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1. OBSTETRICAL
ANESTHESIA

2. DR. JOHN SNOW
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born 15 March 1813 in York,
England.Queen Victoria was given
chloroform by John Snow for the birth
of her eighth child and this did much to
popularize the use of pain relief in
labor.

3. WHY HAVE A CAREGIVER DEDICATED
TO PAIN MANAGEMENT DURING
LABOR AND DELIVERY?
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4. • Labor and delivery result in severe pain for most women.
• In an attempt to quantify this pain, parturients were asked to rate their
pain during labor.
• These results were then compared to values obtained from patients
in a general pain clinic and emergency department.
• The pain of childbirth was greater than a fractured arm and cancer
pain.
• Only causalgia and amputation of a digit exceeded the pain of labor
and delivery.
• Parturients described the pain as sharp, cramping, aching, throbbing,
stabbing, hot, shooting, and tight.
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5. WHAT IS THE CAUSE OF LABOR
PAIN IN STAGE 1? WHAT TYPE OF
PAIN IS IT?
• The pain resulting from the first stage of labor
is primarily due to dilatation of the cervix with
consequent distention and stretching.
• As the uterus contracts, the fetal head pushes
against the cervix and causes dilatation.
• Therefore, stage 1 pain generally occurs only
during uterine contraction.
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6. • While the majority of pain during this stage
occurs from the fetal head pushing against
the cervix, there is also pain from pressure
and stretching of the uterine muscles, which
activate the high-threshold
mechanoreceptors.
• In the first stage of labor, the pain is visceral.
• It is strong and dull, and occurs over the
lower abdomen between the umbilicus and
the symphysis pubis, laterally over the iliac
crest, and posteriorly in the skin and soft
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7. • Second-stage pain occurs as the fetus descends
through the birth canal.
• This results in stretching and tearing of fascia,
skin, and subcutaneous tissue.
• This somatic pain is transmitted primarily through
the pudendal nerve.
• The pudendal nerve is derived from the anterior
primary divisions of sacral nerves, S2 S3 and S4.
• Of note, the fetus often begins to descend during
the first stage of labor.
• During the transitional stage of the first stage, it is
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8. PAIN PATHWAYS OF LABOR 9/3/2013
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Pathways of labor pain

10. PAIN IS CAUSED BY,
Unpleasant feeling to the mother
Maternal exhaustion – maternal acidosis fetal
acidosis
Catecholamine release
Maternal sympathetic over activity

11. INTRODUCTION
Anesthesia complications caused 1.6 percent of pregnancy-related
maternal deaths
Several factors likely have contributed to improved safety of obstetrical
anesthesia;
the recent trend toward increased use of regional analgesia, rather
than general anesthesia, may be the most significant factor.
The increased availability of in-house anesthesia coverage almost
certainly is another important reason
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12. MATERNAL RISK FACTORS THAT
SHOULD PROMPT ANESTHESIA
CONSULTATION
 Marked obesity
 Severe edema or anatomical abnormalities of face, neck, or spine, including
trauma or surgery
 Abnormal dentition, small mandible, or difficulty opening mouth
 Extremely short stature, short neck, or arthritis of the neck
 Goiter
 Serious maternal medical problems, such as cardiac, pulmonary, or
neurological disease
 Bleeding disorders
 Severe preeclampsia
 Previous history of anesthetic complications
 Obstetrical complications likely to lead to operative delivery—e.g., placenta
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13. GOALS OF LABOUR
ANALGESIA
• Dramatically reduce pain of labor
• Should allow parturient to participate in birthing experience
• Minimal motor block to allow ambulation
• Minimal effects on fetus
• Minimal effects on progress of labor
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14. WHAT ANESTHETIST SHOULD
KNOW
• In order for your anesthetist to determine which type of anesthesia is best for
you and your baby, it is important that you inform your anesthetist about:
• Food and drink intake for the last several hours.
• History of difficulty breathing after anesthesia.
• History of lower back problems.
• Family history of high fevers.
• Any respiratory problems such as asthma, bronchitis, pneumonia, or if you
have a cold, sore throat or flu.
• Special medical concerns such as cardiac disease, diabetes, asthma, and
other medical conditions
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15. TYPES OF LABOR ANALGESIA
1. Non-pharmacological analgesia
2. Pharmacological
3. Regional Anesthesia/Analgesia
4. General Anesthesia
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16. NONPHARMACOLOGICAL METHODS
OF PAIN CONTROL
Fear and the unknown potentiate pain.
Make a woman who is free from fear, and develop confidence in the
obstetrical staff that cares for her
Avoid emotional tension
teaching pregnant women relaxed breathing and their labor partners
psychological support techniques.
Motivatation
the presence of a supportive spouse
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17. ANALGESIA AND SEDATION
DURING LABOR
• When uterine contractions and cervical dilatation cause discomfort, pain
relief with a narcotic such as meperidine, plus one of the tranquilizer
drugs such as promethazine, is usually appropriate.
• With a successful program of analgesia and sedation, the mother should
rest quietly between contractions.
• In this circumstance, discomfort usually is felt at the acme of an effective
uterine contraction, but the pain is generally not unbearable.
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18. NEURAXIAL OPIOIDS
 The following opioids have been used:
 Morphine, fentanyl, sufentanil, meperidine,
diamorphine.
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19. PHARMACOLOGICAL
Opioids
•Pethidine 75mg IM 4-6 hourly (1mg/kg)
•With(antiemetic) promethazine25mg IM
•S/E nausea
vomiting
delayed gastric emptying
respiratory depress(reversed by Naloxon)
maternal drowsiness & sedation
• Morphine also can be used, but S/E more
(Respiratory depress)

