The document discusses regional anesthesia techniques for caesarean section. It recommends using hyperbaric bupivacaine with fentanyl for spinal anesthesia. It suggests crystalloid cohydration for intravenous fluids and using phenylephrine instead of ephedrine as the vasopressor. The document also recommends combined spinal-epidural anesthesia to reduce spinal doses and improve hemodynamic stability. It provides guidance on epidural top-ups or converting to spinal anesthesia if the epidural fails. The key points emphasize optimal drug choices, fluid management, hemodynamic control and contingency plans for regional anesthesia during caesarean sections.

1. Regional Anaesthesia for
Caesarean Section
Warwick D. Ngan Kee
Dept of Anaesthesia & Intensive Care
The Chinese University of Hong Kong

2. OUTLINE:
• Spinal
 Drugs
 Fluids
 Blood Pressure
• CSE
 Dose
• Epidural
 Topup

3. OUTLINE:
• Spinal
 Drugs
 Fluids
 Blood Pressure
• CSE
 Dose
• Epidural
 Topup

4. Local
Anaesthetic
Bupivacaine
Bupivacaine is the local anaesthetic of choice

7. Hyperbaric vs Plain:
• Faster onset
• Less conversion to GA

9. Hyperbaric vs Plain:
• Faster onset
• Less conversion to GA
• Less variability of block
Hyperbaric local anaesthetic more reliable

10. Local
Anaesthetic
Bupivacaine
Additives +

11. • Opioids
• Adrenaline
• Clonidine
• Neostigmine
• Ketamine

12. Adding adjunct agents
Possible advantages:
1. Decrease side effects
2. Increase efficacy

13. Adding adjunct agents
Possible disadvantages:
1. Drug error
2. Breach of sterility
3. Incompatibility
4. Cost
5. Safety (often “off-label”)

14. • Opioids
• Adrenaline
• Clonidine
• Neostigmine
• Ketamine
Only add an opioid

15. Local
Anaesthetic
Lipophilic
+ Opioid
Bupivacaine Fentanyl

16. Bupivacaine Spinal
Added Fentanyl 0 - 50 μg

17. Intraoperative Opioid Supplementation
0 2.5 5 6.25 12.5 25 37 50
Fentanyl Dose (μg)
Intraop
Opioid
(%)
67%
50%
25%
0% 0% 0% 0% 0%
Hunt et al. Anesthesiology 1989;71:535-40.

18. Nausea and Vomiting?

20. Elective Spinal Caesarean (n=30)
Hyperbaric Bupivacaine 12 mg
• FENTANYL: Less intraoperative pain
• FENTANYL: Less intraoperative nausea
Manullang et al. Anesth Analg 2000;90:1162-6.
IV Ondansetron
4 mg
IT Fentanyl
15 μg
Adding an opioid improves patient comfort

21. Morphine
• 100 - 200 μg
• Preservative-free
• Postop analgesia
Morpheus

22. OUTLINE:
• Spinal
 Drugs
 Fluids
 Blood Pressure
• CSE
 Dose
• Epidural
 Topup

23. Intravenous fluids
Many Uncertainties

24. Colloid
vs
Crystalloid?

25. Prehydration
vs
Cohydration?

26. Prehydration
(Preload)
Rapid IV fluid
infusion started
before spinal injection

27. Cohydration
(Coload)
Rapid IV fluid
infusion started
after spinal injection

28. IV Fluid: Type and Timing
Crystalloid
Prehydration Cohydration
Colloid

29. IV Fluid: Type and Timing
Crystalloid
Prehydration Cohydration
Colloid
- +
+ +

30. Colloid Prehydration:
D I S A D V A N T A G E S
• Cost.
• Effects on coagulation.
• Fluid overload.
• Haemodilution.
• Allergic reactions.

31. Recommendation:
• Crystalloid: cohydration
• Colloid: prehydration or cohydration
• Don't rely on IV fluids
• Don't delay for IV fluids

32. OUTLINE:
• Spinal
 Drugs
 Fluids
 Blood Pressure
• CSE
 Dose
• Epidural
 Topup

33. AA LL PP HH AA AA GG OO NN II SS TT SS
Phenylephrine

34. AA LL PP HH AA AA GG OO NN II SS TT SS
Why use phenylephrine?
• Phenylephrine is more effective
Phenylephrine

35. Ephedrine Phenylephrine
carbon
hydrogen
oxygen
nitrogen

36. AA LL PP HH AA AA GG OO NN II SS TT SS
Why use phenylephrine?
• Phenylephrine is more effective
• Ephedrine causes fetal acidosis
Phenylephrine

37. Ephedrine depresses fetal pH and BE
Figure 1. Meta-analysis of trials - effect on umbilical arterial pH
Favours ephedrine Favours phenylephrine
Alahuhta
Hall
LaPorta
Moran
Pierce
Thomas
Overall effect
-0.10 -0.05 0.00 0.05 0.10
Weighted mean difference (umbilical cord arterial blood pH)
Lee A, Ngan Kee WD, Gin T. Anesth Analg 2002;94 920-6.

