Spinal Hypotension in
Elective C section:
How to prevent it.
Aruna Godwin
Department of Anesthesiology
Rashid Hospital Trauma Centre
Dubai Health Authority - UAE
USA = up to 39 %
x 10 in 70 years
Europe = up to 20..25%
UAE = up to 29 %
Brazil up to 80% in private
Spinal anesthesia is a Gold standard
Incidence of hypotension up to 52-80%
Local anesthesic:*
Levo-bupi = Bupi = 8 mg
Ropi = 12mg
 Fat-soluble opioids
Sufentanil 5 mcg
Fentanyl 10 mcg up to 25 mcg
Post op. analgesia
Intra thecal morphin 100 mcg
TAP blocks
Continuous wound infiltration **
* Gautier P BJA 2003
** Rackelboom T Obst Gynecol Oct 2010
** O’Neil Patricia ASA 2010
Spinal Hypotension in Elective C section:
How to prevent it?
Effects of hypotension.
Dose of Spinal anesthetic.
Vasopressor of choice.
Intravenous fluid loading
strategies.
Maternal:*
Nausea vomiting
loss of consciouness
aspiration
Foetal;**
Decreased Uteroplacental perfusion
Umbilical Ph low
Foetal acidosis
APGAR***
,
*Datta, S Alper,Anesthesiology
** Ngan Kee,Anesthesiology.
*** Sykes GS,Lancet
Low dose spinal anesthesia
•
Intrathecal opioids are synergistic
with local anesthetics and intensify
sensory block without increasing
sympathetic block.
A randomized comparison of low doses of hyperbaric
bupivacaine in combined spinal-epidural anesthesia for
cesarean delivery*.
Incidence of
Hypotension
Gp 7mg
Gp 8mg
Gp 9mg
P = 0.04
30%
55%
70%
Time taken to reach T4 was similar.
No patient had inadequate anesthesia
* Leo S Anesth Analg. 2009
Forest plot for hypotension comparing LD vs CD: individual trials and meta-analysis.
Arzola C , and Wieczorek P M Br. J. Anaesth. 2011
Bupivacaine - sparing effect of fentanyl in
spinal anesthesia for cesarean delivery.
•
CONCLUSIONS:
•
The optimal dose of hyperbaric bupivacaine to produce surgical
anesthesia was 12 mg, which was accompanied by high sensory
block. With the addition of 10 microg of fentanyl, the dose of
bupivacaine could be reduced to 8 mg in spinal anesthesia for
cesarean delivery*
* Choi DH Reg Anesth Pain Med. 2000
Low dose spinal anesthesia
•
Low dose spinal anesthesia with
Intrathecal opioids improved
maternal haemodynamics.
Non pharmacological methods
15° left lateral tilt... => Still 70- 80%*
Pharmacological methods
Vasopressors (Phenylephrine or ephedrine)
IV fluid loading
Ephedrine or Phenylephrine ???
Prophylactic infusion, on demand
or combined with fluid loading.
•
Ephedrine:
Recent evidence* suggests that ephedrine causes
neonatal acidosis, and large doses may be harmful in a
compromised fetus, by increasing oxygen demand and
anaerobic metabolism.
Placental transfer and fetal metabolic effects of
phenylephrine and ephedrine during spinal anesthesia
for cesarean delivery**.
* Riley ET. Int Anesthesiol Clin 2007.
** Ngan Kee WD, Karmakar MK Anesthesiology 2009.
Phenylephrine.
 Has direct effect on alpha-1 receptor..
Potent
short-acting vasoconstrictor.
Better neonatal outcome and higher umbilical artery pH
values .


Incidence of maternal bradycardia was as high 27% without
coloading, 17% with coloading with crystalloids.
*CooperDW,Anesthesiology2002
*
A quantitative systematic review of randomized controlled trials of ephedrine
compared with phenylephrine for the manage- ment of hypotension during
spinal anesthesia for cesarean delivery*.
This shows the effect of
choice of vasopressor on
umbilical cord arterial pH.
Data are mean difference with
95% confidence intervals.
