Anest gen nel cesareo

1)Mortalità materna
2)Anest generale nel
cesareo urgente e non
Claudio Melloni
Direttore U.O.Anestesia e Rianimazione
Ospedale di Faenza

Servizio di Anestesia e Rianimazione Ospedale di Faenza(RA)

Allan C. Barnes, M.D., Professor of Obstetrics and
Gynecology, Johns Hopkins University, circa 1965.
The removal of a brain tumor in an elderly patient calls for a
surgeon with two assistants, scrub nurse and two circulating
nurses, and an anesthetist and an assistant. The patient's
prognosis is about 18 months and the hospital investment is
tremendous. In contrast, the birth of a new baby at 4:00 a.m.
is more often attended by one physician, no scrub nurse, one
circulating nurse and inadequate or haphazard anesthesia
coverage. As a profession, we seem to be committed to the
fallacy that to be interesting, one has to be an adult, fully
developed, and preferably degenerating.

Ostetricia ad alto rischio:posto per la regionale…..

Una buona scelta anestetica puo’
migliorare la situazione:
» epid * PIH/preeclampsia

Una cattiva scelta anestetica puo’
peggiorare la situazione:
» GA & intubaz. Difficile:l’autostrada per il
disastro….

WHO
Mortalità materna:
5-10/100.000 gravidanze paesi
sviluppati
500-1000 /100.000 paesi sottosviluppati

500.000 morti materne per
anno

Betran et al National estimates for maternal mortality:an
analysis based on WHO Systematic Review of maternal
mortality ane morbidity .BMC Public Health 2005,5.131


Dati WHO 1990


Mortalità materna in Italia


Mortalità materna in England e Wales
1847-1984


«Underreporting »
Francia 56%
– Bouvier-Colle.J.Int.J.Epidemiol 1991

Olanda 26%
– Schuitemaker Obstet.Gynecol 1997

Austria 38%
– Karimian Acta Obstet Gynecol Scand 2002

Finlandia 60%
– Gissler Acta Obstet Gynecol Scand 1997


Ministero della Salute

La mortalità materna è
stata inclusa negli eventi
sentinella per lo studio e la
riduzione del rischio clinico


CP.Anesthesia related deaths during obstetric
delivery in the United States(Anesthesiology
1997;86:277-84).

Morti materne in USA 1979-1990
cause
Relazione con l’anestesia
Tipo di procedura ostetrica
Condizioni materne concomitanti


Hawkins et al.Anesthesia related deaths during
obstetric delivery in the United States(Anesthesiology
1997;86:277-84).
num.tot=129
18
16
14
12
10
%
8
6
4
2
0

GA
REG
ignota
sedazione

79-81

82-84

85-87

88-90


CP.Anesthesia related deaths during obstetric
delivery in the United States(Anesthesiology
1997;86:277-84).

M o r t a lit à o s t e t r ic a
C S 82%

p a rto v a g 5 %

ig n o to 1 3 %


C/S Mortality (from Hawkins…)

AG:
52% d el total e
asp i r az
33%

p rob l d i i n d u z/ i n t u b az
22%

ven t i l a z i n ad eg
15%

O ppioidi o sedativi paren t
3%

i n su f resp
3%

arrest o card d u ran t e an est
22%

R egionale
25 %
ep i d u r a l e
70%


sp i n al e
30%

Number of deaths during cesarean section
Number of deaths during cesarean section

USA 1979-1990(Hawkins et al.Anesthesiology 86;280:1997)

1979-1984

1985-1990

GA

33

32

REG

19

9


Fatality rates during cesarean
Fatality rates during cesarean
section
section
per million of Ga or REG

1979-1984

1985-1990

G.A.

20

32.3

REG

8.6

1.9


Causes of anesthesia related deaths
Causes of anesthesia related deaths

USA 1979-1990(Hawkins et al.Anesthesiology 86;280:1997)

AG(67) Reg(33) sedaz(4) ignota(25) %

N

Probl.vie aeree

73

-

75

40

49

62

arresto card.intraop

22

6

-

52

23

30

tox da AL

51 -

-

13

17

spi/pd alta

36

-

-

9

12

iperdosaggio

-

25

-

1

1

anafilassi

-

-

4

1

1

5

6

-

4

5

6

100

100

100

100

129

ignota
%

100


Incidenza della mortalità materna da
CDC USA: GA vs reg.

GA 2.3 * > reg (1979—1984)
GA 16.7 * > reg ( 1985—1990).


Mortalità materna attribuita all’anestesia

4.3/milione di nati
vivi( 1979—1981)

8.7/milione di nati
vivi( 1979—1981)

1.7/ milione di nati
vivi (1988—1990).
CDC USA

1.7/ milione di nati
vivi (1988—1990).

CEMDEW


Report on Confidential enquiries into maternal deaths in
England and Wales 1970-1999
Frequenza per milione di gravid.stimate
35

emb.polm

30

ipertens

25

anest

20

emb.fluido amniotico

15

aborto
gravid.ectopica

10

emorragia

5
0

sepsi

19 73- 76- 79- 82- 8570- 75 78 81 84 87
72

88- 9190 93

94- 9796 99

rottura utero
altre cause dirette

Entrata Faenza(RA)
Servizio di Anestesia e Rianimazione Ospedale di in vigore della nuova classificazione

Mortalità ostetrica attribuita all’anestesia
1970-1999 CEMDUK
14
12
10
8
6
4
2
0

19
7072

7375

7678

7981

8284

8587

8890

9193

9496

9799


Effetti ipotensivi
dell’ossitocina


Fatti salienti da CDC USA: la mortalità anestetica legata
all’anestesia;cause e differenze fra AG e reg.
Il numero assoluto di morti materne da AG è
rimasto stabile negli anni 1979-1990.
I problemi di vie aeree sono la causa
principale di mortalità da AG,mentre il
numero assoluto di morti legate alla anest.reg.
è in calo dal 1984,equamente divise fra
tossicità da AL e anestesia spinale/perid alta.
Tuttavia sono diminuite le morti da tossicità da
AL da quando Food and Drug Administration
ha tolto l’approvazione per la bupivacaina
0.75% in ostetricia.

Complications of AG for C/S: CDC USA

20.0/milione GA ( 1979—1984)

32.3 morti/milione (1985—1990)


CS: mortalità per anest reg
CDC USA
8.6 /milioni di anest reg ( 1979—1984)

1.9 /milione ( 1985—1990).


Perché è possibile che ci sia ancora una mortalità + alta con
AG?

Perché negli ultimi anni non si fanno +
AG!!!
Paz + anziane
Paz + ammalate
Classi socioeconomiche meno
abbienti….immigrati…..


Instaurazione precoce della
analgesia(P.d.) in travaglio
In generale, eviterà la GA.
Permette la precoce scoperta di un catetere pd
“sospetto”,
……..
non tutte le anest reg sono in grado di portare a
termine il parto operativo;
» distress non anticipato intraop(dolore,emorragia massiva
intraop con instabilità emodinamica….)

GA:pro & contro
veloce
Alta % successo
Pieno controllo
Rilasc.uterino
(alog..)
Meno ipotens
Protez delle vie
aeree (ma nel
mentre….)

Probl. Con vie aeree
Aspirazione
Ipertens durante
laringoscopia e intubaz
Depressione cardiaca
Depressione resp
Depressione neonatale
“Awareness”


Anestesia regionale;pro &
contro
cosciente
Psicologico…
Legame
materno/fetale:
la madre si fa carico
immediatamente del
neonato…
No intubazione
Minor rischio di inalaz
Analgesia postop
Soddisfazione
materna

Tecnicamente +
difficile
Consumo di tempo
ipotensione


Indicazioni per AG (QCCH,Crowhurst 2001)

cord prolapse
sev.fetal distress
maternal request
failed reg
Reg contraindicated


Richiesta materna per AG
Ansietà
Pregressa esperienza:
cattiva(con reg)
» buona(con GA)
» dorsalgia

» Quando non vengono visitate nella
clinica preop o prenaest…….

Anesthesia for emergency C/S

Morgan et al.BJA 1990;97:420-24
“need for emergency C/S anticipated in
87% (380 cases).Early establishment of
epidural analgesia in labour allowed
extension to adequate anaesthesia in
70%”
Crowhurst(ESOA 2001);99% extension

Domande sull’emergenza

Epid in sede:quanto ci vuole dal
rifornimento ad un blocco adeg.per C/S?
Intervallo decisione-parto
Rischio fetale:quanto da AG e quanto
da reg?
Strategie che beneficino il feto……..


