This document discusses various techniques for providing analgesia during labor and childbirth. It begins with a brief history of labor analgesia and then describes both non-pharmacological methods like hypnosis and TENS, as well as pharmacological methods including inhalation analgesia, systemic opioids like fentanyl and remifentanil, and regional techniques like epidurals. It provides details on the mechanisms of action, dosages, benefits and risks of different analgesic options. The goal is to relieve pain during labor while maintaining safety for both the mother and fetus.

1. Obstetrical Analgesia
Co-ordinator:- Dr. Roopesh Kumar (M.D)
Speaker:- Dr. Sushil kr. patel

2. Introduction
• Pregnancy and motherhood is a major milestone in the life of a female which
change her position in the family and the society giving more self confidence and
independence.
• Child birth is a painful process and pain relief during labour has always been
associated with myths and controversies. Several groups of people think that God
has made this process painful and no interference should be done in it However,
from the early days several methods including primitive use of rings, neck less,
distraction, and counter stimulation have been used to relieve labour pain.
• In modern era various non- pharmacological and pharmacological methods are
being practiced for labour analgesia.
• Use of labour analgesia has gained wide spread popularity ever since the three
famous women, Fanny Longfellow wife of famous American poet Henry Wadsworth
Longfellow (1847), Emma Darwin wife of Charles Darwin the eminent Naturalist,
and Queen Victoria wife of Prince Albert (1853) not only accepted but strongly
endorsed the use of analgesia during birth process .
• For labour analgesia, epidural administration of local anaesthetic agents and
systemic (intravenous or intra- muscular) administration of opioids (narcotics) are
the two most frequently employed pharmacologic methods in the United States.
• In developing countries like India national average acceptance of epidural
analgesia for labour pain relief is almost negligible though sporadically few centre
have a comprehensive labour analgesia program .

3. conti.....
• Throughout the history several measures have been used to relieve the labour
pain.
• In the earlier days extract of poppy, mandragora, alcohol were used to facilitate
the delivery without much pain. During last four decades labour analgesia has
undergone extensive research and development to find out a technique which is
safe for both mother and fetus .
History of development of different techniques used in labour analgesia
• 1847 Ether
• 1853 Chloroform
• 1881 Nitrous Oxide
• 1900 Spinal with Cocaine
• 1902 Morphine and Hyoscine
• 1909 Caudal Epidural
• 1930 Sacral Epidural
• 1940 Pethidine
• 1943 Continuous Caudal Epidural
• 1949 Continuous Lumber Epidural
• 1958 Psycho prophylaxis by Lamaze
• 1980 TENS

4. Ideal technique of labour analgesia
• Any drug or technique used in labour analgesia should be simple, safe and must
have high technical success rate. It should be acceptable to mother and allow her
active participation in the labour process.
• These drugs and or techniques should provide complete analgesia throughout the
painful period of labour and must be devoid of any harmful effect on mother and
labour process.
• These should maintain a complete fetal homeostasis without any depressant effect
on fetus.

5. Physiology of Labor Pain
• During the first stage of labor, pain impulses arise primarily from the uterus.
Uterine contractions may result in myometrial ischemia, which ultimately causes
the release of bradykinin, histamine, and serotonin. In addition, stretching and
distention of the lower uterine segment and cervix may stimulate
mechanoreceptors.
• These noxious impulses follow the sensory nerve fibers that accompany
sympathetic nerve endings; they travel through the paracervical region and the
hypogastric plexus to enter the lumbar sympathetic chain.
• These stimuli enter the spinal cord at the T10, T11, T12, and L1 spinal segments.
Parturients describe this pain as dull in nature(visceral) and often poorly
localized.
• With onset of the second stage of labor and stretching of the perineum, somatic
afferent nerve fibers transmit impulses through the pudendal nerve to the spinal
cord at the S2, S3, and S4 levels .

6. Figure 3: Pain pathways in a
parturient.
Figure 4: Dermatomal level of the
lower abdomen, perineal area, hip,
and thighs.

