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.
38.
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
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
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)
58. Epidural Topup….
….or De Novo Spinal?
Assessing Epidural:
• How is pain control?
• What is block height?
• How much local anaesthetic?
• How frequent interventions?
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
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
