General anesthesia General anesthesia for for cesarean cesarean section : section : whatwhat’’s s new ?new ?

Laurent ThierrinLaurent ThierrinService dService d’’anesthanesthéésiologiesiologieCHUV, CHCHUV, CH--1011 Lausanne1011 LausanneMarch 1March 1stst 20082008

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History

General anesthesiaGeneral anesthesia forfor cesareancesareansection :section : whatwhat’’ss new ?new ?

GA for cesarean sectionGA for cesarean section

HistoryHistory�� 1847 :1847 : first obstetrical anesthesia with ether by first obstetrical anesthesia with ether by SimpsonSimpson

�� 1853 :1853 : Queen Victoria GA with chloroform by Queen Victoria GA with chloroform by SnowSnow

�� Beginning of 20th century :Beginning of 20th century : first GAs for CS with etherfirst GAs for CS with ether

�� 1935 :1935 : thiopentone is discoveredthiopentone is discovered

�� 1946 : 1946 : gastric aspiration is described by gastric aspiration is described by MendelsonMendelson

�� 1951 :1951 : suxamethonium (succinylcholine) is discoveredsuxamethonium (succinylcholine) is discovered

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Thiopentone and suxamethoniumThiopentone and suxamethoniumintravenous induction in semiintravenous induction in semi--sitting positionsitting position

IntubationIntubation

GA maintenance with nitrous oxide and oxygenGA maintenance with nitrous oxide and oxygen

No preoxygenationNo preoxygenationMask ventilation before intubationMask ventilation before intubation

No cricoid pressureNo cricoid pressureNo halogenated anestheticsNo halogenated anesthetics

but but ……

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ADVANTAGESSpeed of anesthesia

Muscle relaxation

DISADVANTAGESMendelson’s syndrome

Failed intubation

Scott DB. Awareness during caesareansection. Anaesthesia 1991;46:693-4.

From “Why Mothers Die 2000-2002”

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PreoxygenationPreoxygenation

IntubationIntubation

GA maintenance with OGA maintenance with O22/N/N22O (50:50)O (50:50)and 0,5% halothane (+ tubocurarine)and 0,5% halothane (+ tubocurarine)

Thiopentone and suxamethoniumThiopentone and suxamethoniumintravenous crush inductionintravenous crush induction

GA for cesarean section : epidemiologyGA for cesarean section : epidemiology

Maternal deaths from anesthesiaMaternal deaths from anesthesia

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Cooper GM, McClure JH. Maternal deaths from anaesthesia. An extract from Why Mothers Die 2000-2002, the Confidential Enquiries into Maternal Deaths in the United Kingdom: Chapter 9: Anaesthesia. Br J Anaesth 2005;94:417-23.

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Epidemiology

General anesthesiaGeneral anesthesia forfor cesareancesareansection :section : whatwhat’’ss new ?new ?

GA for cesarean section GA for cesarean section

EpidemiologyEpidemiology

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CS proportionCS proportionCS proportionCS proportion

CS with GA proportionCS with GA proportionCS with GA proportionCS with GA proportion

Rahman K, Jenkins JG. Failed tracheal intubation in obstetrics: no more frequent but still managed badly. Anaesthesia 2005;60:168-71.

More indications :• podalic presentation• multiple pregnancy• maternal wish

Demographic factors :• ↑ maternal age• ↑ maternal obesity• ↑ multiple pregnancy

More frequent use of neuraxial techniques

GA for cesarean section : epidemiology GA for cesarean section : epidemiology

AnesthetistAnesthetist’’s trainings training

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Number of GA for CS

Number of anesthetists

GA for cesarean section : epidemiologyGA for cesarean section : epidemiology

Do we have to react and how ?Do we have to react and how ?

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Anesthetic technique

General anesthesiaGeneral anesthesia forfor cesareancesareansection :section : whatwhat’’ss new ?new ?

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Anesthetic technique

General anesthesiaGeneral anesthesia forfor cesareancesareansection :section : whatwhat’’ss new ?new ?

Rapide sequence induction ?

