spinal anesthesia in parturients for cesarean section.ppt

Spinal Anaesthesia in
Spinal Anaesthesia in
parturient for cs
parturient for cs

INTRODUCTION
• Cesarean section (CS) is the most commonly performed major
surgical procedure worldwide.
• Initially, general anesthesia (GA) was primarily used, leading to
high maternal mortality.
 Anesthesia-related maternal mortality has reduced significantly
due to-Increased use of neuraxial anesthesia for CS.
 Availability of algorithms and airway devices for performing
general anesthesia.
• Maternal mortality following general anesthesia was the
primary motivator for the transition toward greater use of
neuraxial anesthesia, for CS

CAESAREAN SECTION
“It is defined as the birth of an infant through incision
in the abdomen(laparotomy) and
uterus(hysterotomy).”
(derived from the latin word caedere which imply to cut)

INDICATIONS FOR CAESAREAN SECTION
Absolute
Absolute
Maternal
 Cephalo-pelvic Disproportion
 Non progression of labour
Fetal:
 Fetal Distress
 Non-cephalic presentations
 Multiple gestations
Pregnancy Related
 Abruptio Placenta
 Grade 3 or 4 Placenta Praevia
 Cervical obstructive lesions
 Large vulvar condylomata
Relative
Relative
Maternal
 Relative CPD
 Maternal preference
Fetal:
 Twins with first in non
cephalic presentation
Pregnancy Related
 Lesser degrees APH
 Previous Caesarean

COMPLICATIONS OF CESAREAN SECTION
Hemorrhage
• Uterine atony
• Uterine laceration
• Broad ligament hematoma
Infection
• Endometritis
• Wound infection
Post op complications
• Cardiovascular: venous thromboembolism
• Gastrointestinal: ileus, adhesions, injury
• Genitourinary: bladder or ureter injury
• Respiratory: atelectasis , aspiration
Chronic pain
Future risk
• Placenta praevia, placenta accreta, uterine rupture

PAIN PATHWAYS
During Caesarean Section:
 Pain due to Incision – Pfannensteil / Midline
 Pain due to stretching to the skin and
subcutaneous tissues
 Intraperitoneal dissection and manipulation
 Additional somatic pain due to diaphragmatic
stimulation
 Involves dermatomes up to T8 and visceral pain
pathways up to T4 levels
 Implications: Aim is to achieve T4 dermatomal
level

ANAESTHESIA FOR CESAREAN SECTION
Techniques of Anaesthesia:
1. Regional Anaesthesia
• Subarachnoid Block(Spinal)
• Epidural Anaesthesia
• Combined Spinal-Epidural Anaesthesia
2. General anaesthesia
3. Local anaesthesia

Anaesthesia for Cesarean Section…..
Depends on:
• Indication for CS
• Urgency of the procedure
• Maternal and fetal health
• Maternal desires
 If time not a factor RA preferred
 Epidural for Labour Analgesia in-situ Extension
of Block
 RA contraindicated, or Emergency procedure
GA

Classification of Cesarean Section (CS) according to urgency
Categor
y
Label Definition Example
1 Emergenc
y
Immediate threat to
the life of the woman
or fetus.
• Prolonged fetal bradycardia
• Uterine rupture
• Severe APH from placenta
previa
2 Urgent Maternal or fetal
compromise which is
not immediately life-
threatening.
• Failure to progress with
thick meconium with
pathological CTG
• Severe pre-eclampsia with
transverse lie
3 Scheduled Need early delivery
but no maternal or
fetal compromise.
• Failed induction of labor
• Breech in labor
4 Elective At a time to suit the
woman and maternity
• Repeat cesarean section
• HIV positive for elective CS
(CATEGORISING URGENCY)

DECISION-TO-DELIVERY INTERVAL (DDI)
Sayegh I, Dupuis O, Clement H, Rudigoz R. Evaluating the decision-to-delivery interval in emergency
caesarean sections. European Journal of Obstetrics & Gynecology and Reproductive Biology.
2004;116(1):28-33.
Grace L, Greer RM, Kumar S. Perinatal consequences of a category 1 caesarean section at term. BMJ
open. 2015;5(7):e007248.