CESDI:Confidential Enquiry into Stillbirths and
deaths in infancy,7th report,2000
Composizione:
» OB anesthesia focus group
» 2 ob anesthesiologists
» 2 obstetricians

873 perinatal deaths;25(2,8%)anesth.contributing factors
identified:
»
»
»
»
»

maternal anaphylaxis1,
maternal bronchospasm and hypoxia 1,
failed/difficult oti 2
Delay with personnel 11
Delay in administering anesth 10


Ottimizzazione della fisiologia
materno fertale
1)Materna:
1)trasporto di O2
» 2)ventilazione
» 3)circolazione
» 4)flusso ematico uteroplacentare

5)flusso ematico ombelicale(fetal)

1-4 possono essere

ottimizzati


Listato dei punti di interesse
Profilassi ab ingestis
Posizionamento
Vena di calibro adeguato
Monitoraggio
Preossigenazione
Induzione
Manovra di Sellick
IOT
Mantenim :preparto
Mantenim post parto
estubaz

Valutazione preanestetica
Vie aeree

IOT:anestesisti e ostetrici…..

Gaiser RR, McGonigal ET, Litts P, et al: Obstetricians’ ability to assess the
airway. Obstet Gynecol 1999; 93(5 Pt 1):648–652

funzionalità cardiovascolare
funzionalità respiratoria
allergie

precarico?

stratificazione del rischio


Valutazione vie
aeree:Mallampati,Cormack etc


Test di protrusione mandibolare


Definito il rischio:
Raduna aiuto
prepara carrello intubazione difficile
procedi alla analgesia in travaglio(pd cont)
segui il parto
visita regolare dell’area travaglio e del reparto di
ostetricia; (Morgan BM, Magni V, Goroszeniuk T: Anaesthesia for emergency
caesarean section. Br J Obstet Gynecol 1990;97:420 & Morgan M: Anaesthetic
contribution to maternal mortality. Br J Anaesth 1987;59:842.)
PREVENZIONE DELLE EMERGENZE NELL 87% DEI CASI


Ricorso non necessario alla AG

Inadeguata educazione della paziente
abitudini chirurgiche
chiamata tardiva
controindicazioni sorpassate:
» preeclampsia
» placenta praevia
» febbre
» mal.cardiache

Prevenzione delle C/S di urgenza(Morgan,Brit J
Obstet Gynecol 1990;97:420)

visite preop congiunte 3 volte al dì
analgesia peridurale raccomandata per
tutte le madri a rischio di C/S
comunicazione continua fra reparto di
ostetricia e anestesia
…risoluzione dei problemi
organizzativi…...

Indicazioni per GA in OBS
Personale di anest con scarsa esperienza in reg
Rifiuto della reg da parte della paz
Paz non cooperante
Tutti i casi di controindicaz alla reg:
» Infez localizzata(dorso) vs generalizzata (sepsis)….
» Coagulopatia:
emergenza: distress fetale,placenta praevia, emorragia materna,
manovre ostetriche urgenti …….
ipovolemia….
Certe cardiopatie che non possono tollerare ipotens:CO fisso,per
es,stenosi aortica severa,Eisenmenger

Parekh N,Husaini SWU,Russell IFCaesarean section for
placenta praevia:a retrospective study of anesthetic
management.Br.J.Anaesth. 2000;84:723-30.

All anesth from 1 genn 1984 to 31/12/1998.
350 cases of plac previa:
» 60% Reg / 40% AG
» plc accreta;7 cases; 4 REG , 3 AG:but 2 reg convert.to
AG…5 hysterect.
» PA control during haemorrhage not a problem
» RA assoc.with less blood loss
» “This retropective study do not support the often quoted
motto that plac.praevia calls for AG….”.

Svantaggi della AG
Paz addormentata e inconscia:legame materno neonatale più
tardivo…
Marito meno probabile sia presente in sala op
Depressione fetale da farmaci
Risposta da stress all’IOT
Aum morbilità postop
Modificaz cardiovasc all’intubaz
Pericolo di inalazione (intubaz & estubaz…)
Intubaz difficile
Dati di mortalità;CEMDUK,USA,ecc.

AG:tecnica :I
Premed;antiacidi /H2 bloccanti/citrato di sodio
LUD:
» Manuale,inclinazione del leto,cuneo sotto anca dx….

ID/ UI-D intervalli + brevi possibile
preO2
(precurarizzazione)????
induzione
“cricoid pressure”
Succi odicuraro del giorno? Ospedale di Faenza(RA)
Servizio Anestesia e Rianimazione

AG:tecnica:II
IOT
Controlla espansione polm,bilat.
N20 50% + halog 0.6 Mac
Dopo parto:ripeti ipnotico + analgesico;stop volatile
Ossitocina 10-20 UI/lt,drip…:lentamente!!!
Estubare solo se sveglia e cooperante,assicurandosi
della piena ripresa nm …
Pianificare per la fallita intubazione

Posizione della paziente
Prevenire la compressione aorto-cavale
seduta:+ facile per le obese
laterale;meglio per le presentazioni
podaliche con membrane rotte


Posizione
LUD;spostamento uterino a sn
LLT;tilt laterale del letto a sn
Trendelemburg lieve?
» Implicazioni per rigurgito…..

Posizione ottimale per IOT:”Sniffing
position”
“orecchie sopra le spalle”

Monitoraggio
Appropriato per ogni sala op. di chirurgia addominale:
NIBP(ogni 1-2 min);ECG;SaO2,etCO2,TV,Paw,RR,N2O,alog…..

disponibilità di infusori rapidi di liquidi caldi
possibilità monitoraggio PA continua cruenta e PVC
possibilità di CO continuo….
Continuazione del monitoraggio fetale durante induzione
dell’anestesia e la preparazione chirurgica dell’addome…….


Capnometria sidestream
Ossigenazione e FiO2


Ossigenazione /
preossigenazione


Benumof JL Critical hemoglobin saturation will occur before
return to an unparalyzed state following 1 mg/kg intravenous
succinylcholine.Anesthesiology 1997;87:979.


Tempo di apnea fino al raggiungimento di una SaO2
specifica in pazienti in AG con confronto tratto da un
modello matematico


Frequenza di iot fallite

16 anni di esperienza del St James
5802 GA per C/S
0.4% di iot fallite;1/300 1984,1/250
1994.
» , L.; Hawthorne Wilson, R.; Lyons, G.; Dresner,
M. Failed intubation revisited: 17-yr experience
in a teaching maternity unit
» Br. J. Anaesth. 1996; 76:680-684.

Frequenza di iot fallite(Tsen et al,Int J.Obset Anesth. 1998;7:147)

16
14
12
10
% 8
6
4
2
0

1990
1991
1992
1993
1994
1995

iot fallite

Cause delle iot difficili

Variazioni anatomiche
fattori organizzativi:
» inesperienza
» urgenze fuori orario
» “stat” mentalità
» panico

Iot fallite e tipo di C/S(Hawthorn,BJA
1996
90
80
70

60
50
%
40
30
20
10
0

% AG
fallite

ele ttive

e me rgenza


Il Mallampati varia durante il
travaglio!!!
Farcon EL.,Kim MH,Marx GF. Changing
Mallampati score during labour Canadian Journal
of Anaesthesia. 41(1). 1994. 50-51.
» Primigravuida sana
» All’ingresso:Mallampati 1-2
» A 8 cm di dilatazione:Mallampati 3-4(edema
dell’ipofaringe)
» Immediato postpartum:Mall;3-4
» 1 H postpartum:Mall 1-2.

Aumento delle iot difficili in ostetricia
1.8
1.6
1.4

%

1.2
1

chir gen
C/S (Pilk)
C/S (Durban)
ost (Carli)

0.8
0.6
0.4
0.2
0

score 3


Manovra di Sellick


of an effective cricoid pressure. Anaesthesia 1983; 38:461-466.

