Labour Analgesia

• Dr. Ashok Kumar saxena

• Prof. & Head, Deptt. Anesthesia
GTBH Delhi-95.
UCMS & GTBH,
“Unto the woman he said
said, I will
greatly multiply thy sorrow and thy
conception;
i in
i sorrow thou
h shalt
h l bring
bi
forth children;;”
Genesis 3:16 KJV
Labour pain
 History

• The first anesthetic used in obstetrics

was chloroform and ether in 1848
• 1902- Morphine and Scopolamine were
used to induce a twilight sleep
sleep.
• 1924 Barbituates were added for
sedation
• 1940 Dr.
Dr Lamaze and Read advocated
“natural child birth”
Labour pain?
 Stages of labor

• First Stage- Due to uterine contraction

and cervical dilatation
Afferents accompany Sympathetic
fibres and enter the spinal cord at the
level of T10-L1
• Second Stage- Due to stretching of
Vagina and Perineum
Afferents course along with the
pudendal
d d l nerve att the
th level
l l off S2-S4.
S2 S4
 Methods of Labor analgesia
Pharmacological
Systemic Opioids-
Opioids 1.
1 Pethidine
2. Remifentanil
3 3
3.Morphine-rarely
M hi l used
d
Inhalational-
a at o a Entonox
to o
Epidural Analgesia
Combined Spinal Epidural
 Non-Pharmacological Methods

• Acupuncture
• Hypnosis
• TENS
• Psychoprophylaxis- Acts through
decreasing
dec eas g tthe
e pe
perception
cept o oof pa
pain du
during
g
labour.
Non-pharmacological

Immersion
Acupuncture/acupressure
Hypnosis/Cognitive strategies
TENS
Aromatherapy
 TENS
• Use of electric current produced by a
device for suppressing
pp g pain
p
transmission in nerve fibres.
• Generally TENS is applied at high
frequency (>50 Hz) with an intensity
below motor contraction (sensory
(
intensity)
y) or low frequency
q y ((<10 Hz))
with an intensity that produces motor
contraction
• Role is controversial
 Factors that affect the transfer of a
drug to the fetus
• Amount of drug
• Site of administration
• Drug distribution in maternal tissue
• Maternal metabolism
• Renal or liver excretion of the drugs
and their metabolites
• Lipid solubility and protein binding
 Factors that effect the transfer of a drug
to the fetus