7. Timing for analgesia
• Timing for labour analgesia always has been a point of debate among obstetrician
and anaesthesiologist.
• At present time there are no sufficient data available to determine the exact
timing or indication like degree of cervical dilatation or fetal head descent to
which analgesia should be started.
• American college of Obstetrician and Gynecologists recommends that “when
feasible obstetric practitioner should delay the administration of epidural
analgesia in nulliparous women until the cervical dilatation reaches at least 4-5
cm and other analgesics should be used until that time” .
• Wang et al in a study in 12793 parturients found no difference in duration of
labour or incidence of caesarean deliveries with epidural analgesia given either in
the early (cervical dilatation of 1-4 cm) or late (> 4 cm) stage of labour.

8. Techniques of labour analgesia
Non-pharmacological
1. Psychoprophylaxis
Breathing exercise
Duola
2. Hypnosis
3. TENS
4. Acupuncture and Acupressure
5. Hydro therapy
6. Miscellaneous
Yoga
Music therapy
Pharmacological
1. Inhalation analgesia
N2O:O2 ,
Ether, trilene
Halogenated compounds like
Enflurane, isoflurane, sevoflurane
2.Parenteral analgesia
Opioids: pethidine, pentazocine, fentanyl
Remifentanil, sufentanil , , meperidine , butorphanol
and nalbuphine.
Non-opioid: tramadol
Sedative & tranquiliser: diazepam, midazolam
Ketamine
3. Regional analgesia
Lumbar epidural
Caudal epidural
Spinal analgesia
Combined spinal-epidural
Walking epidural
4. Pudendal nerve block
5. Paracervical block

9. Psycho prophylaxis;
• These methods do not change the intensity of the pain but they do alter the
perception of pain and they reduce maternal suffering.
• Psycho prophylaxis helps women interpret the pain as a normal part of labour so
they do not feel threaten from it and find it easier to cope with it.
• Different methods have different approaches but one of the great advantages of all
is that they include extensive education regarding the normal labour process. By
providing quality education they prepare the mother to deal with it better and
reduce the anxiety of the unknown.
• This avoids the huge emotional stress and negative feelings of failure that some
women are left with when they decide to use medications for pain relief.
Lamaze method- The Lamaze method teaches women to respond positively to the
pain of labor. Mothers are taught to relax during the contraction with the help of a
birth partner, contributing to the process of labor without the use of drugs.
Transcutaneous electrical nerve stimulation (TENS)-
• Electrodes are placed about 2cm over the T10-L1 dermatomes either side of the
spinous processes to provide analgesia for the first stage of labour.
• A second set of electrodes is placed over the S2 – S4 dermatomes for second stage
pain relief. Women can alter the amount of current supplied to the electrodes
providing some degree of control throughout their labour
•

10. TENS.....
• Blockade of pain transmission to the brain through stimulation of A-fibre
transmission and local release of β-endorphins are suggested theories for
TENS analgesia; however there is no evidence that TENS provides more
analgesia than placebo.
• Despite this, TENS has minimal side effects and may be appropriate for
women who have contraindications to other methods of pain relief or
where other methods are not available.

11. Pharmacological
1. Inhalation analgesia
• Inhaled analgesia can be defined as the administration of subanesthetic
concentrations of inhaled anesthetics to relieve pain during labor.
• This pain relief technique should not be confused with inhaled anesthesia that
produces unconsciousness and loss of protective laryngeal reflexes.
• Although inhaled analgesia provides a limited amount of pain relief, it is not
adequate to provide sufficient pain relief for most mothers. It may, however, have a
place as an adjunct to neuraxial techniques or in parturients in whom regional
anesthesia is not possible.
• Inhaled analgesics can be administered either intermittently (during contractions)
or continuously. They can be self-administered, but the patient should have a
health care provider present to ensure an adequate level of consciousness and
proper use of the equipment.
• Although inhaled analgesics continue to be used in parts of Europe as well as
developing countries, they are seldom used for labor analgesia in the United States
and scavenging of gases remains a concern.