44 Newton= 4.5 kg


Brimacombe JR,Berry AM.Cricoid pressure .Can J
Anaesth 1997 ; 44: 414-425
Purpose: Although cricoid pressure (CP) is a superficially simple and appropriate
mechanical method to protect the patient from regurgitation and gastric insufflation, in
practice it is a complex manoeuvre which is difficult to perform optimally. The purpose of this
review is to examine and evaluate studies on the application of (CP). It deals with anatomical
and physiological considerations, techniques employed, safety and efficacy issues and the
impact of CP on airway management with special mention of the laryngeal mask airway.
Source of material: Three medical databases (48 Hours, Medline, and Reference Manager
Update) were searched for citations containing key words, subject headings and text entries
on CP to October 1996.
Principle Findings: There have been no studies proving that CP is beneficial, yet there is
evidence that it is often ineffective and that it may increase the risk of failed intubation and
regurgitation. After evaluation of all available data, potential guidelines are suggested for
optimal use of CP in routine and complex situations.
Conclusions: If CP is to remain standard practice during induction of anaesthesia, it must be
shown to be safe and effective. Meanwhile, further understanding of its advantages and
limitations, improved training in its use, and guidelines on optimal force and method of
application should lead to better patient care.


Evidenza a vantaggio della manovra di
SELLICK


Evidenza contraria alla manovra di
SELLICK


Gruppi di pazienti a rischio da una manovra di Sellick
inappropriata


Carrello per intubazione

In sala op.
laringoscopi:manico normale,sottile ,corto
lame curve,rette,Bizzarri,ecc
Guedel,Copa
LMA di vari calibri
mandrino di gomma,con ventilazione
set crico tiroidotomia:Patil,Ravussin,ecc
fibroscopio……..
jet ventilation……...


Hawthorne L,Wilson, R.; Lyons, G.; Dresner, M. Failed
intubation revisited: 17-yr experience in a teaching maternity
unit .Br. J. Anaesth. 1996; 76:680-684


Gataure PS,Hughes JA.The laryngeal mask airway in
obstetrical anaesthesia.Report of Investigation. CAN J
ANAESTH 1995 / 42: 2 / pp130-3

questionario sull’utilizzo della LMA in caso di
difficile o fallita intubaz in ostetricia
240 consultant in anestesia UK
72% favorevoli
10% con esperienza personale
2,5% asseriscono che la LMA ha salvato la
paziente
Opinione generale che debba essere usata prima
della cricotiroidotomia

LMA in ostetricia
1. McClune S, Regan M, Moore J. Laryngeal mask airway for caesarean section. Anaesthesia 1990;45:227–8
2. de Mello WF, Kocan M. Further options for obstetric anaesthesia. Br J Hosp Med 1989;42:426.
3. Storey J. The laryngeal mask for failed intubation at caesarean section. Anaesth Intensive Care 1992;20:118–9
4. Christian AS, McClune S, Moore JA. Failed obstetric intubation. Anaesthesia 1990;45:995.
5. Chadwick LS, Vohra A. Anaesthesia for emergency Caesarean section using the Brain laryngeal mask airway.
Anaesthesia 1989;44:261–2.
6. Lim W, Wareham C. The laryngeal mask in failed intubation. Anaesthesia 1990;41:689–90.
7. Priscu V, Priscu L, Soroker D. Laryngeal mask for failed intubation in emergency Caesarean section. Can J Anaesth
1992;39:893.
8. Hasham FM, Andrews PJD, Juneja MM, Ackermann III WE. The laryngeal mask airway facilitates intubation at cesarean
section: a case report of difficult intubation. Int J Obstet Anesth 1993;2:181–2.
9. McFarlane C. Failed intubation in an obese obstetric patient and the laryngeal mask. Int J Obstet Anesth 1993;2:183–4.
10. Vanner RG. The laryngeal mask in the failed intubation drill. Int J Obstet Anesth 1995;4:191–2.
11. Brimacombe J. Emergency airway management in rural practice: use of the laryngeal mask airway. Australian J Rural
Health 1995;3:10–9.
12. de Mello WF, Kocan M. The laryngeal mask in failed intubation. Anaesthesia 1990;41:689–90.
13. Godley M, Ramachandra AR. Use of LMA for awake intubation for Caesarean section. Can J Anaesth 1996;43:299–
302.
14. de Mello WF, Restall J. Difficult intubation. Can J Anaesth 1990;37:486.
15. Davies JM, Weeks S, Crone LA. Failed intubation at caesarean section. Anaesth Intensive Care 1991;19:303.
16. Shung J, Avidan MS, Ing R, et al. Awake intubation of the difficult airway with the intubating laryngeal mask airway.
Anaesthesia 1998;53:645–9.
17. Hawthorne L, Wilson R, Lyons G, Dresner M. Failed intubation revisited: 17-yr experience in a teaching maternity unit.
Br J Anaesth 1996;76:680–4.
18. Gataure PS, Hughes JA. The laryngeal mask airway in obstetrical anaesthesia. Can J Anaesth 1995;42:130–133.
19. White A, Sinclair M, Pillai R. Laryngeal mask airway for coronary artery bypass grafting. Anaesthesia 1991;46:234.


LMA Proseal
Han TH, Brimacombe J, Lee EJ, Yang HS. The laryngeal mask airway is effective and
probably safe in selected healthy parturients for elective Cesarean section. Can J
Anaesth 2001;48:1117–21.
Awan R, Nolan JP, Cook TM: Use of a ProSeal laryngeal mask airway for airway
maintenance during emergency caesarean section after failed tracheal intubation. Br J
Anaesth 2004; 92:144–146
Brown NI, Mack PF, Mitera DM, et al: Use of the ProSeal laryngeal mask airway in a
pregnant patient with a difficult airway during electroconvulsive therapy. Br J Anaesth
2003; 91:752–754
Bullingham A: Use of the ProSeal laryngeal mask airway for airway maintenance
during emergency caesarean section after failed intubation. Br J Anaesth 2004; 92:903
Keller C,Brimacombe J,Lirk P,Pühringer F.Failed Obstetric Tracheal Intubation and
Postoperative Respiratory Support with the ProSeal™ Laryngeal Mask Airway
]


Conclusioni sulla intubazione difficile

Mettere a punto
l’organizzazione;informazione,visite,educazione,Sell
ick…...
valutare le vie aeree
adottare una pratica che sottolinei l’ossigenazione
ed il risveglio della madre
praticare regolarmente !
evitare l’AG.

Intubazione
Adiuvanti:
NMB:
» Succi 1-1.5 mg/kg
» Rocuronium 1.2 mg/kg(60”)-0.6 mg/kg(80”)
– Abouleish E, Abboud T, Lechevalier T, Zhu J, Chalian A, Alford
K. Rocuronium (Org 9426) for Caesarean section. British
Journal of Anaesthesia 1994; 73:336-341.

» Vecuronium 0.2 mg/kg
» ???
» Atracurium peggio della DTC per il neonato

Perreault C,Guay J,Gaudreault P,Cyrenne L,Varin F.Residual
curarization in the neonate after cesarean section.Can
J.Anesth 1991;39:587
– ABSTRACT: The transplacental transfer and the neonatal effects of atracurium 0.3 mg × kg-1
(ED95) were compared with those of d-tubocurarine at the usual clinical dose of 0.3 mg × kg-1
(ED90) in 46 patients undergoing elective Caesarean section. The atracurium group (25 patients)
was similar to the d-tubocurarine group (21 patients) as far as age, parity and time intervals
between precurarization, induction, skin incision, muscle relaxant administration, hysterotomy and
birth. The transplacental transfer of atracurium was lower than that of d-tubocurarine, with a fetomaternal ratio of 9 ± 3% for atracurium and 12 ± 5% for d-tubocurarine (P < 0.05). The
transplacental transfer of laudanosine was low at 14 ± 5%, with blood levels of 0.101 ± 0.032 mM
× L-1 in the umbilical vein. Newborns in the two groups were comparable in terms of Apgar
scores at one, five and ten minutes, as well as for NACS scores (neurological and adaptive
capacity scoring test) at two and 24 hours after birth. However, at 15 min after birth, only 55% of
newborns in whom the mothers received atracurium had a normal NACS score (³ 35/40)
compared with 83% of newborns in whom the mothers received d-tubocurarine (P < 0.05).
Further analysis of the five variables related to active muscle tone revealed that the modal score
for active extension of the neck of newborns from the atracurium group was lower
than for newborns from the d-tubocurarine group (P < 0.01). This was compatible with the effect
of residual curarization among newborns in whom the mothers received atracurium. However, this
effect was transient since there was no difference found between the two groups at two and 24 hr
after birth. Furthermore, no newborn had clinical signs of respiratory distress. In conclusion,
atracurium given at a dose of 0.3 mg × kg-1 for Caesarean section may lead to partial residual
curarization of neonates 15 min after birth.