• Spatial configuration
• Molecule size
• Acid base status of the fetus (all
narcotics
ti are weak kbbases and d will
ill
become concentrated in an acidotic
fetus, or if the mother is alkalotic the
narcotics will be concentrated in the
fetus
 Factors that effect the
transfer of drugs to the fetus
• Uteroplacental
p blood flow ( if
diminished then less drug is delivered
i.e.. PIH, DM as well as hypovolemia
 Narcotics and the fetus
• Fetal metabolism is slower to
metabolize narcotics because of the
immature liver, also the blood brain
barrier is very permeable so the fetuses
are more susceptible to depression
from narcotics.
narcotics
 Narcotics and labor
• N
Narcotics
ti may decrease
d the
th progress
of labor by reducing the force or rate of
contractions ( this is dose dependant
as well as dependant on the timing of
the doses
ggest e
• Biggest effect
ect is
s in tthe
e latent
ate t p
phase
ase
• In the active phase of labor narcotics
may speed up the progress of labor by
decreasing anxiety and decreasing
catecholamines.
catecholamines
 Maternal side effects of
narcotic analgesics
• Arterial and venous dilation because of
histamine release and interference with
baroreceptors
• Orthostatic hypotension can develop
• Usually cardiovascular effects are
minimal unless the pt is hypovolemic
or conduction anesthesia is used
 Maternal side effects of
Narcotic Analgesics
• Nausea and vomiting (increased
smooth muscle tone)) decreased
peristalsis, pyloric sphincter spasm
and delayed gastric emptying
• Respiratory depression (decreased
minute volume)) lower oxygen
saturation and a shift to the right
g of the
CO2 curve causing hypoxia or
hypercarbia, aspiration
 Neonatal side effects of
narcotic analgesia
• Respiratory depression (decreased
minute volume and oxygen
yg saturation
causing a shift of the CO2 dissociation
curve to the right
• Neonates tolerate this much less than
the mother so hypoxia and acidosis
can occur rapidly
p y
 Neonatal side effects of
narcotic analgesics
• The maximal depressive effect from I/M
narcotics is 2-3 hours
• Certain narcotics such as Morphine or
Alaphaprodine have 10 times the
respiratory depressant actions when
compared to Pethidine.
 Neuro-behavioral effects of
narcotics
• Apgar scores will reflect major depressant
effects but there are specific tests to assess
neural behavior of infants who were given
narcotics in labor
• Evaluation consists of neonatal muscle tone,
y to alter their state of arousal, reflexes,
ability
and reactions to repetitive stimuli
 Neonatal effects of narcotic
analgesics
• Some studies have shown behavior
changes
g up p to 4 days
y p post delivery
y
• Suck less effectively
• Depressed
D d visual
i l andd auditory
dit
attention
• Decreased reflexes.
• Take
T k llonger to
t habituate
h bit t to t noise
i
• Decrease social responsiveness
p
 Management of Depressed
neonate
• Naloxone 0.2cc IM to the fetus (not the
mother)) (0.01-0.02mg/kg)
( g g)
• Repeat in 3-5 minutes
• Naloxone
N l competitively
titi l displaces
di l the
th
narcotic molecule from its receptor
• Watch infant for 1 hour after naloxone
is given
 Pethidine
• IV –onset 5-10 min , Lasts upto 3-4 hours
• IM upp to 100mg-onset
g at 40-50 min
• Quick placental transfer
• ½ life 3 hours in mother (up to 23 hrs in
fetus)
• Metabolized to normeperidine
• Neonates born within 2 hours of maternal
administration are at grave risk of respiratory
depression.
 Morphine
• IV 20min onset time
• Last 4-6
4 6 hours
• Very high likelihood on neonatal
d
depression
i
• Not
ot used for
o pain
pa relief
e e in Labor
abo
• Used for sedation in latent phase
• 10-15mg IM
 Patient Controlled Analgesia (PCA) in
labour
Established technology
gy
No ideal drug
Restricted
Epidural contraindicated
F t l non-viability
Fetal i bilit
 Remifentanil
• Ultra-short acting μ agonist
• Novel metabolism
• Rapid offset
• Context sensitive t1/2 ≈ 3mins
• Non-cumulative
• Bolus effect peak 2.5min
Remifentanil
 Inhalational Analgesia
• Entonox – most commonly used
• Typically used at beginning of each
uterine contraction, mother uses the
hand held device and self administer
the agent.
 Regional anesthesia
• Spinal
• Epidural (5-8ml
(5 8ml of local)
• The pain of uterine contractions and
cervical
i l dilation
dil ti can be
b alleviated
ll i t d by
b
blocking T11 and T12 in the early 1st
stage of labor and T10 and L1 later in
the 1st stage
 Regional anesthesia
• During the 2nd stage of labor pain
comes from the stretching g of the
perineum S2,3,4, this can be blocked by
an epidural block but may inhibit the
pushing effort
• Bupivicaine and Chlorprocaine
C have
become the agents
g of choice for
epidural anesthesia (IV of either can
cause cardiac collapse and death
 Local anesthetics
• All LAs cross the placenta quickly
• Some LAs will be found in the maternal
and fetal blood stream from epidural
and Para cervical anesthesia
Sagittal section of the Spinal cord
depicting the Epidural Space
 Walking Epidural
Prerequisites- 1.Counselling of the patient
2.Prior IV hydration
y
3. One attendent should be present
4 Round the clock FHR monitoring
4.Round
• Continuous monitoring of the FHR and
contractions
• 20 min of close BP monitoring after 1st dose
and after top off doses for 10min
• Placed at L2-3 or L3-4
 Walking Epidural
• Test dose is given
• Slow injection
j of the dose to give
g a more
even anesthetic
• Continuous infusion is preferred over
boluses.
• To rule out motor blockade- Modified Deep
Knee Bend, Step up and down the stool
 Walking Epidural
• First appeared in early 1990s.
• Using bupivacaine 0.0625
0.0625-0.1
0.1 % with
Fentanyl 0.0002% ( 2ug/ml) maximizes
labour pain relief and minimizes side
effect.
• On the flip side, women will sometimes
switch from walking to classic epidural
mid labour.
 Epidural
• Continuous epidural infusion-1/3 less
anesthetic
• Gives better pain relief
• 15mg/hr
15 /h Bupivicaine
B i i i
• Requires
equ es IV pump
pu p but pump
pu p can
ca be
adjusted, has battery back up, is under
positive pressure and has auto shut off
 Adverse effects of Epidural
• Slow the progress of labor as well as
decrease the pushing urge. Avoid boluses
near delivery.
• Increased risk of assisted delivery
y with bolus
epidural.
• Increased incidence of Hypertonic uterus-
due to decreased conc. of circulating ß
agonist and predominance of alpha activity.
activity
Treatment- Subcutaneous Terbutaline and
Intravenous Nitroglycerine
 Adverse effects of Epidural
• Accidental dural puncture – Post dural
Puncture Haedache because of large g
bore needle (incidence 0.5-1%)
• Treatment of PDPH-
PDPH abdominal binder
binder,
IV hydration(3000cc), analgesics,
caffeine,
ff last resort is blood patch
with10-15cc of p patient’s blood
 Contraindications to Epidural
anesthesia-
• Patient refusal
• If continuous monitoring g of the pt
p is not
available
• Infection at or near the epidural site, or
septicemia
• Coagulation abnormalities
• Anatomical abnormalities (Spina bifida etc)
 Relative contraindications of
epidural anesthesia
• Anatomic difficulty
• Late in labor close to delivery
y
• Very early in labor
• Uncooperative pt
• Uncontrolled PIH or ecclampsia
• Uncorrected hypovolemia
• Chronic low back pain
 Comparison of epidural butorphanol with
neostigmine and epidural sufentanyl with
neostigmine for first stage of labor analgesia:
A randomized controlled trial
• Epidural combination of sufentanil with neostigmine
provided better pain relief in terms of the total
duration of analgesia and the reduction in VAS pain
scores at various time points in the initial 30 min of
epidural administration of drugs during the first
stage of labor in parturient when compared to the
epidural combination of butorphanol with
neostigmine.
neostigmine