* Lee A, Anesth Analg 2002;
•
Ephedrine vs Phenylephrine iv bolus
•
Phenylephrine 100mcg iv
•
( Phenylephrine had a faster onset of action, low incidence
of IONV).*
•
Lower dose of phenylephrine (40-80mcg iv ) failed to reduce
the incidence of IONV and hypotension.**
•
Combination of low dose phenylephrine 20mcg and
ephedrine 5mg – not effective.***
* Ngan Kee,Anesthesia 2008,
•
** Dyer,Anesthesiology2009,
•
***Datta,Anesth2005.
vs Ephedrine 5-10mg iv
Prophylactic Phenylephrine infusions vs bolus:
Phenylephrine inf 25-50mcgm/min* better than
phenylephrine iv bolus.
•
Phenylephrine
25-50mcg/min
inf
100mcg bolus
Incidence of
hypotension
13-23%
85-88%
* Allen TK Analg2010 ,
•
•
Prophylactic Phenylephrine infusions :
High dose 100 mcgm/min is associated with hypertensive
episodes and maternal bradycardia. **
•
Titration recommmended.
•
* * Ngan Kee,Anesth Analg2008.
•The
Proposal :
•Low
dose prophylactic
phenylephrine infusions in
combination with iv fluid loading.
Ngan Kee,Curr opin Anesthesiol,2010
Preloading or coloading ?
Crystalloid or Colloids (HES) ?
8 - 10 min
preloading
coloading
Spinal
incision
Time
Preloading Vs no preloading*
Dose study 10, 20 up to 30 mL/kg**:
No difference in BP
No difference in CO
Crystalloid preloading no longer recommended***.
* Rout et al. Anesthesiology 1993
** Park et al. Anesth Analg 1996
*** Mercier F in Editorial Anesth Analg oct2011
Meta analysis*
* Morgan PJ Anesth Analg 2001
ˆdextrans and gelatine C.I. in obst
Type of iv
fluid
1.5L
RL
0.5L
HES
1.0L
HES
Incidence of
hypotension
75%
58%
17%
Ueyama, Anesthesiology: 1999
Meta analysis*
•
Meta analysis
•
Emmet RS Cochrane library 2006
* Emmet RS Cochrane library 2006
Colloid preloading 10- 15ml/kg
more effective than crystalloid
preloading in preventing spinal
induced hypotension.
Riley ET, Anesth Analg 1995
Crystalloid preload vs rapid coload
Preload
Coload
P
1474
1386
0.13
Duration of Infusion (min) 20
9.8
0.01
SA inj to U incision (min)
11.6
13.1
0.58
Eph pre delivery (mg)
10 [0-20] 0 [0-10]
0.03
# Pat w/o Ephedrine
9/25
0.047
Vol infused (mL)
Incidence of Hypotension 60%
Dyer et al. Anaesth Intensive Care 2004
16/25
36%
•
No preload + Phenylephrine (0) vs rapid coload (1)
Ngan kee WD et al. Anesthesiology 2005
Crystalloid coloading 20ml/kg
more effective than crystalloid
preloading in preventing spinal
induced hypotension.
Dyer et al. Anaesth Intensive Care 2004
Colloid HES 130/0.4
preloading (P) vs coloading (C) (15ml/kg)
P>
No difference in maternal
and neonatal outcomes
* Teoh W et al. Anesth. Analg 2009
•RCS
: Colloid Preload to Coload During Spinal Anesthesia
for Elective Cesarean Delivery
Siddik-Sayyid S Anesth Analg 2009
Neonat. outcomes =
Colloid coloading
=
Colloid preloading
Teoh W et al. Anesth. Analg 2009
A&A
Coloading: Colloid vs crystalloid
SBP
CO
HR
SV
McDonald S, Anesth Analg October 2011
Requirements =
Colloid coload
=
Crystalloid coload…
McDonald S, Anesth Analg October 2011
Spinal Hypotension in Elective C section:
How to prevent it?
Crystalloid preloading : NO
Crystalloid rapid coloading : Yes 20ml/kg / 8 min.
• Colloids (HES) preloading :YES 10- 15 mL/kg
• Colloids coloading = Colloid Preloading
• Colloid coloading = crystalloid coloading.
• Vasopressor = Phenylephrine to maintain SBP 90100% baseline).
Fluid loading + Vasopressor
Spinal Anesthesia : Don't do too much !
Bupi 8mg is sufficient with opioids
Post op analgesia...
Aruna Godwin
Department of Anesthesiology
Rashid Hospital Trauma Centre
Dubai Health Authority - UAE