Aruna GodwinDepartment of Anesthesiology

Rashid Hospital Trauma CentreDubai Health Authority - UAE

Aruna GodwinDepartment of Anesthesiology

Rashid Hospital Trauma CentreDubai Health Authority - UAE

Spinal Hypotension in

Elective C section:How to prevent it.

Spinal Hypotension in

Elective C section:How to prevent it.

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 mgRopi = 12mg

Fat-soluble opioidsSufentanil 5 mcgFentanyl 10 mcg up to 25 mcg

Post op. analgesiaIntra thecal morphin 100 mcgTAP blocksContinuous wound infiltration **

* Gautier P BJA 2003** Rackelboom T Obst Gynecol Oct 2010** O’Neil Patricia ASA 2010

Effects of hypotension.

Dose of Spinal anesthetic.

Vasopressor of choice.

Intravenous fluid loading strategies.

Spinal Hypotension in Elective C section:

How to prevent it?

Maternal:*Nausea vomitingloss of consciounessaspiration

Foetal;**Decreased Uteroplacental perfusionUmbilical Ph lowFoetal acidosisAPGAR***

,

*Datta, S Alper,Anesthesiology** Ngan Kee,Anesthesiology.*** Sykes GS,Lancet

• Intrathecal opioids are synergistic with local anesthetics and intensify

sensory block without increasing sympathetic block.

Low dose spinal anesthesia

A randomized comparison of low doses of hyperbaric bupivacaine in combined spinal-epidural anesthesia for cesarean delivery*.

* Leo S Anesth Analg. 2009

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

Forest plot for hypotension comparing LD vs CD: individual trials and meta-analysis.

Arzola C , and Wieczorek P M Br. J. Anaesth. 2011

• 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*

Bupivacaine - sparing effect of fentanyl in spinal anesthesia for

cesarean delivery.

* Choi DH Reg Anesth Pain Med. 2000

• Low dose spinal anesthesia with Intrathecal opioids improved

maternal haemodynamics.

Low dose spinal anesthesia

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

* Lee A, Anesth Analg 2002;

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.

• Ephedrine vs Phenylephrine iv bolus • Phenylephrine 100mcg iv vs Ephedrine 5-10mg 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.

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

Spinal Timeincision

coloadingpreloading

Preloading or coloading ?

Crystalloid or Colloids (HES) ?

8 - 10 min

Dose study 10, 20 up to 30 mL/kg**:No difference in BP

No difference in CO

Preloading Vs no preloading*

* Rout et al. Anesthesiology 1993

** Park et al. Anesth Analg 1996

*** Mercier F in Editorial Anesth Analg oct2011

Crystalloid preloading no longer recommended***.

Meta analysis*

ˆdextrans and gelatine C.I. in obst

* Morgan PJ Anesth Analg 2001

Type of iv fluid

1.5L RL

0.5L HES

1.0LHES

Incidence of

hypotension

75% 58% 17%

Ueyama, Anesthesiology: 1999

• Meta analysis

• Emmet RS Cochrane library 2006

Meta analysis*

* 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

PreloadPreload ColoadCoload PP

Vol infused (mL)Vol infused (mL) 1474 1386 0.13

Duration of Infusion (min)Duration of Infusion (min) 20 9.8 0.01

SA inj to U incision (min)SA inj to U incision (min) 11.6 13.1 0.58

Eph pre delivery (mg) Eph pre delivery (mg) 10 [0-20] 0 [0-10] 0.03

# Pat w/o Ephedrine# Pat w/o Ephedrine 9/25 16/25 0.047

Incidence of HypotensionIncidence of Hypotension 60% 36%

Dyer et al. Anaesth Intensive Care 2004

• 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 130/0.4preloading (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•RCS : Colloid Preload to Coload During Spinal Anesthesia for Elective Cesarean Delivery

Siddik-Sayyid S Anesth Analg 2009Neonat. outcomes =

Colloid coloading =Colloid preloading

Teoh W et al. Anesth. Analg 2009

A & A

McDonald S, Anesth Analg October 2011

Requirements =

Coloading: Colloid vs crystalloid

SBP CO

HR SV

Colloid coload = Crystalloid coload…

McDonald S, Anesth Analg October 2011

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 90-100% baseline).

Spinal Hypotension in Elective C section:

How to prevent it?

Fluid loading + Vasopressor

Aruna GodwinDepartment of Anesthesiology

Rashid Hospital Trauma CentreDubai Health Authority - UAE

Aruna GodwinDepartment of Anesthesiology

Rashid Hospital Trauma CentreDubai Health Authority - UAE

Spinal Anesthesia : Don't do too much ! Bupi 8mg is sufficient with

opioids Post op analgesia...