12. Conti.....
• N 2 O:O2 Inhalation 50:50
• Trilene Inhalation 0.3%-0.5%
• Enflurane Inhalation 0.3%-1.0%
• Isoflurane Inhalation 0.2%-0.7%
• Sevoflurane Inhalation 0.8%-1.0%
Entonox (50 : 50 N2O/O2 mixture) has been used for many years as both a sole analgesic
and an adjuvant to systemic and regional techniques for labor.
 Associated side effects include dizziness, nausea, dysphoria, and lack of cooperation.
The maximum analgesic effect occurs after 45 to 60 seconds, and it is therefore
important that the parturient use Entonox at the early onset of her contractions and
discontinue its use after the peak of the contraction.
 The lack of scavenging systems in labor rooms may theoretically put staff at risk of
exposure to excessive levels over a prolonged period.
 The administration of nitrous oxide and oxygen in a 50 : 50 combination appears to
have no effect on hepatic, renal, cardiac, or pulmonary functions. A recent meta-
analysis by Kronberg and Thompson concludes that inhaled nitrous oxide relieves labor
pain to a significant degree in most patients but does not provide complete analgesia
for many.
 The analgesic effect of nitrous oxide does also seem to be dose dependent, which
supports its analgesic efficacy during labor.

13. conti.....
• Desflurane , enflurane, and isoflurane have also been used to provide labor
analgesia, but their effectiveness is comparable to that of nitrous oxide.
• More recent studies suggest sevoflurane as an effective labor analgesic. An
inspired concentration of 0.8% appears to be acceptable and effective for labor
analgesia.
• Sevoflurane, when compared with Entonox, provided superior pain relief but with
more intense sedation, without adverse effects and which was acceptable to
mothers.
• use of these volatile analgesics, however, is limited by drowsiness, unpleasant
smell, and high cost. The major risk when using volatile analgesics is accidental
overdose resulting in unconsciousness and loss of protective airway reflexes.

14. 2.Parenteral analgesia
Opioids are the most commonly used class of drugs for systemic medication in
laboring women .
• All opioids have various degrees of side effects, including respiratory depression,
nausea, and vomiting, as well as mental status changes ranging from euphoria to
excessive sedation.
• All opioids cross to the placental circulation freely because of their
physicochemical characteristics, and they may cause respiratory depression in the
newborn. However, when used appropriately, systemic opioids can partially
alleviate labor pain for short periods.
• Other systemic drugs used in the treatment of labor pain include sedative-
tranquilizers and ketamine.
Meperidine-
• In the past, meperidine was the most commonly used systemic analgesic to
ameliorate pain during the first stage of labor.
• It can be administered by IV injection (effective analgesia in 5–10 minutes) or
intramuscularly (peak effect in 40–50 minutes). It was also commonly used for
postoperative pain in the general population

15. Opioid.......
• But with the popularity of its administration, disturbing side effects began to
emerge.
• One of the most serious side effects was the occurrence of seizures both from the
primary drug effect and from its metabolite, normeperidine. .
• In the pregnant patient at risk for seizures—that is, with pregnancy-induced
hypertension or preeclampsia—confusing the picture by the administration of a
drug known to cause seizures complicates patient care.
• Other side effects are nausea and vomiting, dose related depression of ventilation,
orthostatic hypotension, the potential for neonatal depression, and euphoria out of
proportion to the analgesic effect, leading to misuse of the drug.
• Meperidine may also cause transient alterations of the fetal heart rate, such as
decreased beat-to-beat variability and tachycardia. Among other factors, the risk of
neonatal depression is related to the interval from the last drug injection to
delivery.
• The placental transfer of an active metabolite, normeperidine, which has a long
elimination half-life in the neonate (62 hours), has also been implicated in
contributing to neonatal depression and subtle neonatal neurobehavioral
dysfunction. Consequently, the use of meperidine has fallen out of favor as an
analgesic for labor

16. Fentanyl
• Fentanyl is an alternative analgesic option for patients in whom neuraxial anesthesia is
contraindicated.
• Its short half-life makes it suitable for prolonged use in labor, either as an intravenous
bolus or as an analgesic administered by means of a patient-controlled analgesia
delivery system.
• It provides reasonable levels of analgesia with minimal neonatal depression. Although
it is a potent opioid, its use in labor has been limited by side effects and short duration
of action.
• Fentanyl crosses the placenta; one study that evaluated intravenous fentanyl for labor
reported that 4 of 11 fetuses whose mothers received fentanyl for analgesia during
labor required naloxone treatment.
• The usual dose of fentanyl for labor analgesia is 25 to 50 µg intravenously. The peak
effect occurs within 3 to 5 minutes and has a duration of 30 to 60 minutes.
• fentanyl in labor has suggested that mild maternal sedation is apparent after the
administration of 50 or 100 µg. In addition, a transient decrease in FHR variability was
also noted.
• Despite these limitations, several investigators have determined that intravenous
fentanyl is preferable to meperidine as a labor analgesic. Fentanyl offers another
advantage in that it can be administered in nonparenteral modalities, including
subcutaneously, orally, and by patch.