CHOICE OF ANAESTHESIA FOR AN EMERGENCY CS

Rapid Sequence Spinal Anaesthesia ( RSSA)

Adverse events associated with general anesthesia
(GA) in obstetric patients:
•Airway complications (Difficult/failed tracheal intubation).
•Pulmonary aspiration.
•Cerebrovascular injury in the setting of severe hypertension.
•Neonatal depression.
•Unintentional intraoperative awareness.
•Higher incidence of venous thromboembolic complications.
•Uterine relaxation from volatile agents, increased bleeding.
•Increased postoperative pain.
Note:- The risk for failed intubation is 8 times greater in pregnant
patients than in non-pregnant patients.

REGIONAL ANAESTHESIA
Definitive benefits over GA, including
 No risk of aspiration
 No risk of failed intubation or ventilation
 Less blood loss
 Less fetal exposure to drugs
 Better neurobehavioral score of fetus at birth
 Analgesia can be extended to postoperative period
 Early skin to skin contact of neonate with
mother(better mother baby bonding)
 Simple and inexpensive procedure.

Contraindications to neuraxial anesthesia for cesarean
section:
• Patient refusal or inability to cooperate.
•Increased ICP secondary to a mass lesion.
•Skin or soft tissue infection at the site of needle placement.
•Systemic sepsis.
•Frank coagulopathy: Increased risk of spinal epidural hematoma (SEH)
•Recent pharmacologic anticoagulation: Increased risk of SHE
•Uncorrected maternal hypovolemia (Eg: Hemorrhage).
• Thrombocytopenia (Relative contraindication):
Platelet count >75000 Low risk of SEH.
Platelet count 50000-75000 Balance risk and benefit ratio.
Platelet count <50000: Neuraxial technique avoided.

 CONSIDERATIONS IN SPINAL ANESTHESIA FOR CS:-
 Physiological changes.
 Pre-op preparations.
 Preloading/ co-loading
 Anti aspiration prophylaxis
 Positioning in RA
 Choice of LA
 Choice of vasopressors
 Complications of RA i.e. Nausea and vomiting, Hypotension,
accidental intravascular injection , PDPH, LA toxicity.

PHYSIOLOGICAL CHANGES IN PREGNANCY
(relevant to SAB)
The curvature of the spinal column in the nonpregnant (top)
and pregnant patient (bottom). The apex of the lumbar lordosis (blue
circle) moves caudad in pregnancy. Additionally, the thoracic kyphosis
is reduced and shifts cephalad.
• ANATOMICAL CHANGES

 Pelvic widening & resultant head down tilt

• AORTOCAVAL COMPRESSION
Compression of the aorta and inferior vena cava in the supine (left)
and lateral tilt (right) positions.
• Aortocaval compression:Supine position at term gestation leads to
near complete IVC obstruction and partial compression of aorta.
• ↓Preload and ↑ Afterload causes decrease in SV and CO (10-20%)
• ↓uterine blood flow (20%)
• Left lateral position at term gestation: Partial IVC compression.*
venous return maintained by collaterals.

• CARDIAC OUTPUT:
Parameter Begin
s
First T Second T Thirds T
Increase in
HR
4-5 wk 15-25% No
change
No
change
Increase in
SV
20% 25-30% No
change
Increase CO 5
week
35-40% 50% No
change
CARDIAC OUTPUT DURING PREGNANCY:
1st
stage
labour
2nd
stage
labour
Immediate
Postpartum
CO 75% 90% 150%
• It takes 12-24 weeks for CO to drop to pre-pregnancy values.
• During labor, uterine contractions displace 300 to 500 mL of
blood from the intervillous space through the ovarian venous
outflow system into the central circulation (“autotransfusion”).

• Pre-op preparation
 History and physical examination, airway and spine examination.
 Fasting status:
-Clear liquids (Eg: Water, fruit juices without pulp, carbonated beverages) up to
2 hours before induction of anesthesia.
-Fasting period for solids of upto 6 to 8 hrs depending on the type of food
ingested (Fat content).
 Informed consent.
 Blood type or cross-matching.
-CS is associated with >500 ml blood loss. Assure blood availability in blood
bank.
-Assess the patient for risk factors of PPH like anemia, twins, adherent placenta
previa etc.

• Anti aspiration prophylaxis
Increased risk of Gastric Aspiration in pregnancy
- ↓ gastric motility
- ↓ LES tone
- ↑ gastric emptying time.
- ↑ Intragastric pressure

Antiaspiration Prophylaxis:
Planned CS:
 Tab. Ranitidine 150 mg and Metoclopramide 10 mg PO
night before and 60-90 minutes before surgery
Emergency CS :
• 0.3M Sodium Citrate, 30mL PO 30 Min before Surgery.
• Ranitidine 50 mg IV + Metoclopramide, 10 mg IV prior to
surgery.

