Advances in Labor Analgesia

7/31/2019 Advances in Labor Analgesia

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Advances in Labor

Analgesia

Luis Lahud, M.D.

Norman Bolden, M.D.

Department of Anesthesiology

MetroHealth Medical CenterMay 3rd, 2005

Cleveland, OH


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Contents

Introduction

PCEA

CSE Pros

Cons

Review article

Protocols and Cocktails

Discussion


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INTRODUCTION


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From 1985 to present use of epidural

analgesia for labor has increased from 10% toover 50% of laboring women in the U.S.

Advances include low dose epidurals,

walking epidurals, PCEA, and CSE

Early: increased doses of LA = increased SE

PDPH 7-10%

OB/GYN perspective


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Adding opioids < MB

Walking epidurals: < MB meant betteroutcomes

No evidence of improved laborpattern/outcome with ambulation

Women dont walk even if they can Monitoring problems Techniques that allow walking may be

better whether or not patient ambulates


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Effect of Low-Dose Mobile vs. Traditional

Epidural Techniques on Mode of Delivery:

A Randomized Controlled TrialCOMET Study, Lancet 2001

1054 nulliparous women were randomized into 3groups to receive either a traditional epid (0.25%BUP), a low-dose CSE, or a low-dose infusion epid

Increased rate of normal vaginal delivery with CSEand low-dose infusion

Decreased rate of instrumental vaginal delivery

Increased rate of CS with traditional epidural


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PCEA


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Introduced in 1988

Small basal dose

PCEA less med overall


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PCEA VS. CONTINUOUSGambling et al., Can J Anaesth 1988

Epidural initiated: 8 ml

0.25% BUP

0.125% BUP

PCA: 4 ml basal, 4 ml bolus,

Lockout 20 min, 16 ml/hr max

CIEA: 12 ml/hr infusion


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PCEA VS. CONTINUOUSGambling et al., Can J Anaesth 1988

PCEA (n=14) CIEA (n=11)

______________________________________________________________

Duration (h) 7.0 0.6 5.8 0.6

# demands/hr 1.9 0.4 1.2 0.2

Dose of BUP/hr 11.2 0.85 15.2 0.5


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PCEA + CI vs. PCEA only Both groups provide good analgesia

Both use less than continuousNo benefit with basal rate over demand

only


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Ferrante et al. 1994Background infusion increases drug use by

30%

No obvious benefit in pain relief

Background infusion decreases physician top-

ups

Only physician administer top-ups associatedwith hypotension


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BACKGROUND VS. DEMAND

ONLY?Ferrante et al. 1994

Group N CI(ml/h)

DD

(ml)

Lockout

(min)

BUP/hr (mg)-1rst stage

BUP/hr (mg)-2nd stage

# Physicianvisits/doses

DO 15 0 3 10 9.7 1.3 6.7 1.5 12 4.2

CI (3)15

3 3 10 11.8 1.4 8.9 0.8 8.3 3

CI (6) 15 6 3 10 11.7 0.9 12.2 1.0 1.6 1.2

CI (12) 15 12 0 N/A 16.0 0.7 16.7 1.1 7.0 3.1

Bupivacaine 0.125% with 2 mcg/ml fentanyl Loading dose: 0.5% bupivacaine for S5 T10 level


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PCEA compared to CEI in an ultra-low-

dose regimen for labor pain relief : a

randomized study

Eriksson, Gentele and Olofsson Acta Anaesthesiologica Scandinavica 2003

80 parturients (40 per group)

Ropivacaine 0.1% + SUF 0.5mcg/ml

Test dose + 5ml loading dose PCEA: 4ml doses, 20min lockout

CEI: 6ml/hr

Rescue: 5ml if VAS > 5


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CONCLUSIONS: PCEA group used less drug ( 5.2 v 6.9ml/hr)

PCEA group had shorter labor (296min v

357min, p< 0.001)

Pts titrated themselves to VAS ~ 3


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PCEA at MH

Test dose

Loading dose: 6 -10cc of 0.125% BUP with 2mcg/cc

of fentanyl

Basal infusion: 8 12cc of 0.11% BUP with 2mcg/cc

of fentanyl

Demand dose: 5cc with 15 min lockout max 30cc/hr


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Issues with PCEA

Patient/Nurse education Treat pain early Emphasize that we are available Call us if 2 PCEA attempts dont work ONLY patient pushes button

Equipment

Record keeping

Maintain patient contact


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PCEA CONCLUSIONS

Easy modification of existing practice

Fewer MD visits required

May allow lower concentration of drugs with betteranalgesia

Lower drug usage

Very popular with patients


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CSE


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The ideal labor analgesic: Rapid onset

Long duration

Easy to administer

No side effects on mother No side effects on baby

Allow ambulation, unrestricted expulsive efforts

No effect on length of labor or mode of delivery

Is CSE the ideal labor analgesic?