17. Remifentanil
• Remifentanil is an opioid that is rapidly metabolized by serum and tissue
cholinesterases, and consequently, has a short (3-minute), context-sensitive half-
time.
• When used in bolus dosing (0.3–0.8 mcg/kg per bolus), remifentanil has been
found to have an acceptable level of maternal side effects and minimal effect on
the neonate.
• Remifentanil crosses the placenta and appears to be either rapidly metabolized or
redistributed in the neonate.
• Apgar and neurobehavioral scores were good in neonates whose mothers were
given an intravenous infusion of remifentanil, 0.1 mcgkg/ min during cesarean
section delivery under epidural anesthesia.
• When administered by patient-controlled analgesia, remifentanil has been found
to provide better pain relief, equivalent hemodynamic stability, less sedation, and a
lesser degree of oxygen desaturation when compared with meperidine.
• In countries outside the United States, intermittent nitrous oxide has been used
for labor analgesia. When comparing remifentanil with nitrous oxide, remifentanil
was found to provide better pain relief with fewer side effects.

18. Opioid agonists–antagonists - butorphanol and nalbuphine
• butorphanol and nalbuphine, have also been used for obstetric analgesia.
• These drugs have the proposed benefits of a lower incidence of nause, vomiting,
and dysphoria, as well as a “ceiling effect” on depression of ventilation.
• Butorphanol is probably the most popular; unlike meperidine, it is biotransformed
into inactive metabolites and has a ceiling effect on depression of ventilation in
doses exceeding 2 mg.
• A potential disadvantage is a high incidence of maternal sedation. The
recommended dose is 1–2 mg by IV or IM injection.
• Nalbuphine 10 mg IV or IM is an alternative to butorphanol.
Naloxone, a pure opioid antagonist, should not be administered to the mother
shortly before delivery to prevent neonatal ventilatory depression because it
reverses maternal analgesia at a time when it is most needed.
• In some instances, naloxone has been reported to cause maternal pulmonary
edema and even cardiac arrest.
• If necessary, the drug should be given directly to the newborn IM (0.1 mg/kg).

19. Sedative-Tranquilizers
• Sedative-tranquilizers, including barbiturates, phenothiazines, hydroxyzine, and
benzodiazepines, have been used for sedation, anxiolysis, or both during early
labor and before cesarean delivery .
• Although barbiturates such as secobarbital were once popular, they are currently
unfashionable because of antianalgesic effects in the mother and prolonged
depressant effects in the neonate.
• Even with small doses of barbiturates that result in no depression of the Apgar
score, the newborn's attention span may be depressed for more than 4 days.
Promethazine is the most commonly administered phenothiazine in obstetrics. Used
with meperidine, it can be given in doses of 25 to 50 mg to prevent emesis. Its
ability to potentiate the analgesic effects of opioids, however, is in doubt.
Ketamine is an N-methyl-D-aspartate (NMDA) receptor antagonist that produces
dissociative anesthesia and has been used in pregnant patients.
• As a phenylcyclidine derivative, its mechanism of action may be mediated by an
interaction with phencyclidine receptors located in the limbic and corticothalamic
areas of the brain. Some evidence, however, suggests that NMDA antagonism is
central to the effects of ketamine.

20. Sedative-Tranquilizers conti.....
Ketamine- has been used in subanesthetic doses (0.5 to 1 mg/kg or 10 mg every 2
to 5 minutes to a total of 1 mg/kg in 30 minutes) during labor.
• In addition to its use in labor, ketamine in a dose of 25 to 50 µg can be used to
supplement an incomplete neuraxial blockade for cesarean section. Its main
disadvantages are the potential for hypertension and emergence reactions.
• High doses (>2 mg/kg) can produce psychomimetic effects and increased uterine
tone, which may cause low Apgar scores and abnormalities in neonatal muscle
tone.
Benzodiazepines -such as diazepam , lorazepam , and midazolam can be used as
sedatives and anxiolytics in labor. However, these drugs readily cross the
placenta, with elimination half-lives as long as 48 hours for diazepam and upward
of 120 hours for its main metabolite N-desmethyldiazepam.
• The use of these drugs during labor will obviously have no effect on fetal
malformations, but they may be associated with other problems in the neonate,
including sedation, hypotonia, cyanosis, and impaired metabolic responses to
stress.