---------------------------------Anesth Essays Res 2017; 11: 365-71

 Disadvantages of Epidural Analgesia

• Maternal Hypotension
• Inadequate analgesia
analgesia- 15
15-20%
20% cases.
• Motor blockade
 Epidural versus non-epidural or no analgesia in labour.
Anim-Somuah M, M Smyth RMD
RMD, Howell CJ
CJ.

------Cochrane Database of Systematic Reviews 2005 Issue 4. Art. No.: CD000331.

 Maternal/neonatal sedation
P thidi
Pethidine F t
Fentanyl
l R if t il
Remifentanil
Desat. (<95%) 33% 56% 37%
Satisfacion (1
(1-10)
10) 7 73
7.3 81
8.1
APGAR5 9.7 9.6 9.9
NACS 120 mins 37.2 36.7 37.8
Cord BE -7.23 -6.67 -5.41
Epidural 34% 15% 13%

---------------------------------Douma M R et al. Br. J. Anaesth. 2010;104:209-215

 Paracervical block
• G
Good d for
f theth paini off cervical
i l dilation
dil ti phase
h
but no help for the perineum
• Given
Gi att 4:00
4 00 andd88:00
00 o’’ clock
l k as theth cervix
i
reflects onto the vaginal fornices
• 3-5cc
3 5 in i each h site(
it ( always
l aspirate
i t 1st)
• Complications are lacerations, intravascular
i j ti
injection, P
Parametrial
t i l hematoma,
h t abscess,
b
and hypotension
 Fetal complications of
Paracervical block

• 70% of cases-Fetal bradycardia (last 2-

10min)
 Pudendal block
• TTransvaginally
i ll or transperineal
t i l
• Use a needle gguide (Iowa
( trumpet)
p )
• Medial and inferior to the sacrospinous
ligament and ischial spine (aspirate 1st)
• 7-10cc each side of lidocaine1% or
chlorprocaine 2%
• For pelvic outlet manipulations(2nd
stage)
 Complications of Pudendal
blocks
• Systemic toxicity(IV)
• Vaginal laceration
• Vaginal or ischiorectal hematoma
• Retro-psoas or sub-gluteal abscess
Thank you for your time and participation
& Best of Luck for exams..!!