20. FENTANYL
This short-acting and potent synthetic opioid
may be given in doses of 50 to 100mcg
intravenously every hour.
Its main disadvantage is a short duration of
action, which requires frequent dosing or the
use of a patient-controlled intravenous pump.
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21. EFFICACY AND SAFETY OF PARENTERAL AGENTS
• Meperidine is the most common opioid used worldwide for pain relief in
labor.
• There is no convincing evidence demonstrating that alternative opioids
are better.
• There is no evidence that parenteral opioids influence the length of labor
or need for obstetrical intervention.
• Epidural analgesia provides superior pain relief.
• Intravenous and intramuscular sedation are not without risks.
 maternal anesthetic-related deaths were from such sedation-aspiration,
inadequate ventilation, and overdosage.
 Moreover, meperidine or other narcotics used during labor may cause newborn
respiratory depression.
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22. INHALATIONAL ANALGESIA
• N2O in the form of Entonox
Quick onset(1-2min), short duration of effect (2-8min
) start inhaling at the onset of a contraction
• Not suitable for prolong use of early labour because
hyperventilation can cause hypocapnoea, dizziness &
ultimately fetal hypoxia

23. REGIONAL ANESTHETIC
TECHNIQUES, WERE
INTRODUCED TO
OBSTETRICS IN 1900,
WHEN OSKAR KREIS
DESCRIBED THE USE OF
SPINAL ANESTHESIA.
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24. REGIONAL ANALGESIA
Various nerve blocks have been developed over the
years to provide pain relief during labor and delivery.
They are correctly referred to as regional analgesics.
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25. REGIONAL
ANESTHESIA/ANALGESIA
• Epidural
• Spinal
• Combined Spinal Epidural (CSE)
• Continuous spinal analgesia
• Paracervical block
• Lumbar sympathetic block
• Pudendal block
• Perineal infiltration
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26. PUDENDAL BLOCK
• This block is a relatively safe and simple method of
providing analgesia for spontaneous delivery.
• The end of the introducer is placed against the
vaginal mucosa just beneath the tip of the ischial
spine.
• The needle is pushed beyond the tip of the director
into the mucosa and a mucosal wheal is made with
1 mL of 1-percent lidocaine solution or an
equivalent dose of another local anesthetic.
• To guard against intravascular infusion, aspiration is
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28. COMPLICATIONS OF PUDENDAL BLOCK
Central Nervous System Toxicity , intravascular injection of a local
anesthetic agent may cause serious systemic toxicity.
Hematoma formation
Rarely, severe infection may originate at the injection site. The
infection may spread posterior to the hip joint, into the gluteal
musculature, or into the retropsoas space.
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29. PARACERVICAL BLOCK
This block usually provides satisfactory pain relief during the first stage
of labor.
Because the pudendal nerves are not blocked, however, additional
analgesia is required for delivery.
Usually lidocaine or chloroprocaine, 5 to 10 mL of a 1-percent solution,
is injected into the cervix laterally at 3 and 9 o'clock.
 Bupivacaine is contraindicated because of an increased risk of
cardiotoxicity.
Because these anesthetics are relatively short acting, paracervical
block may have to be repeated during labor.
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30. COMPLICATIONS OF
PARACERVICAL BLOCK
Fetal bradycardia(15%)
Bradycardia usually develops within 10 minutes and
may last up to 30 minutes.
The effect may be the consequence of transplacental
transfer of the anesthetic agent or its metabolites and
in turn, a depressant effect on the fetal heart.
For these reasons, paracervical block should not be
used in situations of potential fetal compromise.
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31. SPINAL ANESTHESIA/ANALGESIA
• Used mainly for very late in
labor because it has limited
duration of action
• Faster onset than Epidural
• Amount of local anesthetic
used is much smaller
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32. SPINAL ANAESTHESIA
• A fine gauge atraumatic spinal needle is inserted in to the
subarachnoid space
• Small volume of local
anaesthetic is injected, after
which the spinal needle is
withdrawn
• Not used for routine analgesia
in labour
• Combined spinal- epidural analgesia?