21. DRUG ROUTE DOSE
Pethidine I'm./i.v. 0.25-0.5mg-kg i.v.
1.0-2.0 mg-kg i.m.
Pentazocine I'm./i.v. 0.5-1.0 mg-kg
Butorphanol i.m./i.v. 1.0-2.0 mg-kg
Fentany i.v./infusion/PCIA 1.0-2.0 µg-kg IV
50-100 µg-hr infusion
20 µg with 5 min lockout PCIA
Remifentanil
Sufentanil
PCIA Bolus/PCIA/PCEA Start with 0,1µg-kg
5.0-7.5 µg as bolus
0.25-0.5 µg-ml in PCEA
Non-opiod
Tramadol
i.m./i.v 1.0-2.0 mg-kg

22. Sedative/tranquiliser
DRUG ROUTE DOSE
Diazepam i.m./i.v. 5.0 -10 mg
Midazolam i.m./i.v. 1.0-2.0 mg
Miscellaneous
Ketamine i.v. 10-15 mg bolus every 3-5
min Up to 75-100 mg

23. Regional Analgesia
• Regional techniques provide excellent analgesia with minimal depressant effects
in mother and fetus.
• The techniques most commonly used for labor anesthesia include central
neuraxial blocks (spinal, epidural, and combined spinal/epidural), paracervical,
and pudendal blocks, and, less frequently, lumbar sympathetic blocks.
• Hypotension resulting from sympathectomy is the most common complication
that occurs with central neuraxial blockade. Therefore, maternal blood pressure
must be monitored at regular intervals, typically a very 2–5 minutes for
approximately 15–20 minutes after the initiation of the block and at routine
intervals thereafter.
• Regional analgesia may be contraindicated in the presence of severe
coagulopathy, acute hypovolemia, or infection at the site of needle insertion.
Chorioamnionitis without sepsis, is not a contraindication to central neuraxial
blockade

24. Patient Evaluation and Preparation
• It is important to assess all patients before placement of a regional block by
obtaining a focused medical and obstetric history, performing a clinical
examination, and evaluating the airway.
• The obstetric plan and fetal well-being should be noted during this preoperative
assessment. Informed consent must be obtained, and the anesthesiologist should
explain the procedure and the potential complications of the technique.
• A full check of emergency equipment should be performed to ensure the
immediate availability of resuscitative drugs and equipment. An intravenous
infusion should be started, and appropriate maternal and fetal monitoring should
be in place before starting the procedure

25. Epidural Analgesia
• Effective analgesia for the first stage of labor is achieved by blocking the T10-Ll
dermatomes with a low concentrations of local anesthetic, often in combination
with a lipid-soluble opioid.
• For the second stage of labor and delivery, because of pain due to vaginal
distention and perineal pressure, the block should be extended to include the
pudendal segments, S2-4 .
• There has been concern that early initiation of epidural analgesia during the latent
phase of labor (2–4 cm cervical dilation) may result in prolongation of the first
stage of labor and a higher incidence of dystocia and cesarean section delivery,
particularly in nulliparous women. Generally speaking, the first stage of labor is not
prolonged by epidural analgesia, provided that aortocaval compression is avoided.
• Chestnut et demonstrated that the incidence of cesarean section delivery was no
different in nulliparous women having epidural analgesia initiated during the latent
phase (at 4 cm dilation) compared with women whose analgesia was initiated
during the active phase.
• Others have shown that epidural analgesia is not associated with an increased
incidence of cesarean section delivery compared with IV patient-controlled
analgesia in nulliparous women.
• However, a prolongation of the second stage of labor has been reported in
nulliparous women, possibly owing to a decrease in expulsive forces or malposition
of the vertex.

