This a topic that emphasize general and neuraxial anesthesia for CS

1. ANAESTHESIA FOR
CAESAREAN SECTION
Misganaw M(BSc, MSc
assistant professor)
 mengiemisganaw@rocketmail.com
University of Gondar
College of medicine and health
science
SCHOOL OF MEDICINE
DEPARTMENT OF ANAESTHESIA

2. OUTLINE
 Introduction
 Spinal anesthesia for CS
 Epidural anesthesia
 General anesthesia

3. INTRODUCTION
 Caesarean section (LSCS) is one of the commonest
operations performed in the developing world and is
often carried out in difficult circumstances
 WHO recommends an optimum caesarean section rate
of 5-15% to ensure best outcome for mother and
neonate.

4.  Caesarean section itself is associated with a significant
morbidity and mortality
 and improvements in surgical and anaesthetic
management can reduce this.
 In a prospective study conducted in Latin America which
investigated more than 105,000 deliveries, mothers
delivered by caesarean section were over 2 times more
likely to suffer from severe maternal morbidity compared
with vaginal delivery.

5.  The problems concern 5 areas:
 1. The patients
 2. The surgery (and the surgeon!)
 3. The drugs (both anaesthetic drugs and any
taken by the patient)
 4. Equipment
 5. The anaesthetist

6.  Problems with the patients
 2 paients
Problems with the surgery
Who is the surgeon, how experienced, how long
does he expect to take and what incision is planned?
Problems with drugs
The pregnant woman may be taking drugs for
concurrent diseases which have to be considered, e.g.
steroids, anti diabetic medication.

7.  Problems with equipment
 What anaesthetic equipment is available? Is
there adequate oxygen , either in cylinders or as
a functioning oxygen concentrator? Is the power
supply reliable? Does the sucker work and is
there a back up manually operated sucker?
Does the table tilt and is there a suitable wedge
available?

8.  Problems with the anaesthetist
 Finally, you should consider how experienced you are
with any particular technique.
 Can you obtain the help of another anaesthetist?
 This is a good policy if you are expecting a difficult
intubation or other problems.
 do you have a trained assistant? Do they know how to do
cricoid pressure correctly? Having considered all the
potential difficulties, make a plan for your anaesthetic.

9. Indications for Caesarean Section
• Previous Caesarean Section*
• Malpositions* (Breech)
• Fetal Distress*
• Dystocia (Failure to progress during labour) *
• Maternal Disease
Worsening pre-existing disease (e.g. cardiac)
Associated with pregnancy (e.g. pre-eclampsia)
• Placenta Praevia or abruption
• Multiple Pregnancy
• Cord Prolapse . Maternal Choice

10.  Spinal Anaesthesia for Caesarean Section
 A single shot spinal should reliably produce
adequate anaesthesia within 10-20 minutes of
injection. In obstetrics it may effective with in 5
minute.
 It is the technique of choice for most obstetric
anaesthetists for caesarean section where there is
no existing labour epidural
 It can be used in the elective and in all but the
most urgent of cases where general anaesthesia
may be more appropriate.

11.  Spinal spread is greater in pregnant compared with non-
pregnant women.
 Technique
Patient positioning
 Sitting
 Lateral

12.  needle
 Pencil Point (e.g.Whitacre, Sprotte) o Less likely to
cause PDPH
 Cutting (e.g. Quincke) If used, use smallest possible
gauge and insert cutting edge in saggital plane.
 Gauge , PDPH is related to size of needle – 25G and
27G pencil point commonly used

13. Figure . Aseptic precautions (surgical cap, mask, gown,
gloves, and large sterile drape).

14. Introducer
 Reduces deviation of small gauge spinal needles
 Approach •
Midline
Paramedian
Baricity of local anaesthetic solution
Dose
Barbotage
Speed of injection
volume