GA for cesarean section : induction sequenceGA for cesarean section : induction sequence

Why a rapide sequence induction ?Why a rapide sequence induction ?�� Significant decrease in pulmonary aspirationSignificant decrease in pulmonary aspiration

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Only 4 maternal deaths from pulmonary aspiration over 10 Only 4 maternal deaths from pulmonary aspiration over 10 millions births in UK during 15 years !millions births in UK during 15 years !

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Traditional rapid sequence induction is anoutmoded technique for Caesarean section

and should be modified. Int J Obstet Anesth 2006;15:227-32.

Proposer : Levy DM Opposer : Meek T

�� Thiopentone is not the first choiceThiopentone is not the first choice

�� Suxamethonium is not the first Suxamethonium is not the first choicechoice

�� Cricoid pressure is useless and Cricoid pressure is useless and dangerousdangerous

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GA for cesarean section : induction sequence GA for cesarean section : induction sequence

Why is traditional rapid sequence Why is traditional rapid sequence induction outmoded ?induction outmoded ?

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Anesthetic technique

General anesthesiaGeneral anesthesia forfor cesareancesareansection :section : whatwhat’’ss new ?new ?

Which agent for induction ?

GA for cesarean section : which agent for induction ?GA for cesarean section : which agent for induction ?

Why propofol instead of thiopentone ?Why propofol instead of thiopentone ?

�� More frequently usedMore frequently used

�� Less expensiveLess expensive

�� Faster recoveryFaster recovery

�� Better recoveryBetter recovery

�� Less PONVLess PONV19

�� Pain with injectionPain with injection

�� More hypotensionMore hypotension

�� More bradycardiaMore bradycardia

�� More awarenessMore awareness

�� More neonatal depressionMore neonatal depression20

GA for cesarean section : which agent for induction ?GA for cesarean section : which agent for induction ?

Why not propofol?Why not propofol?

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Propofol should be the agent of choice for caesarean section under general anaesthesia.

Int J Obstet Anesth 2003;12:275-9.

Proposer : Duggal K Opposer : Russell R

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Anesthetic technique

General anesthesiaGeneral anesthesia forfor cesareancesareansection :section : whatwhat’’ss new ?new ?

Which myorelaxant for induction ?

�� Anaphylactic reactionAnaphylactic reaction

�� Malignant hyperthermiaMalignant hyperthermia

�� Prolonged effect with pregnancyProlonged effect with pregnancy

�� Hyperkaliemia Hyperkaliemia

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GA for cesarean section : which myorelaxant for induction ? GA for cesarean section : which myorelaxant for induction ?

Why not succinylcholine ?Why not succinylcholine ?

GA for cesarean section : which myorelaxant for induction ? GA for cesarean section : which myorelaxant for induction ?

Why succinylcholine instead of Why succinylcholine instead of rocuronium ?rocuronium ?

�� Better intubation conditionsBetter intubation conditions

�� Faster effectFaster effect

�� Shorter duration of effectShorter duration of effect

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GA for cesarean section : which myorelaxant for induction ? GA for cesarean section : which myorelaxant for induction ?

Succinylcholine vs RocuroniumSuccinylcholine vs Rocuronium

Perry JJ, Lee J, Wells G. Are intubation conditions using rocuroniumequivalent to those using succinylcholine? Acad Emerg Med 2002;9:813-23.

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GA for cesarean section : which myorelaxant for induction ? GA for cesarean section : which myorelaxant for induction ?

Succinylcholine vs RocuroniumSuccinylcholine vs Rocuronium

Sluga M, Ummenhofer W, Studer W et al. Rocuronium versus succinylcholine for rapid sequence induction of anesthesia and endotracheal intubation: a prospective, randomized trial in emergent cases. Anesth Analg 2005;101:1356-61.

180 ISRIPropofol +

Succinylcholine Rocuronium

N=90 N=90

Laryngoscopy after fasciculations

Laryngoscopy 60 sec after

injection

Intubation

Rocuronium0.6 mg/kg0.6 mg/kg0.6 mg/kg0.6 mg/kg

Succinylcholine1 mg/kg

Time to have an endotrachealtube in place

+Intubations conditions

T0

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GA for cesarean section : which myorelaxant for induction ?GA for cesarean section : which myorelaxant for induction ?