33. SPINAL (SUBARACHNOID) BLOCK
• Introduction of a local anesthetic into the subarachnoid space to effect
analgesia has long been used for delivery.
• Advantages include a short procedure time, rapid onset of the block,
and high success rate.
• Because of the smaller subarachnoid space during pregnancy, likely
the consequence of engorgement of the internal vertebral venous
plexus, the same amount of anesthetic agent in the same volume of
solution produces a much higher blockade in parturients than in
nonpregnant women.
• Obstetrical complications that are associated with maternal
hypovolemia and hypotension—such as severe hemorrhage—are
contraindications to the use of spinal block.
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34. EPIDURAL ANALGESIA
 Provides excellent pain relief reducing
maternal catecholamines
 Ability to extend the duration of block
to match the duration of labor
 Blunts hemodynamic effects of uterine
contractions: beneficial for patients
with preeclampsia.
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35. EPIDURAL ANALGESIA
• Epidural catheter inserted at the level of L2-L3
L3-L4 or L4-L5 interspace & to the epidural space.
• Catheter is aspirated to check the position
• Test dose given to confirm the catheter position
small volume of diluted local anaesthetic (10-15ml)
• After 5mins loading dose of mixture of 0.1%
Bupivacaine with fentanyl 12mcg/ml is given
• Prepare ephedrine for IV injection(30mg diluted in 9mg of
saline or water)

36. INDICATIONS FOR LEA
 PAIN EXPERIENCED BY A WOMAN IN
LABOR
 When medically beneficial to reduce the
stress of labor
 ACOG and ASA stated
“ in the absence of a medical
contraindication, maternal request is a
sufficient medical indication for pain
relief…”
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37. IMPORTANT…
• Secure IV access
• Establishment/after each bolus measure BP every 5min for 15min
• Every hour; check level of sensory block.
• Continue until completion of the 3rd stage & any perineal repair.
• Birth should take place within 4hours.

38. CONTRAINDICATIONS
• Coagulation disorders
• Local or systemic sepsis
• Hypovolamia
• Insufficient no.of trained staff

39. COMPLICATIONS
• Accidental dural puncture-leak of CSF causing spinal headache
• Accidental total spinal anaesthesia -severe hypotension, respiratory
failure, unconsciousness & death
• Drug toxicity occur with
accidental placement of catheter
within a blood vessel
• Bladder dysfunction
• Short term respiratory distress in
baby