15.  Position during and after injection
 Height (extremely short or tall)
 Spinal column anatomy
 Decreased cerebrospinal fluid volume (increased
intra-abdominal pressure due to increased weight,
pregnancy, etc.
 Site of injection
 Needle bevel direction

16. Figure . Spinal needle designs: (A) Whitacre,
(B) Sprotte, (C and D) Quincke (side and front
profiles).

17. Intrathecal opioids
• Intrathecal opioids have a synergistic effect with local
anaesthetic agents and act
• directly on opioid receptors in the spinal cord. They
may:
• Reduce intraoperative discomfort
• Prolong spinal analgesic action
• Provide postoperative analgesia and reduce
postoperative opioid requirements
• What are opioid Complications?

18. Agent Intrathecal
epidural
Morphine 0.25–0.5 mg
5mg
Meperidine 10–25 mg
50-100mg
Fentanyl 12.5–25ug 50-150ug
Sufentanil 3–10 ug 10-20ug

19. Advantages of spinal compared with epidural
anaesthesia for caesarean section
• Quicker to perform
• Produces more reliable block with faster onset
• Less trauma to epidural space
• Avoids epidural catheter related complications
Disadvantages compared with epidural
• Increased risk of hypotension and placentalinsufficiency
• No means of top up if surgery is prolonged

20. ADVANTAGES OF SPINAL ANESTHESIA
 1. Simplicity of technique
2. Speed of induction (in contrast to an epidural
block)
3. Minimal fetal exposure to the drug(s)
4. An awake parturient
5. Minimization of the hazards of aspiration

21.  The Advantages of Spinal Anaesthesia over GA in all
surgical patient
 Cost
 Patient satisfaction
 Respiratory disease
 Patent airway
 Diabetic patients
 Muscle relaxation
 Bleeding
 Coagulation

22. COMPLICATIONS OF SPINAL ANESTHESIA
 Nausea and vomiting
 Hypotension
 Shivering
 Postdural puncture headache
 Total and high spinal anesthesia
 Itch
 Transient mild hearing impairment
 Urinary retention
 Failed spinal

23. COMPLICATIONS OF SPINAL ANESTHESIA
 Direct needle trauma
 Infection (abscess, meningitis)
 Vertebral canal hematoma
 Spinal cord ischemia
 Cauda equina syndrome
 Arachnoiditis

24.  Contraindications for Spinal Anesthesia
for Cesarean Section
 1. Severe maternal bleeding
2. Severe maternal hypotension
3. Coagulation disorders
4. Some forms of neurological disorders
5. Patient refusal
6. Technical problems
7. Short stature and morbidly obese parturients due to the fear
of high spinal block

25.  Failed or Inadequate Spinal Anaesthesia
 The potential aetiology of failure can be
 anatomical
Failure of dural puncture with the spinal needle due to
spinal abnormalities such as kyphosis, scoliosis,
limitation of spinal flexion, or calcified ligaments
Failure of local anaesthetic spread caused by
adhesions or septae in the epidural space (eg
secondary to previous
surgery)

26.  Technique:
 * Loss of drug between the needle hub and syringe, or partial
deposition of the anaesthetic solution in the subdural or
epidural space resulting in an inadequate effect despite
obtaining flow of cerebrospinal fluid in the spinal needle.
 The aperture in the pencil-point needle straddling the dura, or
a dural tag; if there is no (or very slow) flow of cerebrospinal
fluid in the spinal needle, gentle and slight rotation of the
spinal needle may move the dural tag and allow good flow of
cerebrospinal fluid.