39. Umbilical Venous : Maternal Arterial
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
1.13
(Median values)
* P < 0.0001
0.17 *
Ephedrine Phenylephrine
Ngan Kee WD Anesthesiology 2009; 111:506-12
Ephedrine crosses the placenta more

40. How to use phenylephrine?
Phenylephrine
• Preparation
• Timing
• Method of Giving

41. Preparation....
Dilute carefully…..
+ = 100 μg/ml
10 mg / 1ml 100 ml

42. Timing....
Prevention versus Treatment
Most effective management:
•Start administration immediately after
intrathecal injection

43. Method of Giving....
Infusion versus Boluses
• Both effective
• Intermittent bolus simple
• Infusion convenient

44. Recommendation:
Bolus technique:
• Bolus dose: 50-100 μg (0.5-1ml)
• Begin immediately after IT injection
• Measure BP Q1min
• Further boluses when BP start to decrease

45. Recommendation:
Infusion technique:
• Syringe pump
• Start ~50 μg/min immediately after induction
• Measure BP Q1min
• Increase rate if BP falls
• Decrease/stop if BP increases

46. Recommendation:
What about bradycardia?
• Associated with ¯cardiac output
• Tolerate to ~ 50-60 bpm
• BP high/normal: stop and wait!
• BP low: IVF, ephedrine,
atropine/glycopyrrolate*
* Beware hypertension with
anticholinergics!

47. Recommendation:
What about high risk cases?
• Preeclampsia
• Fetal compromise
• Few studies
• Less vasopressor needed
• Use less aggressive dosing

48. OUTLINE:
• Spinal
 Drugs
 Fluids
 Blood Pressure
• CSE
 Dose
• Epidural
 Topup

49. Single shot spinal
Dose required for adequate spinal block

50. Single shot spinal
Dose required for adequate spinal block

51. CSE
Dose required for adequate spinal block

53. Incidence of Hypotension
100
80
60
40
20
0
**
P < 0.001
Low Dose Standard
Hypotension
(%) 73%
14%
Teoh et al. Int J Obstet Anesth 2006;15:273-8

54. OUTLINE:
• Spinal
 Drugs
 Fluids
 Blood Pressure
• CSE
 Dose
• Epidural
 Topup

55. 2008-2009
• 93,000 Emerg C-sections
• 22% Epidural Anaesthesia
Labour Epidural Topups
Hillyard et al. Br J Anaesth 2011;107:668-78

56. Type of Anaesthetic?
Assessment of Urgency
GA Regional
Assessment of Epidural Function
OK
Epidural Topup
Not OK
De Novo Spinal
(or CSE)
(With informed consent)

57. Assessment of Epidural Function

58. Epidural Topup….
….or De Novo Spinal?
Assessing Epidural:
• How is pain control?
• What is block height?
• How much local anaesthetic?
• How frequent interventions?

59. Epidural Topup….
….What Drug?

60. Bupivacaine
Levobupivacaine
Ropivacaine
Lidocaine
(+ epinephrine)

61. Emergency
TOPUPS
CONSIDERATIONS
• Often given under time pressure
• Large dose, given rapidly
• Speed of onset
• Safety

62. • If the quality of epidural block is paramount, then
0.75% ropivacaine is suggested.
• If the speed of onset is important, then a lidocaine
and epinephrine solution, with or without fentanyl,
appears optimal

63. Complications of Extension of
Complications of Extension of
Epidural Block
Epidural Block
8
14
6
2
1
12
Regan KL, O'Sullivan G. Anaesthesia 2008;63:136-42

64. F A I L E D B L O C K

65. F A I L E D B L O C K
Assessment & Discussion
GA Regional
De Novo Spinal
(or CSE)
(With informed consent)

67. 0.16%
11.1%
Furst SR, Reisner LS. J Clin Anesthesia 1995;7:71-4
Spinal After Epidural: Risk of High Block

68. F A I L E D B L O C K
Assessment & Discussion
GA Regional
De Novo Spinal
(or CSE)
Reduce Dose

69. Regional Anaesthesia for
Caesarean Section
K E Y P O I N T S

70. Regional Anaesthesia for
Caesarean Section
K E Y P O I N T S
Spinal Anaesthesia
• Hyperbaric local anaesthetic
• + Fentanyl / Sufentanil
• ± Morphine

71. Regional Anaesthesia for
Caesarean Section
K E Y P O I N T S
Intravenous Fluids
• Crystalloid cohydration
• Colloid prehydration or cohydration
• No need to delay for fluids

72. Regional Anaesthesia for
Caesarean Section
K E Y P O I N T S
Vasopressors
• Avoid large doses of ephedrine before delivery
• Phenylephrine preferred
• Bolus or infusion
• Bradycardia: stop and wait.

73. Regional Anaesthesia for
Caesarean Section
K E Y P O I N T S
Combined Spinal Epidural (CSE)
• Good for reducing dose
• Better haemodynamic stability
• Useful for prolonged surgery

74. Regional Anaesthesia for
Caesarean Section
K E Y P O I N T S
Epidural Topup for C-Section
• 2% Lidocaine + Adrenaline ± Bicarbonate
• 0.75% Ropivacaine
• Spinal after epidural: reduce dose

75. Regional Anaesthesia for
Caesarean Section
Warwick D. Ngan Kee
Dept of Anaesthesia & Intensive Care
The Chinese University of Hong Kong