Pain Relief in Labor: A Long and Winding Road

Pain Relief in Labor:
A Long and Winding
Road
Christopher Viscomi, MD
Director: Acute Pain Medicine
and Regional Anesthesia
Co-Director: OB Anesthesia
Goals
• History: From Bibles to Burlington
• Pain in labor- anatomy and
physiology
• Non-medical therapies
• Intravenous therapies
• Spinals and epidurals
• Comparative studies
• Answers to frequent questions
• Original Sin
Garden of Eden
• God punished Eve: “In sorrow thou
shalt bring forth children.” –Genesis
3:16
• Formed the basis of 1800 years of
opposition to pain relief in labor.
• 1591: Lady Euframe MacAlyane of
Edinburgh, Scotland: Burned at the
Stake for asking for labor analgesia.
1847: Sir James Young Simpson
• Professor of Midwifery,
U. of Edinburgh
• Queen’s Physician in
Scotland
• Considered one of the
world’s foremost
obstetricians
• Discovered anesthetic
properties of
chloroform
Simpson: OB Anesthesiologist
• January 19, 1847- Ether
• November 8, 1847-Chloroform
• Labeled a heretic by the religious
community.
• Criticized in the medical community
1

“In sorrow thou shalt bring forth
children” –Genesis 3:16
• Simpson argued persuasively that
“sorrow” was improperly translated.
It was more properly “labor”, “toil”,
or “physical exertion”.
• Noted that God had permitted Adam
to sleep when the rib was harvested
to create women. Thus, clearly
anesthesia was divinely acceptable.
Medical Opposition:
Dr. Charles Meigs
• American obstetrician of equal stature to
Simpson.
• Prominent New England family.
Descendents of Revolutionary War heroes,
first governor of Ohio, and founder of the
University of Georgia
• “uterine pain is inseparable from
contractions. Any pain relief diminishes
contractions.”
• “Pregnancy and labor are normal, and
should not be interfered with powerful
prescriptive drugs.”
Meigs vs. Simpson
• Simpson” “All pain
is without
physiologic value.
It often degrades
or destroys those
who experience it.”
• “it will be
necessary to define
the precise effect
of ether on uterine
muscles.”
1853: John Snow and Queen
Victoria
Snow and the London Cholera
Epidemic: The Broad Street
Pumphouse
John Snow
• Compatriot of James Simpson
• Best know as the physician who solved the
London Cholera epidemic
• Clinical and research interest in
anesthesia, particularly chloroform.
• 4000 anesthetics from 1847-53, with only
one death.
• Secretly called to Buckingham Palace by
Queen Victoria for her delivery of Prince
Leopold
2

The Fallout
William Benson, Archbishop of
Canterbury
• The Lancet, Editor and Chief: “I
cannot imagine anyone could have
advised the administration of
chloroform to her majesty during a
natural labor.”
• The Royal Court denied the event for
4 years until the birth of Princess
Beatrice in 1857. Chloroform was
again administered by Dr. Snow.
Religious Acceptance
1847 in America
• 1855 Queen’s acceptance of “that
blessed chloroform” for childbirth.
• Archbishop of Canterbury's (leader of
the Anglican/Episcopal Church)
daughter receives chloroform for
labor pains. He refuses to criticize
her.
Henry Wadsworth Longfellow
• Famous poet and scholar.
• His wife, Fanny Appleton Longfellow
expecting third child. She described her
first two deliveries “excruciating
suffering.”
• Henry went to Dr. Nathan Keep, a Dean of
Medicine at Harvard, and developer of an
etherization device.
• Fanny’s “sufferings were greatly
mitigated” “with no unpleasant
symptoms”, “healthy girl”
Fanny Longfellow
• “I am sorry many thought me rash in
trying the ether. I had heard such a
thing had succeeded abroad, where
doctors apply this blessing more
boldly than our timid American ones.
I feel proud to be a pioneer for less
suffering for womankind.”
• “Gratitude, however, cannot be
bestowed on those men who quarrel
if this is a gift of God.”
3

Mesmerism
• “I have the idea of magnetizing a
pregnant woman before delivery.
Imagine such a discovery as birth
without pain! Unfortunately Genesis
doesn’t want this.” Dr. Grubert,
Lyons, France, 1836
• 1844, English Mesmerist JP Lynell
provided a week of mesmerism
culminating in painless delivery.
Mesmerism in America
• Dr. William Fahnestock (Lancaster, PA)
practiced “somnambulism”, which was
similar to “animal magnetism” and
“mesmerism”, producing a “stuporous
trance.”
• Reported two deliveries managed without
pain. Mrs. Susan Herr had lost her
eyesight and use of her legs with a
previous painful delivery. Sight, mobility,
and painless labor were all obtained with
“somnambulistic trance” during her next
delivery.
Mesmerism vs. Ether
• Mesmerists attempted hypnotic states for
surgery, but were generally unsuccessful.
• Famous British surgeon Sir Robert Liston
proclaimed “This Yankee dodge (ether),
gentlemen, beats mesmerism hollow!”
• Never-the-less, for the last 160 years,
hypnotic states have successfully achieved
labor pain relief.
Dr. August Bier
• University of Berlin, 1898
• Pinnacle of Western Medicine in
1890s
• He and an assistant (Dr. Henselbach)
hammered spinal needles into each
other backs, injected cocaine.
• Reported first spinal anesthetic, first
spinal headaches.
Description of Spinal Anesthesia
• “I extinguished my cigar on
Henselbach’s knee- it was sensed
only as warmth.”
• “I struck his shin with an anvil, but
no pain was noted.”
• “His testicle was placed in a surgical
clamp. This evoked sweating and
some nausea, but no pain.”
4