Succinylcholine vs RocuroniumSuccinylcholine vs RocuroniumOne molecule will probably change our vision :

C72H104Na8O48S8

SuggamadexORG 25969

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Anesthetic technique

General anesthesiaGeneral anesthesia forfor cesareancesareansection :section : whatwhat’’ss new ?new ?

Opioids at induction ?

GA for cesarean section : opioids at induction ?GA for cesarean section : opioids at induction ?

Remifentanil 0,5 Remifentanil 0,5 µµg/kg + 0,2 g/kg + 0,2 µµg/kg/ming/kg/min

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Van de Velde M, Teunkens A, Kuypers M et al. General anaesthesia with targetcontrolled infusion of propofol for planned caesarean section: maternal and neonataleffects of a remifentanil-based technique. Int J Obstet Anesth 2004;13:153-8.

GA for cesarean section : opioids at induction ?GA for cesarean section : opioids at induction ?

Remifentanil 1 Remifentanil 1 µµg/kg ivg/kg iv

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Kee WD, Khaw KS, Ma KC et al. Maternal and neonatal effects of remifentanil at induction of general anesthesia for cesarean delivery: a randomized, double-blind, controlled trial. Anesthesiology 2006;104:14-20.

UV/MA = 0,73

UA/UV = 0,602/20 neonates → naloxone

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Anesthetic technique

General anesthesiaGeneral anesthesia forfor cesareancesareansection :section : whatwhat’’ss new ?new ?

Cricoid pressure ?

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GA for cesarean section : cricoid pressure ? GA for cesarean section : cricoid pressure ?

SellickSellick’’s manoeuvre legitimacys manoeuvre legitimacy

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Specific risks

General anesthesiaGeneral anesthesia forfor cesareancesareansection :section : whatwhat’’ss new ?new ?

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Specific risks

General anesthesiaGeneral anesthesia forfor cesareancesareansection :section : whatwhat’’ss new ?new ?

Difficult intubation

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GA for cesarean section : specific risks GA for cesarean section : specific risks

Difficult intubation in obstetricsDifficult intubation in obstetricsGoldszmidt E. Is there a difference between the obstetric and non-obstetric airway ? In: Halpern SH, Douglas MJ, eds. Evidence-based obstetric anesthesia: Blackwell BMJ Books, 2005:225-36.

Intubation difficulty : 1-6%Intubation failure : 0,1-0,6%

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GA for cesarean section : specific risks GA for cesarean section : specific risks

Difficult intubation in obstetricsDifficult intubation in obstetricsGoldszmidt E. Is there a difference between the obstetric and non-obstetric airway ? In: Halpern SH, Douglas MJ, eds. Evidence-based obstetric anesthesia: Blackwell BMJ Books, 2005:225-36.

No evidence of any difference at presentNo evidence of any difference at present

but but …… this could change soon because :this could change soon because :

Obesity prevalence Obesity prevalence ↑↑Maternal age Maternal age ↑↑

Preeclampsia Preeclampsia ↑↑

Recognized factors for a difficult intubationRecognized factors for a difficult intubation

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Specific risks

General anesthesiaGeneral anesthesia forfor cesareancesareansection :section : whatwhat’’ss new ?new ?

Awareness

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GA for cesarean section : specific risksGA for cesarean section : specific risks

Influence of the anesthetic regimen Influence of the anesthetic regimen on awarenesson awareness

Lyons G, Macdonald R. Awareness during caesarean section. Anaesthesia 1991;46:62-4.

Thiopentone 3-4 mg/kgHalothane 0,5%

Thiopentone 5-7 mg/kgIsoflurane 1%

1,3%1,3%1,3%1,3%

0,4%0,4%0,4%0,4%

7,4%7,4%7,4%7,4%

4,7%4,7%4,7%4,7%

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GA for cesarean section : specific risksGA for cesarean section : specific risks

BB--Aware studyAware study

Myles PS, Leslie K, McNeil J et al. Bispectral index monitoring to prevent awarenessduring anaesthesia: the B-Aware randomised controlled trial. Lancet 2004;363:1757-63.