 Anesthesia machine and monitor check.
 Preparation of airway equipment.
 Check medication availability (Anesthetics, vasopressors,
uterotonics).
 Prophylactic antibiotics:According to 2018 ACOG guidelines,
prophylactic antibiotics within 30 min before incision to reduce the
incidence of post-op endometritis, wound infection and total
maternal infectious morbidity.
 Antibiotics with efficacy against gram +ve, & -ve and some
anaerobie bacteria are commonly used for prophylaxis.
 Intravenous access: Wide bore IV cannula 16 or 18G.

• PRELOADING /CO-LOADING
 Preloading- rapid adminisration of crystalloids (1-
1.5l) prior to initiation of intrathecal injection.
 Co-loading- rapid administration of crystalloids(15-20
ml/kg) initiated at the time of intrathecal injection.
 Crystalloids/ colloids
Implication – Initiation of anaesthesia should not be delayed in
order to administer a fixed volume of fluid.

• Supplemental oxygen
-Preoxygenation before GA.
-Maternal O2 delivery of high Fio (>0.6) may be of benefit
in emergency delivery of compromised fetus.
-Routine administration of supplemental O2 during
elective CS with neuraxial anesthesia of unclear
benefit.

• POSITIONS FOR RA
Lateral position
• better uteroplacental
blood flow.
• more comfortable.
• minimizes patient
movement during
needle insertion.
Sitting position
• Distance from skin to
epidural space is
shorter.
• Restricted use : i.e.in
umbilical cord prolapse,
footling presentation.

POSITIONING IN RA Cont…..
 Minimum left lateral tilt of 25º
 left lateral displacement to be maintained with a
wedge under the right buttock .
1o cm
34 cm
2.5
cm

Spinal anesthesia for CS
•Most commonly used.
•Rapid onset of dense neuroblockade.
•Technically easier.
•Cost-effective.
•Negligible risk of local systemic anaesthetic toxicity (LAST).
•Minimal drug transfer to fetus.
•Safe to administer in pre-eclampsia.
•Use of pencil-point spinal needles (25 & or smaller) instead of
cutting-bevel spinal needles is recommended to minimize the risk of
PDPH.
•Reduced dose of intrathecal local anesthetic.
•Hyperbaric bupivacaine 10-15 mg most commonly used.
•Intrathecal fentanyl added to improve quality of anesthesia.
•Intrathecal morphine for post-operative analgesia.

Anaesthetic blockade:
Sensory block of T4 to sacral dermatomes.
The absence of light touch sensation at the T6 level indicates an
adequate block to proceed without pain or discomfort in most
cases.
Dense motor block of lumbosacral plexus (Assessed by straight
leg raise test).

DECREASE IN LOCAL ANAESTHETIC
REQUIREMENT DURING PREGNANCY
1.↑ Neural susceptibility to LA
2. Epidural plexus engorgement.
3. CSF changes a)↓CSF protein (↑unbound drug)
b)↑ CSF pH (↑ unionised drug)
4. Apex of thoracic kyphosis higher.
5.Pelvic widening & resultant head down tilt in lateral position.

LA (Local
Anesthetic)
Dose Range Duration Comments
Bupivacaine 7.5–15 mg 60–120 min Most common.
Ropivacaine 15–25 mg 60–120 min Not approved
by US FDA for
intrathecal
use.
Levobupivaca
ine
7.5–15 mg 60–120 min
Lidocaine 60–80 mg 45–75 min Transient
neurological
symptoms.
Drugs used for Spinal Anesthesia for Cesarean Section (CS)
Local Anesthetics (LA)

Adjuvant agents
ADVANTAGES
 Improves the quality of intraoperative
anaesthesia
 Prolongs the postoperative analgesia
 Reduce the dose of LA and thus the side effects.

Adjuvant Dose Range Duration Comments
Fentanyl 10–25 mcg 180–240 min Reduces LA dose.
Improves quality of
intra-op anesthesia.
Sufentanil 2.5–5 mcg 180–240 min Prolongs duration.
Morphine 100–200 mcg 720–1440
min (12–24
h)
Prolonged post-
cesarean analgesia.
Hydromorpho
ne
60–75 mcg 720–875 min
(12–14 h)
Epinephrine 100–200 mcg Prolongs LA
duration by
15–20 min
Increases block
density. Improves
quality of analgesia.
Clonidine 60-150mcg Improves intra-op
analgesia,
Hypotension

Complications of neuraxial anesthesia
Hypotension.
Failure of neuraxial blockade.
High block or total spinal
Nausea and vomiting
Pruritis.
Hypothermia and shivering.