Bier Footnotes
• 1944: Mrs. Bier makes remark at
Berlin cocktail party
• Next day: both disappear. Mrs. Bier
dies in prison 1945
• Dr. Bier discovered confused, near
starvation at insane asylum, 1946
1900: Spinal anesthesia in
obstetrics
• Dr. Oskar Kreis, University of Munich
• First to use spinal anesthesia for
childbirth.
• Technique generally used only for
desperate surgical deliveries because
of high rates of infection and other
complications.
The poppy seed
Opium
• Available since the Romans
• Crude extracts from poppy seeds
produced mixtures of morphine,
codeine, and opium
• Taken orally, smoking, or by
smearing seed paste on skin followed
by multiple puncture with a small
knife.
Syringe + Better chemistry =
“Twilight sleep”
• 1899: Von Steinbuchel’s and Gauss
• Described combining morphine with
a plant extract (scopolamine).
• Amnesia was prominent, and
considered desirable.
• Patient demand exceeded physician
endorsement, with most physicians
opposing the practice.
5

World War I
• Great intermingling of
European and
American Medicine
• Post- war, obstetrics
grew into a
scientifically advanced
specialty
• Effects of anesthesia
on the newborn
scientifically
investigated
Dr. Paul Zweifel,
Demonstrated the presence of
chloroform in newborn blood
and urine.
Twilight Sleep
Virginia Apgar, MD
• Caution urged: The Freiburg method
of Dammerschlaf or twilight sleep.
Am J. Obstet Gynecology, 1914
• First reports of newborns breathing
slowly or not at all after mothers
received “twilight sleep”.
Apgar Score
1950-70s: Contrasting movements
• First attempt to quantify
effects of labor and
medications on the birth
condition of the neonate.
• Important to have person
other than obstetrician or
midwife do the score.
• Allowed comparisons of
pain relief techniques:
Spinal anesthesia had
better scores compared to
general anesthesia.
Grantly Dick-
Read, MD
Caudal-Epidural Injection
6

Grantly Dick-Read: Natural
Childbirth and Prenatal Education
• English Gynecologist
• Rejected the need for pain relieving drugs
during childbirth: pain was principally a
product of preconceived fear and tension (
he called it the 'fear-tension-pain'
syndrome). He believed that women who
were properly prepared could control labor
pain themselves - without having to resort
to medication. In order to achieve this, he
stressed the importance of education,
exercise and relaxation.
PART II: The Anatomy and
Physiology of Labor Pain
• Discrete nerve pathways for labor
pain.
• Separate nerve fibers transmit pain
form the uterus and from the vagina.
First Stage of Labor
• Onset of
contractions until
cervix fully dilated.
• Uterine
contractions
sensed in abdomen
and back
• Nerve fibers go
from uterus to the
spinal cord (T10-
L1).
Second Stage of Labor
• Baby begins to
descend into
vagina
• Distention of
vagina and rectal
pressure
transmitted via
paired “pudendal
nerves” into the
spinal column in
the scrum.
Transmission of Pain Signals
From sensory nerve
To Dorsal horn of
Spinal Cord
To Spinothalamic Track
To Brainstem
To Thalamus
To Cerebral cortex
(conscious pain
experience)
7

Spinal Cord
Pain Control Options
• First Stage of
Labor:
• Paracervical nerve
block (rare)
• Epidural/spinal
(common)
• Narcotics
• Non-pharmaco.
(hypnosis, massage,
breathing techniques)
• Second stage of
labor:
• Pudendal nerve
block
• Epidural/spinal
• Non-pharmacologic
Pudendal and paracervical blocks
Epidural
Pudendal Nerve Block
Paracervical Nerve block
Part III: “Non-Medical Therapies”
• Hypnosis- best studied
• Education
• Massage
• Breathing techniques
• Water
• Walking
Hypnosis
• Multiple theories of how it works,
including altered neuro-transmitters,
increased natural narcotics
(endorphins), suppression of
excitatory neurons.
• Evidence is that it works well as an
adjunct during painful surgical
procedures.
• Evidence is that it works well during
labor.
8