2463 patients at risk of awareness :Cardiac surgeryGA for CSPolytrauma

1238standard monitoring

1225standard monitoring + BIS

awareness 110,89%

awareness 20,16%

↓ awareness risk : 82%NNT 138 x 16$ = 2’200$

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GA for cesarean section : awareness risk GA for cesarean section : awareness risk

Sevoflurane 1% vs 1,5%Sevoflurane 1% vs 1,5%

Chin KJ, Yeo SW. Bispectral index values at sevoflurane concentrations of 1% and 1.5% inlower segment cesarean delivery. Anesth Analg 2004;98:1140-4, table of contents.

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GA for cesarean section : awareness risk GA for cesarean section : awareness risk

Sevoflurane ECSevoflurane EC5050

Chin KJ, Yeo SW. A BIS-guided study of sevoflurane requirements for adequate depth of anaesthesia in Caesarean section. Anaesthesia 2004;59:1064-8.

ECECECEC95959595 = 1,41%= 1,41%= 1,41%= 1,41%

GA for cesarean section : whatGA for cesarean section : what’’s new ? s new ?

Take home messages ITake home messages I�� General anesthesia is needed for 5General anesthesia is needed for 5--10% of cesarean 10% of cesarean

sections, most frequently in emergency situations.sections, most frequently in emergency situations.

�� Decreasing rate of general anesthesia is associated with Decreasing rate of general anesthesia is associated with decreasing anesthetistsdecreasing anesthetists’’s training. Simulations training. Simulation--based training based training is becoming mandatory.is becoming mandatory.

�� Except a significant increase in anesthetic agents dosage, Except a significant increase in anesthetic agents dosage, recommended anesthetic technique is identical to the one recommended anesthetic technique is identical to the one described 40 years ago by Donald D. Moir.described 40 years ago by Donald D. Moir.

�� Thiopentone (5Thiopentone (5--7 mg/kg) is the first choice for induction. 7 mg/kg) is the first choice for induction. Propofol (2,5Propofol (2,5--3 mg/kg) is an acceptable second choice.3 mg/kg) is an acceptable second choice.

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GA for cesarean section : whatGA for cesarean section : what’’s new ? s new ?

Take home messages IITake home messages II�� Succinylcholine (1Succinylcholine (1--1,5 mg/kg) is the first choice as 1,5 mg/kg) is the first choice as

myorelaxant. Rocuronium (1 mg/kg) is an acceptable myorelaxant. Rocuronium (1 mg/kg) is an acceptable second choice. Suggamadex will possibly change this second choice. Suggamadex will possibly change this recommendation in the future.recommendation in the future.

�� Cricoid pressure (SellickCricoid pressure (Sellick’’s manoeuvre) :s manoeuvre) :�� Is frequently bad applied.Is frequently bad applied.�� May interfere with airway management.May interfere with airway management.�� Has not proved to reduce the incidence of aspiration during a raHas not proved to reduce the incidence of aspiration during a rapid pid

sequence intubation.sequence intubation.

�� 0,75 MAC volatile anesthetic agent (sevoflurane, isoflurane, 0,75 MAC volatile anesthetic agent (sevoflurane, isoflurane, desflurane) in an oxygen/nitrous oxide mixture is the first desflurane) in an oxygen/nitrous oxide mixture is the first choice for anesthesia maintenance until birth.choice for anesthesia maintenance until birth.

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GA for cesarean section : whatGA for cesarean section : what’’s new ? s new ?

Take home messages IIITake home messages III�� Opioids should not be used routinely in general anesthesia Opioids should not be used routinely in general anesthesia

for cesarean delivery because of neonatal respiratory for cesarean delivery because of neonatal respiratory depression.depression.

�� Remifentanil is a useful adjunct for improving maternal Remifentanil is a useful adjunct for improving maternal hemodynamics stability during GA for CS when there is clear hemodynamics stability during GA for CS when there is clear maternal indication (severe preeclampsia notably) and maternal indication (severe preeclampsia notably) and adequate facilities for neonatal resuscitation.adequate facilities for neonatal resuscitation.

�� The BIS monitor may help in determining the concentration of The BIS monitor may help in determining the concentration of volatile anesthetic necessary for adequate depth of volatile anesthetic necessary for adequate depth of anesthesia between induction and birth and thus decrease anesthesia between induction and birth and thus decrease the risk of awareness.the risk of awareness.

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THANK YOU for your attention !