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Advantages of CSE

Rapid onset of analgesia

Reliable, fewer failed, or patchy blocks

Effective sacral analgesia in advancedlabor

Less motor block


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Better patient satisfaction

Aids epidural localization in difficult backs

Faster cervical dilation in early nulliparas

Side effects are acceptably low


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Rapid Onset of Analgesia

Most dramatic feature; analgesia is often

nearly complete before the epidural cath is

taped up and the tray discarded

Van de Velde randomized 110 parturients to

epid. BUP 0.125% w sufentanil and

epinephrine or IT sufentanil. The time toeffective analgesia was significantly shorter

in the CSE group (326 22 vs. 766 79sec).


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Nickells randomized women to epid. or SA BUP

and fentanyl. The time to first painless

contraction was shorter in the CSE group ( 10 5.7 vs. 12.1 6.5min)

Hepner randomized women to receive 10ml of

0.0625% BUP + fentanyl 2mcg/ml + epinephrine+ bicarbonate epidurally or 25mcg fentanyl and

2.5mg BUP IT

26/26 patients had a VAS < 3 within 5min in

CSE group, only 17/24 in the epidural group

Does a few minutes advantage in analgesic

onset matter?


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Better Blocks

Quality of analgesia is improved by CSE

Norris retrospectively compared epid. andCSE techniques in 1661 women who

received either technique and found a lower

incidence of failed blocks and a greater

incidence of bilateral symmetrical analgesiaw CSE


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A retrospective analysis in a large academicmedical center involving near 20 thousandpatients found incidences of overall failure,IV epid cath, wet tap, inadequate epidanalgesia and cath replacement were all

lower in patients receiving CSE

Sacral analgesia is difficult to obtain withconventional epidural, CSE is good at

providing it

CSE is an obvious choice in advanced labor


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A number of mechanisms may explain this

advantage:

1. One cannot obtain CSF using the needle-

through-needle technique unless the epid

needle is positioned near the mid line ofthe actual epid space

2. There may be passage of LA from the

epidural space into the IT space via the

dural hole3. There may be synergism between epid

and spinal blocks, such that one

enhances the other


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Less Motor Block

CSE associated with less total LA use for a givendegree of analgesia

In a randomized trial, Collis found 12/98 patients in theCSE group, compared to 32/99 in the epid group hadleg weakness at 20min

The difference widened to 10% vs. 80% at 5hr

MB may be minimized or made equivalent to CSE withuse of low dose and/or PCEA for epid analgesia

Requirements for anesthesiologist intervention arelower w CSE regardless of technique


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Better Patient Satisfaction

Several studies have found better patient

satisfaction scores with CSE vs. conventional

epid. Others have found no difference, butnone have found better satisfaction with

conventional epid analgesia


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Better in Difficult Backs

No randomized trial has yet appeared

CSE has been associated with improved

chances of adequate analgesia in parturients

with scoliosis or other causes of a difficult

back


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Progress of Labor

Patients progress rapidly through labor

One explanation for an apparent increase in FHRabnormalities occurring after CSE is this rapidprogress

2 large randomized trials have confirmed an increasein the spontaneous vaginal delivery rate with CSE vs.

conventional epid analgesia

As is the case with epidural analgesia, the CS rate isnot increased with CSE


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Side Effects

PDPH

Fetal bradycardia/FHR changes

Pruritus

Infection

Neurotrauma

Other side effects


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PDPH Rate ~ 1%

CSE technique might actually decrease the

incidence of dural puncture with the epid needle by

allowing the anesthesiologist to confirm an

equivocal loss of resistance by passage of a pencil

point spinal needle rather than advancing the large

bore epid needle futher


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Fetal bradycardia/ FHR changes

Incidence of 11-30% Meta - analysis of 24 randomized trials including

over 3,500 patients comparing CSE toconventional epid analgesia found no difference in

the rate of FHR changes but an increase in the riskof bradycardia Usually a reduction in uterine activity (decreasing

or interrupting oxytocin administration, or shortacting tocolytic administration), raising maternalBP, position change, or simply patience willresolve the problem


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The meta analysis showed no difference in

the rate of CS due to bradycardia or for allindications, and neonatal Apgar scores wereequivalent

Pruritus 3-95% of patients Effect is time limited, peak at 30min and

largely resolved within 1hr Prophylactic Ondansetron Patient satisfaction remains high


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Other side effects

Hypotension

Subarachnoid migrationRespiratory depression


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On the other hand..How fast do we need a block to be? Nickells et al. noted that the time to first painless

contraction with CSE was 10 5.7 vs. 12.1 6.5min with the epid technique. With a mean

difference of 2min, how clinically significant is this? In the study by Hepner mentioned before at 5min

the VAS was < 3 in 26/26 with a CSE vs. 17/24with an epid; However, no difference in maternal

satisfaction, motor blockade or number of timesthe anesthesiologist was called to intervene.

Why pay more for CSE?