Hypnosis as adjunct to minor
surgery
Hypnosis for Pain Relief in Labor
and Childbirth: a Systematic
Review
• Br. J. Anaesth, 2004
• 5 Randomized Clinical
Trials, 3 of good quality
• Results of these three
combined: “Metaanalysis”
• Need for pain relief
drugs
• Self rating of pain
Hypnosis: Systematic review
Hypnosis:
Advantages/Disadvantages
• 50% decrease in women requesting
other analgesics
• Of those choosing narcotic injection,
they received less than non-hypnosis
patients
• Hypnosis patients rated their pain as
less severe compared to control
patients
• PROS:
• No drugs
• No allergic
reactions
• No needles
• No placental drug
transfer
• Potential costsavings
• Limitations
• Patient
commitment
• Preparation:
typically at least 6
sessions
• Hypnotist available
• Substantial number
still go on to
receive IV drugs or
epidural
Education
• Grantly Dick-Read stressed prenatal
education as a key to less pain
• Less fear=less pain
• Scientific evidence is lacking: no
randomized clinical trials.
• Non-randomized studies: lower pain
scores and less analgesics if prenatal
classes attended.
Massage, Counter-pressure
• No randomized, placebo-controlled
scientific study
• No harm likely.
• May have benefit
9

• No prospective
randomized trial.
• Multiple
retrospective
endorsements
• Some controversy
about low initial
Apgar scores with
underwater births.
Water birth
• 2000+ years of use
• Very simple to give:
intravenous,
intramuscular, oral,
through skin
• Onset of effect rapid
• Can be repeated as
necessary
• Can still get an
epidural later
Narcotics
Downsides of narcotics
• Limited pain relief
• Maternal sedation and nausea,
neonatal effects
• Predictor of need to “resuscitate” the
newborn: Quadruples need
• Reversal drug-naloxone+breathing
assistance. No difference by 6
hours.
My bias
• Use narcotics very early in labor as a
sleep aid.
• “I just need a little help at the peaks
of contractions, and a bit of rest inbetween
contractions.”
• Not for serious pain relief, or those
wanting a clear-headed recollection
of labor.
Epidural Labor Analgesia
• I am an
anesthesiologist.
• The culture of
above.
• My pay does not
change if you do or
do not get an
epidural during
your labor.
Epidural Labor Analgesia
• Pros:
• The gold standard
for pain relief in
labor.
• Alert mom
• Compared to
narcotics, greatly
reduced newborn
resuscitation rates.
• Very high
satisfaction
• Cons:
• Prolongs labor 1 hour
• 15 more minutes of
pushing
• 1% risk of headache
• 1:23,000 risk of nerve
injury
• Walking restricted
• ?Bladder catheterized
10

What do epidurals do to natural
labor?
• Very difficult to ethically examine.
• It is unethical to randomize women
who want pain relief to an epidural
vs. a placebo.
• Severe labor pain predicts long labor
and high chance of Cesarean
delivery.
• Large selection bias in observational
studies
Selection Bias
• The undoing of many research
studies.
• Observational and retrospective
studies always have selection bias.
• Prospective, Randomized, Placebo-
Controlled, Double-Blinding is best.
The Clinical Significance of Pain and
Cognitive Activity in Latent Labor
• Wuitchik M, Bakal D, and Lipshitz J.
Obstetrics and Gynecology 1989
• 115 women, low risk, first
pregnancy, in spontaneous labor
• Psychological scoring test for pain
given during latent phase of labor.
• Pain scores categorized as
“discomforting”, “distressing”, and
“horrible/excruciating”
Wuitchik, et al.
• Epidurals not available
• Completely observational study
• Related pain assessment in latent
phase (early labor, cervical dilation
< 5 cm) with duration of labor and
mode of delivery
Pain and Labor Duration
Phase Discomforting Distressing Horrible/
excruciating
Latent 391 585 866
Active 230 382 574
Total 1 st
Stage (min)
621 967 1440
11

Pain
Intensity
Pain and Labor Outcome
Spontaneous Forceps Cesarean
Discomforting 70.4% 29.6% 0.0%
Distressing 53.6% 39.3% 7.1%
Horrible
Excruciating
31.6% 42.1% 26.3%
Had epidurals been available…
• The “horrible/excruciating” group
was heading for a long labor and
high chance of Cesarean delivery.
• The Horrible/excruciating group
would very likely have requested
epidurals in great numbers in early
labor.
• If this had happened, then epidurals
would have been blamed for long
labors, C/S.
Narcotics Vs. Epidural
JAMA, 1998, Meta-analysis
• All RCTs of epidural vs. narcotics in labor
• Better pain relief with epidural
• Higher patient satisfaction with epidural
• No change in Cesarean delivery rate.
• 4x higher newborn resuscitation with
narcotic
• 1 hour longer total labor in 1 st pregnancy
• More maternal fevers with epidural.
• More “assisted” deliveries with epidural.
When is “too early” to get an
epidural?
• What we know:
• 3 RCTs
• Women contracting
regularly, cervix
dilating, > 2 cm
• No advantage found in
waiting until later in
labor for the epidural.
• That is, if you are sure
you want an epidural.
When is too late?
• No evidence-based response.
• My experience with patients almost
or completely dilated: 50%-50%
• Can a person cooperate with the
procedure?
• Often a single spinal injection is
chosen.
• Be well educated.
• Listen to your
body.
• Be flexible in your
plans.
• Only get as much
as you need.
Parting words
12