Fattori di rischio associati alla intubazione tracheale difficile

(da

Rocke DA, Murray WB, Rout CC, Gouwns E: Relative risk analysis of factors associated
with difficult intubation in Obstetric anesthesia. Anesthesiology 1992; 77:67 ‑73.)

Caratteristica
anatomica
» Mallampati 4
» mandibola recedente
» protrusione incisivi
mascellari
» Mallampati 3
» Collo corto
» Mallampati 2
» Mallampati 1

Rischio relativo
» 11.30
» 9.71
» 8.00

» 7.58
» 5.01
» 3.23
» 1.00

FiO2
– Piggott SE, Bogod DG, Rosen M, Rees GAD:
Isoflurane with either 100% oxygen or 50%
nitrous oxide in oxygen for cesarean
section. Br J Anaesth 61:255, 1990
– 34 Bogod DG, Rosen M, Rees GAD: Maximum
Fi02 during cesarean section. Bir J Anaesth
61:255,1988


Khaw, K S.; Wang C C, Kee W D. Ngan Pang C P, Rogers,
M.S.Effects of high oxygen inspired fraction during electice
caesarean section under spinal anesthesia on maternal and fetal
oxygenation and lipid peroxidation.BJA 2002;88:18-23


Ossigenazione
O2 50% + N2O 50% vs O2 100%:
» UvpO2 + alta di 6-7 torr;pH o BD no diff!
– Bogod BJA 1988,PIGGOTT BJA 1989

» Se si aum FiO2,aumenta anche il vapore!!!
» Aumentare la FiO2 nell’intervallo IU-D non
porta aumenti nella ossigenazione fetale(poco
tempo??)
» Perreault, C., Blaise, G. A; Meloche, R..
» Maternal inspired oxygen concentration and fetal oxygenation
during cesarean section.Can.Anesth.Soc.J.1992 ;39:155

Kee WD Ngan, Khaw KS,Ma KC,Wong ASY, Lee B.
Randomized double blind comparison of different oxygen
inspired fractions during general anesthesia for cesarean
section.BJA 2002;89:556.
We randomized patients having elective Caesarean section to receive one of the following:
FIO2 0.3, FIN2O 0.7 and end-tidal sevoflurane 0.6% (Group 30, n=20); FIO2, 0.5, FIN2O 0.5
and end-tidal sevoflurane 1.0% (Group 50, n=20), or FIO2 1.0 and end-tidal sevoflurane 2.0%
(Group 100, n=20) until delivery. Neonatal outcome was compared biochemically and
clinically.
Results. At delivery, for umbilical venous blood, mean PO2 was greater in Group 100 (7.6
(SD 3.7) kPa) compared with both Group 30 (4.0 (1.1) kPa, P<0.0001) and Group 50 (4.7
(0.9) kPa, P=0.002) and oxygen content was greater in Group 100 (17.2 (1.6) ml dl-1)
compared with both Group 30 (12.8 (3.6) ml dl-1, P=0.0001) and Group 50 (13.8 (2.6) ml dl-1,
P=0.0001). For umbilical arterial blood, PO2 was greater in Group 100 (3.2 (0.4) kPa)
compared with Group 30 (2.4 (0.7) kPa, P=0.003), and in Group 50 (2.9 (0.8) kPa) compared
with Group 30 (2.4 (0.7) kPa, P=0.04); oxygen content was greater in Group 100 (10.8 (3.5)
ml dl-1) than in Group 30 (7.0 (3.0) ml dl-1, P<0.01). Apgar scores, neonatal neurologic and
adaptive capacity scores, and maternal arterial plasma concentrations of epinephrine and
norepinephrine before induction and at delivery were similar among groups. No patient
reported intraoperative awareness.
Conclusions. Use of FIO2 1.0 during general anaesthesia for elective Caesarean section
increased fetal oxygenation.



FiO2

FiN2O

Sevoflurane
%

0.30

0.70

0.6

0.50

0.50

1

1

0

2


Ossigenazione(e awareness)
FiO2 1:UV pO2> FiO2 0.50(Bogod et
al.Br.J.Anaesth 1988;61:255-62 per AG .e Ramanathan Anesth
Analg 1982;61:576-81. per analg p.d.

se N2O 50% ,MAC 0.5 -0.7
se FiO2 1,MAC 1.2:quindi:
» haloth 1.1 *5 min,poi 0.75
» enflur 2.5 * 5 min,poi 1.7
» isofl 1.8 * 5 min,poi 1.2
» sevor 2.2 * 5 min,poi 1.5

Perreault, C., Blaise, G. A; Meloche, R. Maternal
inspired oxygen concentration and fetal oxygenation
during cesarean section.Can.Anesth.Soc.J.1992 ;39:155.
»
» This study was designed to determine whether fetal arterial and venous PO2
could be increased by increasing maternal FIO2 in the period between
hysterotomy and birth. Two groups of ten patients were studied. All were
anaesthetised with the same technique except for the FIO2 after
hysterotomy. One group inspired 50% oxygen and the second group inspired
100% oxygen. Although the maternal arterial PO2 was higher at birth in the
100% O2 group (177.4 ± 42.3 mmHg vs 281.0 ± 94.2 mmHg), there were no
differences between the arterial umbilical cord PO2 (19.3 ± 5.7 mmHg vs 18.5
± 7.3 mmHg) and the venous umbilical cord PO2 (31.1 ± 7.6 mmHg vs 33.0 ±
10.8 mmHg). Awareness was present in one patient in the 50% O2 group and
in four patients in the 100% O2 group but this difference was not statistically
significant. It is concluded that a higher inspired maternal oxygen
concentration between hysterotomy and birth does not result in any increase
in fetal PO2.


Mantenimento AG Postpartum
N2O/O2 66/33,70/30…….
Alogenato????(atonia uterina!!!)
Amnesia
» (diazepam 5-10 mg,midazolam 2-5 mg)

Analgesia:morfina 0.2-0.3
mg/kg,fentanile 2-3 microgr /kg
Ripetere ipnotico

Bilancia dell’AG

Anestesia materna

Minima depressione neonatale


Indicazioni per gli
anest.alogenati
Potenziamento della AG:riduzione
delle catecolamine materne……
Crawford??

Riduzione o eliminazione della
sensazione di veglia materna:paziente
addormentata e inconscia
Condizioni operative ottimali


Effetti collaterali
Alterazioni emodinamiche
Atonia uterina…


Vantaggi degli alogenati
Permettono alte FiO2
Possono aum il flusso ematico uterino diminuendo la
vasocostrizione delle art uterine mediata dalle
catecolamine materne
Previene l’ awareness…ma sono necessari alcuni
min prima di ottenere un MAC ragionevole (sevoflurane
o desflurane equilibrano + rapidamente


Svantaggi degli alogenati
Sanguinam. uterino
Bassi punteggi di Apgar?
Bassi punteggi nelle
valut.neurocomportamentali
Inquinamento ambientale


Modificazioni indotte dalla gravidanza
che influenzano l’anest inalatoria
Soglia per dolore e fastidio
MAC richieste :25%‑40%
» Datta et al,Chronically administered progesterone decreases
halothane requirements in rabbits.Anesth.Analg. 1989;68:46-50) .

FRC


Chan et al.
Minimum Alveolar Concentration of Halothane and
Enflurane Are Decreased in Early Pregnancy Anesthesiology
85:782-6, 1996


Riduzione MAC in gravidanza

Gin T, Chan MTV: Decreased minimum alveolar concentration of isoflurane in pregnant humans.
ANESTHESIOLOGY 81:829-32, 1994 ;
Chan et al.
Minimum Alveolar Concentration of Halothane and Enflurane Are Decreased in Early Pregnancy
Anesthesiology 85:782-6, 1996