HYPOTENSION
• Most common sequela of neuraxial anesthesia.
• Neuraxial anesthesia----- sympathetic blockade---- vasodilation with
modest degree of venodilation → decrease in SVR
• Leads to compensatory increase in HR and SV------Cardiac output
increases. (Secondary response).
• Systolic blood pressure <100 mmHg or fall of 20% from baseline).
• Consequences of hypotension:
-Nausea and vomiting.
-Dizziness, decreased level of consciousness
-Impairment of uteroplacental perfusion with fetal hypoxia and acidosis.

Prevention & treatment of hypotension:
•Left uterine displacement (15 degree tilt recommended): By providing
table tilt or wedge under right hip.
•Leg elevation or compression (Helpful in low resource setting).
•Intravenous fluid (No evidence based recommendation):
Crystalloid preload has no benefit over crystalloid co-load.
Colloid preload is more effective than crystalloid preload.
Colloid preload & co-load are more effective than crystalloid co-load.
Colloids are high cost and potential adverse effects, hence not used
routinely.
Consider crystalloid co-loading.

Vasopressors for Spinal Hypotension
Ephedrine Mephentermin
e
Phenylephr
i-ne (PE)
Noradr Metaraminol
Receptor β1, β2,
weak α
α1, β α1 α1, β α1, weak β
Mechanis
m
Indirect,
weak
direct
Direct, indirect Direct Direct Direct,
indirect
Bolus dose 5–10 mg 6 mg 50–100 mcg 5–6 mcg 0.5–1 mg
Onset Slow Immediate Immediate Immediate 1–2 min

CHOICE OF VASOPRESSORS
 Ephedrine:
• mixed alpha and beta adrenergic receptor agonist
• Increase blood pressure without a decrease in uterine blood
flow
DOSE – 10 mg prophylaxis
5- 10 mg therapeutic
S/E
• Tachyphylaxis
• Can lower umbilical cord pH by
1.Readily cross placenta cause fetal tachycardia
2. Stimulate fetal metabolism by direct b-adrenergic effect
• maternal tachycardia

 Phenylephrine
Animal Studies Clinical Studies
Ephedrine (β1 + β2
agonist, mild α
agonist)
Uteroplacental blood
flow: maintained
Umbilical arterial
blood pH & base
excess: decreased
Crosses placenta Stimulates fetal
metabolism
Phenylephrine
(Pure α1 agonist)
Uteroplacental blood
flow: decreased
Umbilical arterial
blood pH & base
excess: maintained
Less placental
transfer

 Prophylactic Pe infusion:
-Start @25-50 mcg/min.
-Titrated as per BP & HR of the parturient.
-IV boluses: 50-100 mcg.
 Phenylephrine (PE) (Pure alpha-1 agonist) → Known to
cause dose-related transient reflex bradycardia & decreased
cardiac output.
Phenylephrine……..(cont..)

Norepinephrine (NE)
Mild beta1+alpha1 agonist action: Less bradycardia and less
CO.
Prophylactic NE infusion:
5 mcg/mlStart @30 ml/hr.Titrated 0-60 ml/hr.
Iv boluses: 5-6 mcg/mlNe infusion is as effective as
phenylephrine in maintaining BP.
Bradycardia is less likely.
Effects on fetal transfer & metabolic effects is also not clear

Best management of spinal hypotension:
Measure accurate baseline systolic arterial pressure (SAP).
Calculate values for 80% & 90% of baseline SAP.
A prophylactic infusion of phenylephrine should be started immediately after
injection of the spinal anesthetic.
Starting rate at 15-30 ml/h of 100 mcg/ml concentration (25-50 mcg/ min).Can be
titrated by 5-10 ml/h in response to hypotension/hypertension.If SAP < 80%, then
100 mcg rescue boluses should be given.
Use LUD with at least 15 degree pelvic tilt and a free-flowing crystalloid co-load
(15 ml/kg or 1000 ml) immediately after spinal injection.
Measure BP every 1-2 min after spinal injection.
Maintain BP near baseline. Avoid a decrease to <80% baseline.