26. Epidural Analgesia......
• Thus, with use of epidural analgesia, the American College of Obstetricians
and Gynecologists (ACOG) has defined an abnormally prolonged second stage
of labor as longer than 3 hours in nulliparous and 2 hours in multiparous
women.
• A longer second stage of labor may be minimized by the use of an ultra-dilute
local anesthetic solution in combination with opioid.
• Long-acting amides such as bupivacaine, ropivacaine, and levobupivacaine are
most frequently used because they produce excellent sensory analgesia while
sparing motor function, particularly at the low concentrations used for
epidural analgesia.
• Analgesia for the first stage of labor may be achieved with 5–10 mL of
bupivacaine, ropivacaine, or levobupivacaine (0.125–0.25%) followed by a
continuous infusion (8–12 mL/h) of 0.0625% bupivacaine or levobupivacaine,
or 0.1% ropivacaine. Fentanyl 1–2 mcg/mL or sufentanil 0.3–0.5 mcg/mL may
be added.
• During the actual delivery, the perineum may be blocked with 10 mL of 0.5%
bupivacaine, 1% lidocaine, or, if a rapid effect is required, 2% chloroprocaine in
the semirecumbent position.

27. Epidural Analgesia.......
• There is controversy regarding the need for a test dose when using a dilute
solution of local anesthetic.
• Catheter aspiration alone is not always diagnostic. For that reason, some
authors believe that a test dose should be administered to improve
detection of an intrathecally or intravascularly placed epidural catheter.
• If injected into a blood vessel, 15 mcg epinephrine results in a change in
heart rate of 20–30 bpm with a slight increase in blood pressure within 30
seconds of administration. The duration is approximately 30 seconds. The
anesthesiologist should observe the tachometer during the first minute
after injection to determine whether an accidently intravascular injection
has occurred.
• Other subtle signs of intravascular injection may include a feeling of
apprehension, unease, or palpitations. It is important to fractionate the
total dose of local anesthetic and observe the patient at 1-minute
intervals.

28. Epidural Analgesia.........
• Patient-controlled epidural analgesia is a safe and effective alternative to
conventional bolus or infusion techniques.Maternal acceptance is excellent,
and demands on anesthesia manpower may be reduced.
• Initial analgesia is achieved with bolus doses of local anesthetic. Once the
mother is comfortable, patient-controlled epidural analgesia may then be
started with a maintenance infusion (4–8 mL/h) of local anesthetic
(bupivacaine, levobupivacaine, ropivacaine 0.0625–0.125%) with or without
opioid (fentanyl 1–2 mcg/mL) sufentanil 0.3–0.5 mcg/mL).
• The machine may be programmed to administer an epidural demand bolus of
4 mL with a lockout period of 10 minutes between doses.
• The caudal rather than the lumbar approach may result in a faster onset of
perineal analgesia and therefore may be preferable to the lumbar epidural
approach when an imminent vaginal delivery is anticipated.
• However, caudal analgesia is no longer popular because of occasionally painful
needle placement, a high failure rate, potential contamination at the injection
site, and risks of accidental fetal injection.
• Before caudal injection, a digital rectal examination must be performed to
exclude needle placement in the fetal presenting part. Low spinal “saddle
block” has virtually eliminated the need for caudal anesthesia in modern
practice.

29. Spinal Analgesia
• A single intrathecal injection for labor analgesia has the benefits of a reliable and
rapid onset of neural blockade. However, repeated intrathecal injections may be
required for a long labor, thus increasing the risk of postdural puncture headache.
In addition, motor block may be uncomfortable for some women and may prolong
the second stage of labor.
• Microcatheters were introduced for continuous spinal anesthesia in the 1980s.
They were subsequently withdrawn when found to be associated with neurologic
deficits, possibly related to maldistribution of local anesthetic in the cauda equina
region.
• Fortunately, in a recent multi-institutional study, no cases of neurologic symptoms
occurred after the use of 28-gauge microcatheters for continuous spinal analgesia
in laboring women.
• Spinal anesthesia is also a safe and effective alternative to general anesthesia for
instrumental delivery.