1,8
1,6
1,4
1,2
1
0,8

isoflurane
halothane
enflurane

0,6
0,4
0,2
0

non pregnant

pregnant


Gin T, Chan MTV: Decreased minimum alveolar
concentration of isoflurane in pregnant humans.
ANESTHESIOLOGY 81:829-32, 1994
Minimum alveolar concentration (MAC) is decreased in pregnant animals, but this change has
not been demonstrated in humans, probably because of ethical considerations. It is less
problematic to determine MAC in pregnant women undergoing termination of pregnancy,
however, and therefore we compared the MAC of isoflurane in these women with the MAC in
matched nonpregnant women. METHODS: Patients underwent inhalational induction of
anesthesia with isoflurane and tracheal intubation. MAC was determined in each patient by
testing the response to a 10-s, 50-Hz, 80-mA transcutaneous tetanic electrical stimulus to the
ulnar nerve at varying concentrations of isoflurane. The end-tidal concentration of isoflurane
was kept constant for 10 min before each stimulus and the concentration of isoflurane
ultimately varied in steps of 0.05% until we obtained a sequence of three alternate responses
(move, not move, move) or (not move, move, not move). MAC for each patient was taken as
the mean of the two concentrations just permitting and just preventing movement. MAC for the
group was taken as the median of the individual MAC values. A blood sample was taken
immediately before induction of anesthesia for measurement of progesterone concentrations.
Data were compared between groups by the Mann-Whitney test. RESULTS: The median
(range) MAC for isoflurane in the pregnant group, 0.775% (0.675-0.825), was less than that in
the nonpregnant group, 1.075% (1.025-1.175) (P < 0.001). The median (range) plasma
progesterone concentration in the pregnant group, 63.4 (0.8-106) nM, was greater than that in
the nonpregnant group, 8.4 (0.7-66) nM (P < 0.02). CONCLUSIONS: The MAC of isoflurane

Chan M,Mainland P, Gin T
Minimum Alveolar Concentration of Halothane and
Enflurane Are Decreased in Early Pregnancy Anesthesiology
85:782-6, 1996
The MAC of halothane and enflurane were compared in pregnant women undergoing elective
termination of pregnancy and in nonpregnant women.
Methods: We studied 16 pregnant women scheduled for termination of pregnancy at 8 to 13
weeks gestation and 16 nonpregnant patients undergoing laparoscopic sterilization. Eight
patients in each group received halothane and the others received enflurane. After inhalational
induction of anesthesia and tracheal intubation, MAC was determined in each patient by
observing the motor response to a 10-s, 50-Hz, 80-mA transcutaneous electric tetanic stimulus
to the ulnar nerve at varying concentrations of either halothane or enflurane. The end-tidal
concentration of inhalational anesthetic was kept constant for at least 15 min before each
stimulus and the concentration was varied ultimately in steps of 0.05 vol% (halothane) or 0.10
vol% (enflurane) until a sequence of three alternate responses (move, not move, move) or (not
move, move, not move) was obtained. Minimum alveolar concentration for each person was
taken as the mean of the two concentrations just permitting and just preventing movement, and
MAC for the group was the median of individual MAC values. Confidence intervals were
calculated for the percentage decrease in MAC for pregnant women compared with nonpregnant
women.
Results: The median (range) MAC of halothane, 0.58 vol% (0.53 to 0.58), and enflurane, 1.15
vol% (0.95—1.25), in the pregnant women were less than those in the nonpregnant women, 0.75
vol% (0.70 to 0.78), P = 0.0005 and 1.65 vol% (1.45 to 1.75), PFaenza(RA)
Servizio di Anestesia e Rianimazione Ospedale di = 0.0007, respectively. The

Avoid maternal
hyperventilation


Conseguenze della iperventilazione materna
(da Shnider,Moya,Levinson,Cosmi…)


King H, Ashley S, Brathwaite D, Decayette J,
Wooten D: Adequacy of general anesthesia for
cesarean section. Anesth Analg 77:84-8, 1993

68-130 sec

3min

2min

inc

1 min

ind

skin inc

Lifescan
finger flexion
hand squeeze
lacrimation

lryngoscopy,IOT

120
100
80
% of
60
patients
40
20
0

Isolated arm technique

delivery
220-367 sec.

Tps/scc/iot/N2O 50/haloth 0.5%


Characteristics of inhaled
anesthetics
agent

mw

MAC

Boling
point

Vapor
press.

Blood/gas
partition
coeff.

pungency

Soda lime

desflur
ane

168

6

23.5

663

0,42

yes

stable

N2O

44

105

-88

no

stable

sevoflu
rane

200

2.0

58.5

39000 0,47
gas
160
0,60

no

decomposes

isoflura
ne

184,5

1.15

48.5

238

moder Stable
ate
moder Stable
ate
none Decomposes

1.4

enflura 184,5 1,68
56.5
175
1,9
ne
halotha 197,4 0,75
50,2
241
2,4
ne Servizio di Anestesia e Rianimazione Ospedale di Faenza(RA)

Rapidità della crescita della concentrazione alveolare
(Fa)di anestetico in relazione alla concentrazione
inspirata (Fi)


Navarro EM.Desflurane general anesthesia for cesarean
section compared with isoflurane and epidural
anesthesia.Anesthesiol.Intensivmed.Notfallmed.Schmerzther
2000;35;232-6.

Desflurane 2.5% vs isofl 0.5% vs epid 15 ml ropi
0.75% + fent 100 microgr
N2O 50%
intraop haemodynamics
blood loss
maternal awareness
Apgar scores 1-5 min
NACS 2-24 h
Ega UV/MV

Navarro II
No diff among the 3 groups except
a more rapid emergence following
des.


Olthoff D,Rohrbach A. Sevoflurane in obstetric
anesthesia.Anesthesist 1998;47,suppl 1,s 63-9

Sevo > isofl and no outcome diff with
epid,
sevo> isof in pEEG monitoring……...


Attenuazione della risposta
catecolaminica


Shnider et al: Uterine blood flow and plasma norepinephrine
changes during maternal stress in the pregnant ewe.
ANESTHESIOLOGY 50:524-7, 1979
Electrically induced stress 30-60 sec,
loud noises,sudden movement of personnel...

60
40
20
% change
from
basal

0
-20

1

2

3

4

5

-40
-60
-80
min


MAP
Norepi
uter.Blood flow

Modificazioni del flusso ematico uterino durante
anestesia nella scimmia gravida (from
20
15
10
5
% change from
0
control
-5
-10
-15
-20

Shnider,Levinson,etc..)

N2O 50%
N2O 50% +haloth 0.5%
N2O 50% + enfl 1%

anest without stim

anest with
stimulation


Maternal awareness of surgery and birth
after barbiturate-relaxant induction &...
20
18
16
14
12
% 10
8
6
4
2
0

N2O 50%
N2O 67-75%
N2O 25-40%+halo
0.4%
N2O 50%+haloth
0.3%
N2O 50%+enfl 0,75
N2O 33%+metx 0.1%
maternal awareness

N2O 50+ isof 0,75%


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

1982-1989
> 3000 patients
questioned about recall and dreaming after GA for
C/S 28 (0.9%) patients were able to recall something
of their operation
189 (6.1%) reported dreams. Recollections of surgery
were confined to manipulations, noises and voices.
None of our patients complained of pain at the time of
interview, although one since has.

Incidenza della awareness(from
various sources)

16
14
12
10

C/S
card.surg
non card. Surg
major trauma

% 8
6
4
2
0

0.4
incidence


Domino K, Posner KL, Caplan, R,Cheney F. Awareness
during Anesthesia : A Closed Claims analysis.Anesthesiology
90:1053-61, 1999.

Liability risk
Rischio della responsabilità


Dwyer R, Bennett HL, Eger EI II, Peterson N: Isoflurane
anesthesia prevents unconscious learning. Anesth Analg
75:107-12, 1992

Parecchi autori riportano che la prevenzione del
ricordo cosciente di eventi si ottiene con
concentrazionei relativamente basse di anestetici
volatili .
Isoflurane 0.6 MAC previene il ricordo conscio

e l’apprendimento incosciente di
informazioni fattuali e i suggerimenti
comportamentali

Moir, D. D .ANAESTHESIA FOR CAESAREAN SECTION An
Evaluation of a Method using Low Concentrations of Halothane
and 50 per cent of Oxygen Br. J. Anaesth. 1998; 80:690-696
The addition of 0.5 per cent of halothane vapour to a basic
thiopentone, nitrous oxide, muscle relaxant anaesthetic
technique does not increase blood loss at Caesarean section,
does not affect the incidence of hypotension, and is likely to
ensure unconsciousness. By permitting the administration of
50 per cent of oxygen with nitrous oxide, the condition of the
newborn infant is likely to be improved. The use of 0.8 per
cent of halothane vapour does not increase blood loss but is
associated with a high incidence of hypotension and for this
reason is not advisable.