 Hypotension combined with a low HR should be treated with ephedrine 3-6
mg if SAP <90%
 For hypotension with bradycardia (SAP <80% baseline & HR <60
beats/min), an anticholinergic drug (Glycopyrrolate or atropine) may be
required.
 After delivery, the phenylephrine may be weaned rapidly over
approximately 5 min. Oxytocin & carbetocin may precipitate further
hypotension.
 In resource-limited environments, boluses of phenylephrine (50-100 mcg),
ephedrine (10 mg), metaraminol (0.5 mg), or adrenaline (10 mg) are
recommended to keep SAP >90% baseline & HR <120% baseline.
CONT…

 Failure of neuraxial blockade
 Neuroblockade insufficient in extent, density, or duration to provide
anesthesia for CS.
 Causes of failure:
 Inadequate dose.
 Wrong drug.
 Misplaced injectate.
 Faulty technique.
 Blocked needle.
 Inappropriate positioning.
 Anatomical deformities.
 Kyphosis/scoliosis.
 Obesity

After skin incision:
Iv fentanyl boluses (25-50 mcg).
IV ketamine 5-10 mg boluses.
Inhaled NO (40-50% in oxygen).
General anesthesia.Wound infiltration with LA.
Reassurance, communication & documentation.
Avoid excessive sedation.
Accept failure.
Reassurance.
Communication.
Documentation.

Regional Anaesthesia – Complications
High Spinal Anaesthesia:
 Rostral spread of intrathecal dose, or Inadvertent
intrathecal administration of epidural dose.
 Clinical Features:
 Complete motor and sensory palsy,
 Hypotension, Bradycardia,
 Unconsciousness,
 Loss of protective airway reflexes,
 respiratory arrest
 Treatment: Prompt tracheal intubation and ventilation
with 100% oxygen, maintenance of maternal circulation

 NAUSEA AND VOMITING
CAUSES –
1.Hypotension
hypotension
Gut ischemia brain stem hypoperfusion
Release of emetogenic Stimulation of vomiting
Substance Centre
Vomiting

Perioperative Nausea and Vomiting
Intraoperative Nausea & Vomiting
Anesthetic causes - Hypotension
- Increased vagal activity
Non-anesthetic causes - Surgical stimulation:
• Exteriorization of uterus
• Intra-abdominal manipulation
• Peritoneal traction
- Bleeding
- Uterotonic agents
- Antibiotics

 Postoperative Nausea and Vomiting
Risk Factor Type Associated Factors
GA related risk factors - Female sex
- H/o motion sickness &
PONV
- Non-smoking status
- Peri-operative opioids
SAB related risk factors - Block height T5 or higher
- H/o motion sickness
- Hypotension
- Omission of neuraxial
opioids

Prophylaxis & treatment of nausea and vomiting:
Hypotension is the m/c cause of nausea and vomiting.
Manage hypotension first.
Drug Class Drug Dose Comments
Serotonin
antagonists
Ondansetron 4 mg IV More effective than
metoclopramide in
reducing post-op
nausea.
Granisetron 40 mcg/kg IV After umbilical cord
clamping.
Dopamine receptor
antagonist
Metoclopramide 10 mg IV Before surgery or
after umbilical cord
clamping.
Dexamethasone 4–8 mg IV Reduces PONV after
neuraxial morphine.
Butyrophenone Droperidol 0.625–1.25 mg IV Black-box warning
by FDA on
prolongation of QTc
interval.
Antihistamine Dimenhydrinate 25–50 mg IV

 Most common side effect after intrathecal & epidural opioids.
 Higher incidence and severity after intrathecal opioids.
 Mediated through central µ-opioid receptors, unrelated to histamine
release. Generalized or localized to nose, face and chest.
 Dose dependent, self-limiting.
 Prophylaxis: 5-HT3 receptor antagonist (Ondansetron 4-8 mg)
 PRURITIS

 Management of Pruritis in Women Undergoing CS
Drug Class Drug Dose Comments
Opioid
antagonists
Naloxone 40–80 mcg IV
bolus
1–2 mcg/kg/h
IV infusion
May reverse
analgesia.
Naltrexone 6–9 mg PO
Opioid
agonist-
antagonists
Nalbuphine 2.5–5 mg IV Less likely to
reverse
analgesia.
Propofol 10–20 mg IV Conflicting
evidence.
Ondansetron 0.1 mg/kg IV Conflicting
evidence.
Droperidol 1.25 mg IV Prolongation of
QTc interval.