30. Spinal Opioids Alone
• Preservative-free opioids may be given intraspinally as a single injection or
intermittently via an epidural or intrathecal catheter .
• Relatively high doses are required for analgesia during labor when spinal opioids
are used alone.
• The higher doses may be associated with a high risk of side effects, most
importantly respiratory depression. For that reason combinations of local
anesthetics and opioids are most commonly used .
• Pure opioid techniques are therefore most useful for high-risk patients who may
not tolerate the functional sympathectomy associated with spinal or epidural
anesthesia .
• This group includes patients with hypovolemia or significant cardiovascular
disease such as aortic stenosis, tetralogy of Fallot, Eisenmenger's syndrome, or
pulmonary hypertension.
• With the exception of meperidine, which has local anesthetic properties, spinal
opioids alone do not produce motor blockade or maternal hypotension
(sympathectomy). Thus, they do not impair the ability of the parturient to push
the baby out.

31. Disadvantages include less complete analgesia, lack of perineal relaxation, and side
effects such as pruritus, nausea, vomiting, sedation, and respiratory depression . Side
effects may improve with low doses of naloxone (0.1–0.2 mg/h IV)
Intrathecal Opioids-
Agent Intrathecal dose Epidural dose
Morphine 0.25-0.5mg 5mg
meperidine 10-15mg 50-100mg
Fentanyl 12.5-25micro grm 50-150 micro grm
Sufentanil 3-10micro grm 10-20micro grm

32. Combined Spinal Epidural Analgesia(CSE)
• First described in 1937
• This technique has risen in popularity over the last 15 years
• Currently being used for Orthopedic, Urologic, and Gynecologic surgeries and for
providing post-op pain relief
• Gained much favor in Obstetrics for providing ANALGESIA & ANESTHESIA for labor,
delivery or for C-sections.
Techniques-there is two method for CSE
1)TWO-LEVEL Technique-The epidural catheter is inserted FIRST and tested so
placement is confirmed
• Then the spinal is done at one or two interspaces below the level of the epidural
• ADVANTAGE: Able to test Epidural cath prior to spinal injection
• DISADVANTAGE: Trauma and discomfort from multilevel insertion
2)SINGLE LEVEL INSERTION:First used in 1982, the “needle-through-needle” technique
involves inserting an epidural needle at the appropriate interspace then using the
epidural needle as a guide or introducer for the spinal needle
• A small 25 or 27gauge spinal needle can be used since the epidural needle is it’s
guide and the tissue has already been penetrated by the first needle

34. 2)SINGLE LEVEL INSERTION……….
Once your epidural catheter is placed, ANY FLUID aspirated from it must be assessed
to see if it is CSF
1) CSF is warm to the touch if allowed to drip on your forearm
2) CSF will form a precipitate if mixed with an equal volume of Sodium Thiopental
3) ANY injection via the catheter must ONLY BE DONE after careful and diligent test
aspirations, and you need to aspirate every 3-5cc while giving your epidural
doses
ADVANTAGE: Single level insertion associated with less tissue trauma, backache and
associated morbidity
DISADVANTAGE: Inability to be able to adequately test the epidural catheter position
and function with a pre-existing spinal block since the spinal part of the procedure
must go first
CSE NEEDLE- 2 Type needle
1)a modified Tuohy needle with a “Back eye” located at the bend of
the needle, most common one used today .
2) a straight beveled, blunt tipped epidural needle, but there is a
higher incidence of inadvertent dural puncture during placement
since it is NOT rounded like the Tuohy

35. CSE.......
• Combined spinal–epidural analgesia is an ideal analgesic technique for use during
labor. It combines the rapid, reliable onset of profound analgesia resulting from
spinal injection with the flexibility and longer duration of epidural.
• The most common one used today is a modified Tuohy needle with a “Back eye”
located at the bend of the needle.
• Intrathecal injection of fentanyl 10–25 mcg or sufentanil 2.5–5 mcg, alone or in
combination with 1 mL of isobaric bupivacaine 0.25%, produces profound analgesia
lasting for 60–120 minutes with minimal motor block.
• Opioid alone may provide sufficient relief for the early latent phase, but almost
always the addition of bupivacaine is necessary for satisfactory analgesia during
advanced labor.
• An epidural infusion of bupivacaine 0.03–0.0625% with opioid may be started
within 10 minutes of spinal injection. Alternatively, the epidural component may be
activated when necessary.