Eger, Edmond I, II,.Age, Minimum Alveolar Anesthetic
Concentration, and Minimum Alveolar Anesthetic
Concentration-Awake .Anesthesia & Analgesia 2001; 93:947953

MAC-Awake is also close to the anesthetic
concentration suppressing memory and
learning

» Dwyer R, Bennett HL, Eger EI, Heilbron D. Effects of isoflurane and nitrous
oxide in subanesthetic concentrations on memory and responsiveness in
volunteers. Anesthesiology 1992; 77:888-98.
» Dwyer R, Bennett HL, Eger EI, Peterson N. Isoflurane anesthesia prevents
unconscious learning. Anesth Analg 1992; 75:107-12.
» Chortkoff BS, Bennett HL, Eger EI. Subanesthetic concentrations of isoflurane
suppress learning as defined by the category-example task. Anesthesiology
1993; 79:16-22.
» Chortkoff BS, Gonsowski CT, Bennett HL. Subanesthetic concentrations of
desflurane and propofol suppress recall of emotionally charged information.
Anesth Analg 1995; 81:728-36.


MAC AWAKE

End-tidal anaesthetic concentrations at first eye opening in response to a verbal command during recovery from
anaesthesia
MAC-Awake, the end-tidal anesthetic concentration at 1 atm that suppresses the appropriate response to
command in 50% of subjects.

Autori

Rivista/anno

MAC

MAC awake

GAUMANN

Br. J. Anaesth.
1992; 68:81-4

Isof 1.2

0.30%=0.25 Mac

Haloth 0.8

0.45%=0.50/0/59
mac

Enflurane 1.7

0.45%=0.27 mac

Sevo

0.61%=0.33 mac

ISOf

0.39%=0.33 mac

isof

0.41%

KATOH

Br. J. Anaesth.
1992; 69:259-62

Suzuki

Anesth Analg 1998;
86:179–83

sevoflurane

0.7%

Katoh

Anesth Analg 1993;
76:348–52

sevo

0.62%


Outcome dopo GA


C/S elettivi:Durata della GA o Epidurale antepartum e % di
Apgar tra 7-10

100
90
80
70
60
% 7-10
50
Apgar scores
40
30
20
10
0

(da dati di Robin,Shnider,Levinson---)

Min:
<5
6;10
11;20
21;30
31;60
GA

epid


I-D & UI-D
Ma + importante che la durata totale fra
induzione e parto (I-D) ,quello critico è
L’ intervallo incis.uterina /parto (UI-

D),che ha dimostrato correlazione con
la ipossia fetale e l’acidosi


GA e depressione del neonato
100
90
80
70
60
50
40
30
20
10
0

spinal
epidural
GA

Apgar 1'

Apgar 5'


Efetti fetali e neonatali degli
alogenati
Maggiore frequenza di
resuscitazione neonatale
dopo AG vs regionale
» ONG BY,Cohen MM,Palahniuk
RJ:Anesthesia for cesarean section:
effects on neonates.Anesth.Analg
1989;68:270-275.

Ong BY,Cohen MM,Palahniuk RJ.Anesthesia for cesarean
section:effects on neonates.AA 1989;68:270-5.

3940 C/S;12.5% of neonates Apgar < 4
1.5% 5 min Apgar score < 4
Lista dei fattori associati con bassi punteggi di Apgar
a 1 min
» primiparià
» grande multiparità
» Patologie antepartum (preeclampsia,diabetes mellitus,mal cardiache materne,
isoimmunizzazione RH , emorragia precoce amtepartum)
» Presenza di fetal distress
» Bassa età gestazionale
» Uso di narcotici durante travaglio
» Presentazione podalica
» C/S non elettivo


Ong et al.Anesthesia for cesarean
section:effects on neonates.AA 1989;68:270-5.

Una analisi multivariata che ha
controllato per molte variabili ha dato :
Rischio + alto per bassi valori di Apgar a
1 min GA 3 >reg(2.5-3.88)
Rischio + alto per bassi valori di Apgar a
5 min; GA 3> reg(1.81-7)
Necessità di resuscitazione : GA 2>
reg(1.32-2.90)

Destino del neonato dopo C/S a seconda della tecnica
anestetica:piccoli con 1 min Apgar < 4 (%)
Ong BY,Cohen MM,Palahniuk RJ.Anesthesia for cesarean section:effects on
neonates.AA 1989;68:270-5.

0.01

45
40
35
30
25

0.001

20
15
10

0.05

5
0

elective
fetal distress
failure to progress

reg

GA


Piccoli con 5 min Apgar 0-4(%)
Ong BY,Cohen MM,Palahniuk RJ.Anesthesia for cesarean section:effects on neonates.AA
1989;68:270-5.

9

0.01

8
7
6
5

0.01

4
3

elective
fetal distress
failure to progress

2
1
0

reg

GA


Neonati che hanno necessitato O2 per maschera

Ong BY,Cohen MM,Palahniuk RJ.Anesthesia for cesarean section:effects on neonates.AA
1989;68:270-5.

0.001

25
20

0.01

15

elective
fetal distress
failure to progress

10
5
0

reg

GA


Neonati che hano richiesto iot e IPPV(%)

Ong BY,Cohen
MM,Palahniuk RJ.Anesthesia for cesarean section:effects on neonates.AA 1989;68:270-5.

45,0

0.001

40,0
35,0
30,0

elective
fetal distress
failure to progress

25,0
20,0
15,0
10,0
5,0
0,0

reg

GA


Morti neonatali
Ong BY,Cohen MM,Palahniuk RJ.Anesthesia for cesarean section:effects on
neonates.AA 1989;68:270-5.

7
6
5
4

elective
fetal distress
failure to progress

3
2
1
0

reg

GA


Gregory FA, Wagde JG, Biehl DR, Ong BY, Sitar DS. Foetal anaesthetic
requirements (MAC) for halothane. Anesth Analg 1983;62:9 ‑ 14.
Bachman CR, Biehl DR, Sitar DS, Cumming M, Pucci W. Isoflurane potency and
cardiovascular effects during short exposures in the foetal lamb. Can Anaesth Soc
J 1986;33:41‑ 7.

MAC è significativamente più basso nei feti
agnelli che nei neonati agnelli > 24 h di età.
» Questi dati suggeriscono che i neonati subito dopo il
parto possono essere particolarmente sensibili agli
anest.inalatori ,per cui quelli esposti agli anest.generali
possono essere meno vigorosi alla nascita .Dopo avere
assistito la respirazione e l’espirazione degli anest
inalati questi infanti sono simili agli altri


La depressione della contrattilità
uterina da alogenati sub Mac
ripercussioni cliniche sulle
perdite ematiche?

Postpartum blood loss:Piggott SE,Bogod DG,Rosen M,Rees
GAD,Harmer M.Isoflurane with either 100% oxygen or 50%
nitrous oxide in oxygen for caesarean section.BJA 1990;65:32529.
0.0
-5.0
HB decrease,
%

-10.0
elective
emergent

-15.0
-20.0
-25.0

N2O
50+haloth
0.5

O2100%+
haloth 0,75

02 100% +
enflur 1,7

02 100% +
isofl 1,2%


Influenza dell’anestesia sulle perdite ematiche nel C/S(Moir
DD.Anesthesia for cesarean section:an evaluation of a method using low concentrations of
halothane and 50% of oxygen.BJA 1970;42:136-142.

800
700
600
500

N2O 70
N2O50+ aloth 0,5
N2O 50+ haloth 0,8
epid analg

ml 400
300
200
100
0

blood loss


HCT :valori prima e dopo C/S
:(from Thirion et al.Maternal blood loss associated with low dose alothane administration
for caesarean section.Anesthesiology 1988;69:a693)

40
35
30
25
%

Hct preop
HCTday 1
Hct day 2

20
15
10
5
0

haloth
predelivery

aloth pre& post

epidural


Conclusioni sugli alogenati e
le perdite ematiche
Decremento nella contrattilità e tono uterino dose
dipendente
Ma nessun incremento nelle perdite ematiche se
somministrati in concentrazioni basse/moderate:

haloth 0.1-0.8
enflurane 0,5-1,5
isoflurane 0,75
Sevoflurane 0.8-1.5…..

In ogni caso;dopo il parto …...
Stop l’anest volatile
continua N2O(aum al 60-65%)
Somministra una II dose di ipnotico (TPS
100-150 mg;propofol 60-100 mg +
Un potente analgesico :fentanyl 100-150
microgr..…
nmb se necessari……


Interazioni degli anest volatili
con:
Potenziamento dei miorilassanti
nifedipina;
» aum degli eff,coll. con aloth,enfl,isof( ma non su animali gravidi)
– Rosone et al..Hemodynamic responses to nifedipine in dogs anesthetized
with halothane. Anesth.Analg 1983;62:903-908.)