 Post Dural Puncture Headache
Risk factors:
• Age<40
• Women
• Pregnancy
• Use of wider guage and dura cutting spinal needle.
Symptoms:
• Frontal / Occipital headache
• Positional
• Varying severity
• Neck Stiffness
• Onset within 48 hours

Regional Anaesthesia-Complications
PDPH
Pathophysiology
Treatment:
Early: Psychological support
prevent dehydration
Drugs: NSAIDs, Caffeine, Sumatriptan
Epidural Saline Patch
Epidural Blood Patch-15-20 mL autologous blood used.
Leakage of CSF Traction on pain sensitive structures

 Hypothermia and shivering
 Common after neuraxial anesthesia.
 Vasodilation-induced core-to-periphery heat redistribution.
 Impairment of centrally mediated thermoregulatory contral.
 Peri-operative adverse outcomes :Wound infection.Coagulopathy.Increased
blood loss.Increased O2 consumption, prolonged recovery.
 Prevention & treatment:
 Forced air warming.
 Increase OT temperature from 20° C to 23° с.
 Pethidine 12.5-25 mg IV: most effective.
 Clonidine 150 mcg.
 Dexmedetomidine 0.5 mcg/kg.} concerns regarding hypotension and
sedation

SPINAL ANESTHESIA FOR LSCS IN SPECIAL DISEASE CONDITIONS
 Pre-eclampsia
 Major concerns:- Hypertension and Thrombocytopenia
Thrombocytopenia:
Spinal/epidural anaesthsia causes bleeding or spinal epidural hematoma.
Risk of failed intubation during GA for C-section : I in 443.
Failed intubation in obstetrics is 8 times higher than non-obstetric patients.
Incidence of spinal Epidural Hematoma (SEH) in general population: very low.
Incidence of SEH in Obstetric patients: Lower than non-obstetric patients.
Incidence of epidural hematoma after neuraxial techniques in Obstetrics: 1 in
2,00,000 to 1 in 2,50,000.

Platelet transfusion:
No evidence to assess correct platelet transfusion threshold prior to
neuraxial techniques.
Consider risks of platelet transfusion.
ACOG recommends platelet transfusion in preeclampsia for active
bleeding or to improve the platelet count to 50,000 x 106/L before
Cesarean delivery.

Safe practice in thrombocytopenia:
Consider trend of thrombocytopenia, rather than just a number.
Rule out coagulopathy .
With platelet counts <70000, make an individual decision based on risks
and benefits of neuraxial vs GA.
 A single-shot spinal technique may be preferable to an epidural technique
because of the smaller needle size.
The most skilled anesthesia, provider should perform the neuraxial
procedure.
Check platelet count for evidence of a return toward normal measurements
before removal of the epidural catheter.
Monitor the patient after delivery for neurological signs suggestive of SHE.

Hypertension:
Historical belief:-
Spinal anesthesia in patients with severe preeclampsia causes severe hypo-
tension and decreased uteroplacental perfusion.
Prevented widespread use of spinal anesthesia and favored general anes-
thesia in Pre-eclampsia.
Current evidence suggests:-
Parturients with severe pre-eclampsia experience less frequent, less severe
hypotension than healthy parturients.
Require smaller doses of vasopressors than normotensives.
Spinal anesthesia, can be safely given in severe preeclampsia for Cesarean
delivery.

Challenges:
Poorly controlled hypertension and seizures.
Hypertensive response to laryngoscopy.
Raised intracranial pressure.
Airway edema/tongue bite.
Bleeding :-Thrombocytopenia/coagulopathy.
Depleted intravascular volume.
Risk of pulmonary edema and end organ dysfunction.
Drug interaction with magnesium sulfate:- uterine atony, increased risk of
PPH, prolong neuromuscular block.
 SPINAL ANESTHESIA FOR LSCS IN
ECLAMPSIA

Choice of anaesthesia in patient with Eclampsia:
Fully conscious, alert, seizure free: Neuraxial anesthesia.
Persistent coma, localizing signs,seizures, s/o raised ICP:
General anesthesia.
Considerations for neuraxial anaesthesia:-
Thrombocytopenia/coagulopathy:- platelet >70,000, no
coagulopathy, no bleeding Go for spinal.
Hypotension not a concern.
Judicious use of fluids.
vasopressors to be used to prevent hypotension.