27.  Drug error:
 * Incorrect intrathecal drug administration, which can be
disastrous; for example Patel et al identified 21 reported cases of
intrathecal tranexamic acid injection, of which 20 resulted in life-
threatening conditions and 10 were fatal.
 Equipment:
 * Blocked spinal needle, resulting in a dry tap despite the needle
tip entering the subarachnoid space

29. Epidural Anaesthesia for Caesarean Section
Epidural top up is an increasingly popular technique for
providing anaesthesia for caesarean section as a
result of the rising numbers of epidurals inserted for
labour pain relief.
The quality of the block is often inferior to spinal
anaesthesia

30. COMPARISON OF SPINAL &
EPIDURAL ANESTHESIA

31.  Advantages compared with spinal
 • If epidural in-situ, prevents risk of undergoing a
further procedure.
 • Hypotension less pronounced
 • Ability to maintain anaesthesia if prolonged
procedure
 • Option for postoperative analgesia

32.  Disadvantages compared with spinal
 Increases time taken to establish block suitable for
surgery
 Less dense block and possibility of missed segments
and intraoperative
 pain
 Sacral block can be problematic
 Lower extent of block must be documented

33.  Combined Spinal / Epidural (CSE) for Caesarean Section
 Combines advantages (and disadvantages) of both
techniques
 Rapid onset of spinal block
 Ability to modify / top-up / prolong anaesthesia with epidural
component
 Spread of spinal anaesthetic can be increased with injection of
saline into the epidural space (compression effect of dural sac)
 Option for post-op analgesia

34. Able to use lower dose spinal and modify if required
Reduces need for conversion to general anaesthetic in
event of spinal failure
Can produce a denser block than either technique in
isolation

35.  Disadvantages •
 Potential increased risk – two procedures
 Higher failure rate than individual procedures
 Increased time to perform
 CSE kits more expensive
 Theoretical increased risk of meningitis (breached dura
and indwelling catheter)

36. GENERAL ANAESTHESIA FOR
CAESARIAN
 General anaesthesia in the obstetric patient is associated
with an increased risk of morbidity and mortality including
airway difficulties and failed intubation.
 Maternal mortality as a direct result of anaesthesia has
fallen as more caesareans are performed under regional
anaesthesia.
 As a consequence of this trend, trainee anaesthetists are
now more limited in their exposure to general anaesthesia
for caesarean section.

37.  In certain emergent situations (e.g., fetal
bradycardia,maternal hemorrhage or coagulopathy,
uterine rupture, maternal trauma)general anesthesia may
be needed for cesarean delivery because of its rapid and
reliable characteristics.

38. GENERAL ANESTHESIA
 The advantages of general anesthesia are as follows:
1. Speed of induction
2. Reliability
3. Controllability 5. Avoidance of hypotension
The following are disadvantages of general anesthesia:
1. Possibility of maternal aspiration
2. Problems of airway management
3. Narcotization of the newborn
4. Maternal awareness during light general anesthesia

39.  There are significant challenges associated with general
anaesthesia (GA) in the pregnant woman
 Changes in maternal physiology and anatomy present their own
challenges but can also exacerbate pre-existing medical
problems.
 Specific conditions such as pre-eclampsia and massive
maternal haemorrhage significantly increase the risks of GA.
 GA in the obstetric population is often performed in a stressful
and pressured emergency situation.

40.  The physiological changes of pregnancy which contribute
to the challenges of general anaesthesia are considered
below:

41.  Respiratory, Increased risk of difficult intubation due to:
 • Airway oedema
 • Enlarged breasts and weight gain
 Rapid desaturation on induction due to:
 • displaced diaphragm and reduced FRC.
 • Increased closing capacity and small airway closure.

42.  • Increased oxygen consumption.
 Attention to effective preoxygenation
 action Regular failed intubation drill.
 Access and familiarity with
 difficult airway equipment

43.  Cardiovascular
 Decreased preload, decreased cardiac output
and placental perfusion due to Aorto-caval
compression by gravid uterus
 Action Maintain left lateral tilt of 15 during induction and until
baby delivered.
 Expanded plasma volume, physiologicalm anaemia,
decreased peripheral vascular resistance and increased
cardiac output
 action recognition that pregnant women may appear
relatively stable but may decompensate quickly

44.  Coagulation
 Hypercoaguable state.
 Consideration of thromboprophylaxis incl.
 compression stockings, early mobilisation, prophylactic
low molecular weight heparin

45.  Gastrointestinal
 Increased Intra-abdominal pressure and progesterone
mediated reduction in lower oesophageal sphincter tone
increase risk of reflux and acid aspiration
syndrome(Mendelson’s).