Nicardipina: aum dell’atonia uterina ,non facilmente
reversibile post partum con oxitocin:
– Csapo et al.Deactivation of the uterus during normal and premature labor by
the calcium antagonist nicardipine.Am,J.Obstet.Gynecol. 1982;142:483-91


Induzione AG
Tps < 7 mg/kg
metohexital 1 mg/kg
ketamina 1-1.5 mg/kg
etomidate 0.25-0.30 mg/kg
midazolam 0.2-0.3 mg/kg
propofol 2.5 mg/kg

non hanno significativi effetti sul
destino neonatale


Ipnoinduttori e C/S


Gin T,O'Meara ME,Kan AF,Leung RKW,Tan P,Yau G.PLASMA
CATECHOLAMINES AND NEONATAL CONDITION AFTER
INDUCTION OF ANAESTHESIA WITH PROPOFOL OR
THIOPENTONE AT CAESAREAN SECTION Br. J. Anaesth. 1993;

70:311-6

C/S elettivi,feto singolo
TPS 4 mg/kg vs propofol 2 mg/kg + succi/ iot dopo 1 min/ atrac/isof

MAP

TPS
+ 29 (SD 15) mm Hg

propofol
+ 18 (14) mm Hg)

Max noradr conc
Max adr conc

413 (177) pg ml-1
====

333 (108) pg ml-1
===

Apgar,NACS,catecol ombelicali,EGA,CO2 simili nei 2 gruppi

Propofol attenua la risposta ipertensiva e
catecolaminica all’iot;senza differenze di outcome

Gin T,Yau G,Jong W,Tan P,Leung RKW,Chan K.
DISPOSITION OF PROPOFOL AT CAESAREAN
SECTION AND IN THE POSTPARTUM PERIOD
CAN J ANAESTH 1991 / 38: 1 / 31-6
ABSTRACT: We have compared the pharmacokinetics of a
bolus dose of propofol 2 mg kg-1 in eight patients undergoing
Caesarean section with those in eight postpartum patients
undergoing sterilization by mini-laparotomy. The Caesarean
section group had a total body clearance of (median) 31.5 (range
24.4–53.3)ml min-1 kg-1, apparent volume of distribution at
steady state 5.10 (2.46–6.61) litre kg-1 and mean residence time
161 (52.3–251)min; values for the postpartum group were 33.8
(21.5–47.2) ml min-1 kg-1, 5.17 (3.47–8.09) litre kg-1 and 163
(92.3–238) min, respectively. The 95% confidence interval for
the umbilical venous to maternal venous ratio of propofol at
delivery was 0.62–0.86. Plasma protein binding studies showed
there was less unbound propofol in maternal plasma (1.28–
2.29%) compared with umbilical plasma (2.08–3.88%) (P <
0.01). Neonatal concentrations of propofol were greater than
maternal concentrations at 2 h and were in the range 0.05–0.11
mg ml-1 at 4 h


Gin T,Yau G,Chan K,Gregory MA,Oh TE.Disposition of
propofol infusions for Caesarean section.CAN J ANAESTH
1991 / 38: 1 / pp31-6

ABSTRACT: The disposition of propofol was studied in women undergoing elective
Caesarean section. Indices of maternal recovery and neonatal assessment were correlated
with venous concentrations of propofol. After induction of anaesthesia with propofol 2.0 mg ×
kg-1, ten patients received propofol 6 mg × kg-1 × hr-1 with nitrous oxide 50 per cent in
oxygen (low group) and nine were given propofol 9 mg × kg-1 × hr-1 with oxygen 100 per
cent (high group). Pharmacokinetic variables were similar between the groups. The mean ±
SD Vss = 2.38 ± 1.16 L × kg-1, Cl = 39.2 ± 9.75 ml × min-1 × kg-1 and t1/2b = 126 ± 68.7
min. At the time of delivery (8–16 min), the concentration of propofol ranged from 1.91–3.82
mg × ml-1 in the maternal vein (MV), 1.00–2.00 mg × ml-1 in the umbilical vein (UV) and
0.53–1.66 mg × ml-1 in the umbilical artery (UA).

Neonates with high UV
concentrations of propofol at delivery had lower
neurologic and adaptive capacity scores 15
minutes later. The concentrations of propofol were similar between groups during
the infusion but they declined at a faster rate in the low group postoperatively. Maternal
recovery times did not depend on the total dose of propofol but the concentration of propofol
at the time of eye opening was greater in the high group than the low group (1.74 ± 0.51 vs
1.24 ± 0.32 mg × ml-1, P < 0.01). The rapid placental transfer of propofol during Caesarean
section requires propofol infusions to be given cautiously, especially when induction to
delivery times are long.


Gin T,Yau G,Chan K,Gregory MA,Oh TE.Disposition of
propofol infusions for Caesarean section.CAN J ANAESTH
1991 / 38: 1 / pp31-6


The mean UV/MV ratio of 0.52 is lower than the 0.65–0.85 seen after bolus
induction doses of propofol and the 0.76 during an infusion study with I-D times of
7–31 min. Our I-D times (8–16 min) are shorter than the previous infusion study
and the lower UV/MV would indicate there is still a gradient for placental transfer
from the maternal to fetal circulations. The mean UA/UV ratio of 0.61 is similar to
the 0.70 with previous infusions and 0.67 after bolus induction with short I-D
times of 4–7 min. This indicates continuing fetal tissue uptake. However, bolus
induction studies with longer I-D times have UA/UV ratios of 1.09 and 1.07 which
imply more complete fetal distribution.
Neonatal depression in the low-infusion group was similar to that found after
an anaesthetic technique using thiopentone for induction of anaesthesia and
nitrous oxide and enflurane for maintenance of anaesthesia. The negative
correlation between NACS and UV concentrations of propofol provides some
evidence of neonatal depression due to propofol. Although infusion times were
too short to differentiate maternal concentrations of propofol between the two
groups, a high-dose infusion combined with a long induction to delivery time is
likely to produce high UV concentrations of propofol and low neonatal NACS
scores. The neonatal elimination of propofol is slower than the maternal
elimination (unpublished observations). Neonatal glucuronidation is poorly
developed but sulphation activity is similar to that found in adults.


Kee WD Ngan,Khaw KS, Ma ML., RN,Mainland P-A, Gin T.
Postoperative Analgesic Requirement After Cesarean Section:
A Comparison of Anesthetic Induction with Ketamine or
Thiopental. Anesth Analg 1997; 85:1294
ABSTRACT: In a randomized, double-blind study, we compared postoperative pain and analgesic
requirement in patients who underwent elective cesarean section under general anesthesia induced with
thiopental 4 mg/kg (n = 20) or ketamine 1 mg/kg (n = 20). Anesthesia was maintained with nitrous oxide
and isoflurane. Postoperative analgesia was provided by patient-controlled analgesia (PCA) using
morphine. Median (range) time to first PCA demand was greater in the ketamine group (28 [3–134] min)
compared with the thiopental group (20.5 [3–60] min; P = 0.04). Median (range) morphine consumption
over 24 h was less in the ketamine group (24.3 [3–41] mg) compared with the thiopental group (35 [4–67]
mg; P = 0.017). Visual analog scale pain scores were similar between groups. No patients had recall of
intraoperative events or unpleasant dreams. Two patients in the thiopental group and one patient in the
ketamine group had pleasant intraoperative dreams. Apgar scores were similar between groups. Median
umbilical venous pH was higher (7.33 vs 7.31; P = 0.04) and attributable to lower median umbilical
venous PCO2 (5.72 vs 6.14 kPa; P = 0.02) in the ketamine group compared with the thiopental group.
Induction of anesthesia for cesarean section using ketamine is associated with a lower postoperative
analgesic requirement compared with thiopental. Implications: Patients who had anesthesia for cesarean
section induced with ketamine required less analgesic drugs in the first 24 h compared with patients who
received thiopental. Ketamine, unlike thiopental, has analgesic properties that may reduce sensitization of
pain pathways and extend into the postoperative period.