SPINAL ANESTHESIA FOR LSCS IN ANTEPARTUM HAEMORRHAGE
 PLACENTA PREVIA AND PLACENTAL ABRUPTION
Anaesthetic management:
Choice of technique depends on:
Indication/urgency of delivery: Elective/emergency caesarian/acute fetal
distress.
Severity of maternal hypovolemia: Bleeding/shock/stable.
Obstetric history: H/o previous caesarian delivery.
1. Emergency CS/placenta previa with active bleeding:
General anesthesia preferred.

2. For elective CS/placenta previa without bleeding:
Neuraxial techniques is safe:
Combined spinal epidural/Epidural to allow extension for unexpected
cesarean hysterectomy.
Plan in place to convert to general anaesthesia in case of massive PPH.
Preparations:
Wide bore IV cannula kept ready.
Resuscitative measures and blood loss.
Warm IV fluids.
Uterotonics.
Cross matched blood.
Consent for general anaesthesia.
Aspiration prophylaxis.

Pathophysiology of MS in pregnancy:
Stenosed mitral valve → Inadequate left ventricular filling → Reduced stroke volume
→ Compensatory increase in HR → Decreased diastolic filling time →Further
reduction in LV filling and stroke volume..
 SPINAL ANESTHESIA FOR LSCS IN PARTURIENTS WITH MS

vi. Prevent/monitor for pulmonary edema:
Careful fluid balance.
Continuous pulse oximetry throughout labor & postpartum.
Recognize & treat hypertensive disorders of pregnancy.
vii Manage pulmonary edema:
Consider diuresis.
Administer supplemental oxygen.
Labor in upright position.
If necessary, consider intubation & controlled ventilation with PEEP.
Viii. Postpartum monitoring: monitor for postpartum pulmonary edema.

Predelivery planning & preparation:
Summarize cardiac, obstetric and anesthesia history & risk factors.
Have a clear plan of management.
Risk stratification according to mWHO criteria.
Optimize anticoagulation regime to facilitate neuraxial techniques.
Multidisciplinary planning of labor & delivery by the pregnancy heart team.
Determine delivery plan between 20-30 weeks of gestation:
Timing (Induction vs spontaneous labor).
Mode of delivery (vaginal/operative).
Delivery location.
Possible need for cardiac monitoring.
Postpartum plans for monitoring.

Anesthesia for cesarean delivery in MS:
Neuraxial anesthesia: Preferred technique.
Epidural/sequential CSE.
Prophylactic phenylephrine infusion: Start at 25 mcg/min infusion.
Postpartum management:
Highest risk period for cardiovascular disease worsening and
decompensation.
Monitoring in special care unit (Icu/ccu) for patients with severe MS.
More intense monitoring (5-lead ECG, continuous pulse oximeter).
Monitor for arrythmias.
Monitor for pulmonary edema.
Single dose of IV furosemide 20-40 mg within few hours after delivery.
Titrate oxytocin on an infusion pump.
Monitor for PPH and treat rapidly.
Anticoagulation may be needed.

 Cardiopulmonary Effects of Uterotonics
Uterotonic Cardiopulmona
ry Effects
Contraindication
s
Comments
Oxytocin ↓ SVR, MAP,
↓
Tachycardia
Most cardiac
patients tolerate
oxytocin if
carefully titrated
Administer slowly
via infusion
pump. Counteract
MAP with
↓
phenylephrine
infusion. No IV
bolus in patients
with cardiac
disease.
Misoprostol None None Less effective.
Methylergometrin
e
↑ SVR (HTN,
stroke, coronary
vasospasm)
Hypertension,
Pre-eclampsia,
CAD, Aneurysm
Severe
hypertension
when given IV,
which is not
recommended.
Carboprost ↑ PAP,
bronchospasm
Bronchial asthma,
Pulmonary HTN,
RV dysfunction
Contraindicated
IV.

References:
Chestnut DH, Wong CA, Tsen LC, et al. Chestnut’s Obstetric
Anesthesia: Principles and Practice. 6th ed. Philadelphia:
Elsevier; 2020.
Miller RD, et al. Miller’s Anesthesia. 9th ed. Philadelphia:
Elsevier; 2020.
ISA Kerala Online Classes. Anaesthesia for Cesarean Section:
Safe Practices [online lecture]. Indian Society of
Anaesthesiologists, Kerala State Chapter; [Accessed 2022 sep
12]

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