labour analgesiaConduct of Labour analgesia
Nursed in lateral positionNursed in lateral position Second stage of labor – S2 -4Second stage of labor – S2 -4 Head end elevation, 4-8ml drug bolusHead end elevation, 4-8ml drug bolus Intermittent techniques – 10-15ml drugIntermittent techniques – 10-15ml drug Prolonged for instrumental delivery / Prolonged for instrumental delivery /
C.sectionC.section
Conduct of Labor analgesiaConduct of Labor analgesia
Inadequate analgesia
Inadequate doseInadequate dose Patency of catheterPatency of catheter Subdural placementSubdural placement Second stage of laborSecond stage of labor Catheter migrationCatheter migration Uterine ruptureUterine rupture
ComplicationsComplications
Hypotension: Hypotension: preloading, LUD, O2, fluid, ephedrinepreloading, LUD, O2, fluid, ephedrine
Inadequate analgesia:Inadequate analgesia:Unintentional intravascular placement: Unintentional intravascular placement:
slow injection of dilute conc – less risk slow injection of dilute conc – less risk ligonocaine – light headedness, perioral numbness, seizures. ligonocaine – light headedness, perioral numbness, seizures. Bupivacaine – Ventricular arrythmia, cardiac arrestBupivacaine – Ventricular arrythmia, cardiac arrest
Unintentional intrathecal placement: Unintentional intrathecal placement: Hypotension, total spinal, PDPHHypotension, total spinal, PDPH
Subdural placement :Subdural placement :patchy block, high levelpatchy block, high level
Fetal Heart Rate
Management of FHR ChangesManagement of FHR Changes
Left uterine displacementLeft uterine displacement
Maternal position changeMaternal position change
OO22 administration administration
STOP OXYTOCIN! STOP OXYTOCIN!
Fetal scalp stimulationFetal scalp stimulation
Nitroglycerin: 400 µg sublingual X 2 (or more)Nitroglycerin: 400 µg sublingual X 2 (or more)
Terbutaline 0.25 mg, subcutaneousTerbutaline 0.25 mg, subcutaneous
Treat hypotensionTreat hypotension
Ephedrine - Ephedrine - epinephrine level; epinephrine level; UBF UBF
Controversial areas
Maternal pyrexia: ↑0.1 C/hr, No infection, No neonatal sepsis
Progress of Labor: ?only minimally prolongs
Rate of C/S: Not increased
Epidural test dose: ? Adrenaline, ?isoprotenerol Careful aspiration
Avoiding Epidural Disasters Avoiding Epidural Disasters
Maintain constant verbal contactMaintain constant verbal contact Always aspirate before each injectionAlways aspirate before each injection Observe for passive return through the catheterObserve for passive return through the catheter Do not inject more than 4 ml of LA at a timeDo not inject more than 4 ml of LA at a time Observe the patient at least 1.5-2 min between bolusesObserve the patient at least 1.5-2 min between boluses If in doubts, repeat test dose. Still in doubts? Replace itIf in doubts, repeat test dose. Still in doubts? Replace it After all, be mentally prepare to treatAfter all, be mentally prepare to treat
1.1. ConvulsionsConvulsions
2.2. Total spinalTotal spinal
3.3. Cardiovascular collapse and arrestCardiovascular collapse and arrest
ConclusionsConclusions
Individualize technique to patient’s goals and Individualize technique to patient’s goals and
stage of laborstage of labor
Optimize management for spontaneous deliveryOptimize management for spontaneous delivery
Provide safe, cost-effective analgesiaProvide safe, cost-effective analgesia
The Ideal Labor AnalgesicThe Ideal Labor Analgesic Good pain reliefGood pain relief
No autonomic block (no hypotension)No autonomic block (no hypotension)
No adverse maternal or neonatal effectsNo adverse maternal or neonatal effects
No motor blockNo motor block
No effect on labor and delivery:No effect on labor and delivery: No increase in C/S rateNo increase in C/S rate
No increase in forceps/vacuum deliveryNo increase in forceps/vacuum delivery
Patient can ambulatePatient can ambulate
Economical: cost and personnelEconomical: cost and personnel