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Walking and CSE vs. Epidural

No data to suggest a real difference in labor outcome

More maternal satisfaction with being mobile but

outcome is the same

Instrumental delivery rate and CS rates are virtuallythe same

Epid can be used to allow mobility if that is your goal


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Side Effects of CSE

Collis et al. (1994) found the failure rate of the ITportion as high as 10%. Duration of the spinal portion90min (mean) and highly variable

Norris et al. noted the spinal part failed in 4.9%

Expected side effects include pruritus, mild decrease

in maternal BP, PDPH

Best and worst of both worlds

C f F il f CSE


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Causes of Failure for CSE

Technique


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Infection

Meningitis and epid abscess have been reported

There are least 8 cases of spinal meningitis related to

a CSE

There is also a case of epid abscess after a CSE forlabor

Conversely spinal anesthesia for elective CS doesnot carry these risks


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Neurotrauma

Cord trauma has been reported with the CSEtechnique in at least 5 cases

In a report of 7 cases with damage to the conus

medullaris following spinal anesthesia by Reynolds ofSaint Thomas Hospital in London, 4 were patientswho had received a CSE and 3 after a single shotspinal (6 in total were obstetric patients)

In all cases, an atraumatic needle was used, 25 or 27gauge Whitacre and the anesthesiologist believed tobe at L2-3


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Epid has proven to be relatively safe over many

years. If placed in error at T12-L1, for example,there is little concern in good hands

A CSE at that level is a disaster, with penetration

of the cord likely

In 43% of women the cord extends to L2

Numerous studies have shown that we are often1-2 spaces off, which can cause cord trauma witha CSE


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Van Gessel et al. demonstrated that 59%of dural punctures were performed 1 or 2

spaces higher than assumed

Broadbent et al. demonstrated in a group

of experienced anesthesiologists that

when they believed they were at L3-L4, in85% of the cases the space was 1 to as

many as 4 segments higher


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FHR Changes

Numerous studies of varying quality

Bradycardia more frequent

Management: LUD, fluids, oxygen, treat BP ifapplicable, IV or SL NTG has been shown to beeffective in treating fetal bradycardia associated

with uterine hyperactivity

However, there is no data demonstrating anincreased risk of CS due to CSE

The Risk of Cesarean Delivery with


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The Risk of Cesarean Delivery with

Neuraxial Analgesia Given Early vs. Late

in LaborWong et al, NEJM, February 17, 2005

Epid analgesia initiated early in labor (cervix < 4cmdilated) has been associated with an increased risk ofCS. It is unclear whether this is due to the analgesia or

to other factors

Women who request analgesia early in labor frequentlyreceive systemic opioid analgesia

Hypothesis: Initiating and maintaining neuraxialanalgesia early in labor with IT opioid as part of a lowdose LA technique would not increase the risk of CS

when compared with systemic opioid analgesia


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884 Consented

First request for analgesia;

Cervical examination performed

750 Randomly assigned

(cervix


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Results

728 subjects were included in the analysis

The groups were similar at baseline, except

that the systemic analgesia group had agreater % of subjects with dilation 1.5cm atfirst request for analgesia (42 vs. 30.9%)

The rate of CS was not significantly differentbetween the groups (IT 17.8 vs. 20.7% SA)


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No significant difference in the rate of

instrumental vaginal delivery between thegroups (IT 19.6 vs. 16% SA)

No significant differences in the indicationsfor CS or in the % of subjects who received

oxytocin; however, the maximal rate of

oxytocin infusion was higher in the systemic

analgesia group


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Average pain score between 1st and 2nd request foranalgesia was significantly lower in the IT analgesiagroup, so was duration of neuraxial analgesia

Higher incidence of prolonged and latedecelerations in FHR in IT group

Neonatal outcomes were not significantly differentbetween the groups

Greater incidence of 1min Apgar scores below 7 inthe SA group (24 vs. 16.7%)


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In this randomized trial IT opioid analgesia ascompared with SA in early labor did not increase

the rate of CS

The data suggests that an early request for

analgesia, or increased use of analgesics early in

labor may be markers for other risk factors for CS

Women who have more pain and require more

analgesia may be at increased risk for CS


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Analgesia may have indirect effects in theprogress of labor

IT fentanyl decreases maternal concentration ofcirculating epinephrine

It is possible this decreases epinephrine-inducedtocolysis, resulting in faster labor

An alternative explanation is that SA negativelyinfluences the progress of labor


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PROTOCOLS

AND

COCKTAILS


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UCSF

CSE: 2.5mg BUP + 25mcg fentanyl

No test dose

Infusion started


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Brigham and Womens Hospital

PCEA: 20ml BUP 0.125% + fentanyl

2mcg/ml, then 6 ml/hr infusion, 6ml bolus,

15min lockout

CSE: 2.5mg BUP + fentanyl 25mcg

No test dose, start PCEA


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Northwestern

PCEA: 0.0625% + 2 mcg/ml fentanyl. 15ml/hr

basal infusion, 5ml bolus, 10min lockout,

30ml/hr max. If patient requires manual

rebolusing they change to 0.11% BUP

CSE: early labor 25mcg fentanyl + test dose

Regular labor or multip: 15mcg fentanyl + 2.5mgBUP + test dose. Start PCEA


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MHMC

PCEA as detailed before

CSE: 1.25mg BUP + 15mcg fentanyl +epinephrine


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DISCUSSION

Documents

Advances in Labor Analgesia