40. OBSTETRIC CONDITIONS WHERE
EPIDURAL ANALGESIA IS MORE
LIKELY TO BE INDICATED:
• Pre eclampsia/hypertensive disease
• Prolonged labour
• Two or more babies inutero
• Anticipated instrumental delivery
• Diabetes Mellitus
• Breech presentation for vaginal delivery
• Significant respiratory disease
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42. STANDARD TECHNIQUE OF LEA
4. Maternal position ( sitting or lateral?)
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43. COMPARISON OF SITTING AND LATERAL POSITIONS
FOR PERFORMING SPINAL OR EPIDURAL
PROCEDURES
Sitting Lying (left lateral)
Advantages
• Midline easier to identify in obese
women
• Obese patients may find this position
more comfortable
• Can be left unattended without risk of
fainting.
• No orthostatic hypotension
• Uteroplacental blood flow not reduced
(particularly important in the stressed
fetus)
Disadvantages
• Uteroplacental blood flow decreased
• Orthostatic hypotension may occur
• Increased risk of orthostatic
hypotension if Entonox and pethidine
have been administered
• Assistant (or partner) needed to support
patient
• May he more difficult to find the
midline in obese patient
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44. CONT…
• Women receiving prophylactic doses of unfractionated heparin
or low-dose aspirin are not at increased risk and can be offered
regional analgesia.
• For women receiving once-daily low-dose low-molecular-weight
heparin, regional analgesia should not be placed until 12 hours
after the last injection.
• Low-molecular-weight heparin should be withheld for at least 2
hours after the removal of an epidural catheter.
• The safety of regional analgesia in women receiving twice-daily
low-molecular-weight heparin has not been studied sufficiently.
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45. COMBINED SPINAL–EPIDURAL
TECHNIQUES
• may provide rapid and effective analgesia for labor as well as for
cesarean delivery.
• an introducer needle is first placed in the epidural space. A small-
gauge spinal needle is then introduced through the epidural needle
into the subarachnoid space—this is called the needle-through-needle
technique.
• A single bolus of an opioid, sometimes in combination with a local
anesthetic, is injected into the subarachnoid space, the spinal needle
is withdrawn, and an epidural catheter is then placed. The use of a
subarachnoid opioid bolus results in the rapid onset of profound pain
relief with virtually no motor blockade.
• The epidural catheter permits repeated dosing of analgesia.
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46. COMBINED SPINAL EPIDURAL
(CSE)
 Initial reports: two interspace
technique-epidural followed by spinal
 Later evolution of CSE in the direction
of needle through needle technique
 Postdural puncture headache: 1% or
less incidence for CSE with small bore
atraumatic needles.
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47. ADVANTAGES OF CSE FOR LABOR
ANALGESIA
 Rapid onset of intense analgesia (the patient loves
you immediately!)
 Ideal in late or rapidly progressing labor
 Very low failure rate
 Less need for supplemental boluses
 Minimal motor block (“walking epidural”)
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49. PATIENT PREPARATION
• Prior to anesthesia induction, several steps should be
taken to help minimize the risk of complications for the
mother and fetus. These include the
use of antacids,
 lateral uterine
displacement, and
preoxygenation.
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50. INDUCTION OF ANESTHESIA
Thiopental
Ketamine
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51. INTUBATION
• Immediately after the patient is rendered unconscious, a muscle
relaxant is given to facilitate intubation.
• Succinylcholine, a rapid-onset and short-acting agent,
commonly is used.
• Cricoid pressure—the Sellick maneuver—is used to occlude the
esophagus from induction until intubation is completed by a
trained assistant.
• Before the operation begins, proper placement of the
endotracheal tube must be confirmed.
• Such confirmation includes auscultation of bilateral breath
sounds and end-tidal carbon dioxide analysis.
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52. FAILED INTUBATION
Although uncommon, failed intubation is a major cause of anesthesia-
related maternal mortality.
A history of previous difficulties with intubation as well as a careful
assessment of anatomical features of the neck, maxillofacial,
pharyngeal, and laryngeal structures may help predict a difficult
intubation.
Even in cases where the initial assessment of the airway was
uneventful, edema may develop intrapartum and present considerable
difficulties.
 Morbid obesity is also a major risk factor for failed or difficult
intubation.
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53. MANAGEMENT OF FAILED
INTUBATION
 start the operative procedure only after it has
been ascertained that tracheal intubation has
been successful and that adequate ventilation
can be accomplished.
Even with an abnormal fetal heart rate pattern,
initiation of cesarean delivery will only serve to
complicate matters if there is difficult or failed
intubation.
 Frequently, the woman must be allowed to
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54. • Following failed intubation, the woman is ventilated by mask and
cricoid pressure is applied to reduce the chance of aspiration.
• Surgery may proceed with mask ventilation or the woman may be
allowed to awaken.
• In those cases where the woman has been paralyzed, and where
ventilation cannot be reestablished by insertion of an oral airway,
laryngeal mask airway, or use of a fiberoptic laryngoscope to
intubate the trachea, a life-threatening emergency exists.
• To restore ventilation, percutaneous or even open cricothyrotomy is
performed, and jet ventilation begun.
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55. ANESTHESIA FOR CESAREAN
SECTION
• GA associated with higher risk of airway
problems .
• Incidence of failed tracheal intubation in
pregnant women is 1 in 200 to 1 in 300
cases
Anesthesia2000;55:690-4
• Maternal death due to anesthesia is the
sixth leading cause of pregnancy related
death in USA
Obstet Gynecol 1996;88:161-7
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56. ANESTHESIA FOR CESAREAN
SECTION
• The risk of maternal death from
complications of GA is 17 times as high
as that associated with Regional
anesthesia
• In USA the shift from GA to RA for CS
resulted in decrease in anesthesia related
maternal mortality from 4.3 to 1.7 per 1
million live birth Anesthsiology 1997;86:277-84
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57. COMPLICATIONS OF
REGIONAL ANESTHESIA
Post Dural Puncture Headache (PDPH)
 severe, disabling fronto-occipital headache with
radiation to the neck and shoulders.
 present 12 hours or more after the dural puncture
 worsens on sitting and standing
 relieved by lying down and abdominal compression.
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58. COMPLICATIONS OF
REGIONAL ANESTHESIA
PDPH syndrome
1. Photophobia
2. Nausea
3. Vomiting
4. Neck stiffness
5. Tinnitus
6. Diplopia
7. Dizziness
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