46.  Labour reduces gastric emptying, especially if
opioid analgesia used.
 action
 Prophylactic H2 antagonists.
 Sodium citrate immediately prior to induction.
 Rapid sequence induction with cricoid pressure

47.  General anesthesia principle
 Induction time to delivery is important as it dictates the
amount of volatile anaesthetic agent that transfers to the
neonate.
 Uterine incision to delivery is important as placental
blood flow may be disrupted by uterine incision and if
prolonged may increase the risk of fetal acidosis.

48.  Use of prokinetics (e.g. metoclopramide 10 mg I.V) •
 Use of H2 antagonists (e.g. Ranitidine 150mg p.o if time
permits or 50mg I.V prior to an emergency)
 Sodium citrate (30ml) p.o just prior to induction
 Cricoid Pressure
 10N
 30N
Rapid Sequence Induction

49. • Choice of Induction Agent
• Thiopentone 4 mg/kg
• Ketamine 1-1.5mg/kg
• Propofol
• etomidate
 Inhalational Induction
 risk of aspiration and the increased risk of uterine atony
and haemorrhage due to uterine muscle relaxation
caused by volatile agents.
Neuromuscular Blockade
Suxamethonium
Non-Depolarising (Rocuronium)

50.  Opioids
 Although not routinely used at induction because of
fears of neonatal respiratory depression, short
acting opioids have a place in general anaesthesia
for patients with hypertensive disorders, primarily
pre-eclampsia, to reduce the risk of cerebral
complications from the pressor response of
laryngoscopy.

51. Steps to follow when giving General anesthesia are include;
1.Administer a nonparticulate oral antacid (sodium citrate) before
induction of anesthesia with consideration for metoclopramide or a
histamine-2 blocker
2. Place standard monitors, maintain left uterine displacement, and ensure
suction, airway equipment, and appropriate drugs are readily available.
3. Ensure the patient has a working intravenous catheter and start an
infusion of crystalloid solution.preload ?
4. administer prophylactic antibiotics and participate in time-out checklist.

52.  5. Preoxygenate/denitrogenate patient for more than 3
minutes or 4 maximal (vital capacity) breaths over 30
seconds with 100% oxygen.
6. When the surgeon is ready and patient prepared, an
assistant should apply cricoid pressure (and maintain
until the position of the endotracheal tube is verifed).*
7. Notify and confrm with the surgeon that the patient is
ready for induction of anesthesia.

53.  8.Administer induction agent and muscle relaxant in rapid
sequence, wait 30 to 60 seconds, and then initiate direct
laryngoscopy for tracheal intubation. Consider using etomidate
or ketamine if concern for hypotension exists.
9. After confrming endotracheal tube placement, communicate
to surgeon to proceed with incision.
10. Administer 50% nitrous oxide in oxygen with 0.5 to 0.75
minimum alveolar concentration of a halogenated anesthetic.

54. 11. Adjust minute ventilation to maintain normocarbia (end-tidal
carbon dioxide 30 to 32 mm Hg).
12. After delivery, anesthesia may be augmented by adminis
tering opioids, barbiturates, or propofol while continuing the
volatile anesthetic. Additional muscle relaxant may be
considered if necessary.
13. Administer oxytocin and assess uterine tone.
14. Extubate the trachea when the patient is awake and follow
ing commands and neuromuscular blockade is fully reversed.

55.  Extubation
 The risks of extubation are often overlooked but it is
associated with airway difficulties, including upper
airway obstruction, laryngospasm and aspiration.
 The left lateral position is recommended

57. THE END