36. CSE.....
• Women with hemodynamic stability and preserved motor function who do
not require continuous fetal monitoring may ambulate with assistance.
Before ambulation, women should be observed for 30 minutes after
intrathecal or epidural drug administration to assess maternal and fetal well-
being.
• A recent study indicated that early administration of combined spinal–
epidural analgesia to nulliparous women did not increase the cesarean
section delivery rate.
• The most common side effects of intrathecal opioids are pruritus, nausea,
vomiting, and urinary retention. Rostral spread resulting in delayed
respiratory depression is rare with fentanyl and sufentanil and usually occurs
within 30 minutes of injection.
• Transient nonreassuring fetal heart rate patterns may occur because of
uterine hyperstimulation, presumably as a result of a rapid decrease in
maternal catecholamines or because of hypotension after sympatholysis.

39. CSE.....
• fetal bradycardia may occur in the absence of uterine hyperstimulation or
hypotension and is unrelated to uteroplacental insufficiency.
• The incidence of fetal heart rate abnormalities may be greater in
multiparous woman with a rapidly progressing, painful labor. Most studies
have demonstrated that the incidence of emergency cesarean section
delivery is no greater with combined spinal–epidural analgesia than after
conventional epidural analgesia.
• Postdural puncture headache is always a risk after intrathecal injection.
However, the incidence of headache is no greater with combined spinal–
epidural analgesia compared with standard epidural analgesia.

40. CSE.....
• Unintentional intrathecal catheter placement through the dural puncture site
is also rare after use of a 26-gauge spinal needle for combined spinal–epidural
analgesia.
• The potential exists for epidurally administered drug to leak intrathecally
through the dural puncture, particularly if large volumes of drug are rapidly
injected. In fact, epidural drug requirements are approximately 30% less with
combined spinal–epidural analgesia than with standard lumbar epidural
techniques for cesarean section delivery.
• Some clinicians do not advocate the combined spinal–epidural analgesia
technique for labor because of the concern for an “unproven” epidural
catheter that may need to be used emergently for cesarean section delivery.
The patient may have a partial block insufficient for surgery with an epidural
that may or may not work.

41. local anaesthetics used in epidural analgesia in labour pain
relief
Local anaesthetic agents
and Drug Concentration
Initial dose Top up dose
Lignocaine 0.5% 10 ml 3-5 ml
Bupivacaine 0.125% 10 ml 6-12 ml–hr infusion
Ropivacaine 0.2% 10 ml 8ml-hr infusion
Levobupivacaine 0.125% 10 ml 6-12 ml-hr infusion

42. Epinephrine-Containing LA Solutions
• The effect of epinephrine-containing solutions on the course of labor is
somewhat controversial.
• Many clinicians use epinephrine-containing solutions only for intravascular
test doses because of concern that the solutions may slow the progression
of labor or adversely affect the fetus; others use only very dilute
concentrations of epinephrine such as 1:800,000 or 1:400,000.
• Studies comparing these various agents have failed to find any differences
in neonatal Apgar scores, acid–base status, or neurobehavioral
evaluations.

43. Paracervical Block
• Although paracervical block effectively relieves pain during the first stage of labor,
it is now rarely used because of its association with a high incidence of fetal
asphyxia and poor neonatal outcome, particularly with the use of bupivacaine.
• This may be related to uterine artery constriction or increased uterine tone.
• Paracervical block is a useful technique to provide analgesia for uterine curettage.
The technique is very simple and involves a submucosal injection of local
anesthetic at the vaginal fornix near the neural fibers innervating the uterus .
Pudendal Nerve Block
The pudendal nerves are derived from the lower sacral nerve roots (S2-4) and
supply the vaginal vault, perineum, rectum, and sections of the bladder.
• The nerves are easily blocked transvaginally where they loop around the ischial
spines. Local anesthetic, deposited behind each sacrospinous ligament can
provide adequate anesthesia for outlet forceps delivery and episiotomy repair.

44. Paravertebral Lumbar Sympathetic Block
• Paravertebral lumbar sympathetic block is a reasonable alternative when
contraindications exist to central neuraxial techniques.
• Lumbar sympathetic block interrupts the painful transmission of cervical and
uterine impulses during the first stage of labor.
• Although there is less risk of fetal bradycardia with lumbar sympathetic block
comparedwith paracervical blockade, technical difficulties associated with the
performance of the block and risks of intravascular injection have hampered its
routine use.
• Hypotension may also occur with lumbar sympathetic blocks.