Kee WD Ngan,Khaw KS, Ma ML., RN,Mainland P-A, Gin T.
Postoperative Analgesic Requirement After Cesarean Section:
A Comparison of Anesthetic Induction with Ketamine or
Thiopental. Anesth Analg 1997; 85:1294


Vantaggi della ketamina
Minor ipotensione
Possibilità di iniezione im
– Lum Hee WC,Metias VF.Intramuscular ketamine in a parturient in whom preoperative intravenous access was not possible . Br. J. Anaesth. 2001; 86

Maggiore profondità anestetica
» Gaitini L,Vaida S,Collins G,Somri M,Sabo E.Awareness detection
during Caesarean section under general anaesthesia using EEG
spectrum analysis .CAN J ANAESTH 1995 / 42: 5 / pp377-81

Minor necessità di analgesia postop


Protezione emodinamica dallo
stress dell’IOT
Oppioidi a breve azione:
» alfentanil 10 microgr/kg
Gin, T, Ngan-Kee, W D,Siu YK,Stuart JC,Tan P, Lam
KK.Alfentanil given immediately before induction of general
anesthesia for cesarean section.AA 2000;90:1467.
remifentanil 1-1.25 microgr/kg bolo lento o inf cont
– Ma PAS
– O'Hare R, McAtamney D,Mirakhur RK, Hughes D, Carabine U.Bolus dose of remifentanil
for control of haemodynamic response to tracheal intubation during rapid sequence
induction of anesthesia.BJA 1999;82:283.


Kan RE.Hughes S,Rosen MA,Kessin C,Preston PG,Lobo
EP.Intravenous Remifentanil: Placental Transfer, Maternal
and Neonatal Effects.Anesthesiology,98:1467-74, 1998


Schaut DJ Sevoflurane inhalation induction for emergency
caesarean section in a parturient with no intravenous
access.Anesthesiology 1997;86:1392.

Sevo 8%;incoscienza in 30”;5 min dopo
i.v. per paralisi e iot


Dopo il parto
Anestesia/analgesia indifferente?
A patto che non deprima la contrattilità
uterina……..


Risveglio
Estubare solo alla ripresa di una normale ventilazione e
normale funzione neuromuscolare!
Controllare forza !!
Se non avete ancora svuotato lo stomaco,fatelo prima del
risveglio!
» SNG/lavaggio/antiacido per contatto(citrato di sodio)

Profilassi del PONV?
» Valutazione dei fattori di rischio…
» Tenete conto dedlla profilassi ab
ingestis:ranitidina+metoclopramide

THE END


Chemioprofilassi dell’ab
ingestis


Inhalation anestesia for caesarean
section :why?
How?
C.Melloni
Servizio di Anestesia e Rianimazione
Ospedale di Faenza(RA)

Changes in obstetric anesthesia(C/S) in USA(Hawkins et
al,Obstetric anesthesia workforce survey-1992 versus
1981.Anesthesiology 1994;81:A1128)

100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%

Epid
Spi
GA

1981

1992


Changes in obstetric anesthesia(C/S) in UK(Brown et al.Int
J.Obstet.Anesth.1995;4:214)

100%
80%
Epid
Spi
GA

60%
40%
20%
0%

1982

1987

1992


Report on Confidential enquiries into maternal
deaths in England and Wales 1970-1996
Frequenza per milione di gravid.stimate
30

emb.polm
ipertens

25

anest

20
15
10
5
0

19 73- 76- 79- 82- 85- 88- 91- 9470- 75 78 81 84 87 90 93 96

emb.fluido amnio
aborto
gravid.ectopica
emorragia
sepsi
rottura utero
altre cause dirett

Entrata Faenza(RA)
Servizio di Anestesia e Rianimazione Ospedale di in vigore della nuova classificazione

Tsen LC, Camann W (2000) Training in obstetric general
anaesthesia: a vanishing art?Anaesthesia. 55:179-83


cardiovascular and metabolic effects of halothane in normoxic
and hypoxic newborn lambs. ANESTHESIOLOGY 62:732-7,
1985

Oxygen consumption, cardiac output,
and tissue oxygen delivery were
measured in normoxic and hypoxic 1-3day-old lambs during the following six
conditions: 1) (control) paralysis with
pancuronium and controlled ventilation
with room air; 2) paralysis, controlled
ventilation and hypoxia (PaO2 = 30 +/- 3
mmHg, [SD]); 3) paralysis, controlled
ventilation with room air and 0.5 MAC

Effects of halothane anesthesia 0.5 & 1
Mac in normoxic and hypoxic lambs

(Cameron

et al. The cardiovascular and metabolic effects of halothane in normoxic and hypoxic newborn lambs.

normoxia
1 mac

normoxia
0.5mac

hypoxia
1 mac

hypoxia
0.5mac

300
250
200
150
mean %
100
change
from control 50
0
-50
-100

hypoxia

ANESTHESIOLOGY 62:732-7, 1985)


O2 cons
CO
HR
MPAP
PVR
lactic acid
Norepi
Epi
SVR

Morti materne associate con l’anestesia in milioni di
gravidanze stimate per England & Wales
40
35
30
morti associate
direttamente
freq.per milione

25
20
15

% delle morti dirette

10
5
0

70- 73- 76- 79- 82- 85- 88- 91- 94- 9772 75 78 81 84 87 90 93 96 99


Maternal deaths UK 1994-96

thrombosis
PIH
early pregn
haemorrhage
AFE
Anaesthesia
others


Maternal deaths UK 1997-99

thrombosis
PIH
afe
haemorrhage
suicide
sepsis


New trends in UK maternal
mortality
Mort.rate among most disadvantaged
groups;20 *
Other than white :*2
Young<18
Increasing maternal age
Increasing parity
Obese
In vitro fertilization

Relative risk
C/S 4,9> vag(C/S is an amalgamation of
risk associated with the disorder for
which surgery is indicated and the risk
associated with the procedure itself….
Elective C/S 2.3
Emergent C/S 12.0
Instrum,vag delivery risk 3,1 vs vag deliv

Maternal deaths due to anesthesia:CEMD

20
18
16
14
12
10
8
6
4
2
0

85-87
88-90
91-93
94-96

direct

GA

indirect


Panchal et al.Maternal mortality during hospital
admission for delivery:a retrospective analysis using a
state maintained database.Anesth.Analg.2001;93:13441.
Jan 1984-dec 1997
Maryland
DRG C/S and vag.deliv,hospital
only,anonymous
Selected case controls
822.591 admissions for delivery
135 deaths
Maternal deaths/100.000 5.92-29,6

RISK factors(/100.000)(from Panchal et al)
Age;from 13,9<34 to 23,9>34
Caucasion 7,6,african.americans 31,6,18,1 others
African americans 5 times more prob to die during pregnancy
than caucasian
Social,cultural,economic,health care access,quality
factors;multiple diagnoses and severity of illness ++
C/S 5,3 +;60% of deaths associated with C/S
Minor teaching hospital 3,.1 +
Transfer from another hospital 6,2+

Maryland more common causes of
maternal mortality

precl/eclamp
postpartum hemorrh
pulm Ko
cvs event
AFE/clot
insuff prenatal care
trauma


MARYLAND STATISTICS on Maternal
deaths;african american vs caucasian
30
25
20
african-american
caucasian

15
10
5
0

precl/eclamp

pulm Ko

AFE/clot

AC.RENAL FAIL


Halper,SH et al.Effect of epidural vs parenteral opioid
analgesia on the progress of labor.JAMA
1998;280:2105-2110
Metanalysis
“epidural analgesia has a favourable
effect on funic pH and BE suggesting
that the known reduction in maternal
stress and sympathetic tone do improve
the intrauterine environment ,despite the
theorethical potential adverse effects…”

Decision-delivery interval
The 30 min.rule
Is this a standard that fetal distress
cases be delivered within 30 min?
Fetal hypoxia=scalp pH <7,2;serious
disability when pH<7.00
Correlation between DD interval and
neonatal asphyxia?

DD interval….
C/S ;DD interval shorter with GA(DD
23),but umb.cord artery pH better with
reg(DD 50).
Br Med J 322,June 2001
McKenzie1334-35


Reliability.CSE *C/S
1
0,9
0,8
0,7
QCH 1998
Norris 1994
Paech 1998
Albright 1999

0,6
% 0,5
0,4
0,3
0,2
0,1
0

failure rate


GA is not the choice for obs
emergencies
necessary only for true emergencies
Necessary only when:
» poor teamwork,
poor communication
,lack of reg skills

Necessary only for some fetal
conditions(tocolysis)
GA risk in pregnancy greater
GA not necessarily faster and faster my not
be better……….
– Crowhurst,2001

Section: A Comparison of Time
efficiency,Costs,Charges and Complications .Anesth
Analg 1995; 80:709–12
Retrospective study from their cases
C/S elective
epidural (n = 47) or spinal (n = 47) anesthesia
Patients who received epidural anesthesia had
significantly longer total operating room (OR) times than
those who received spinal anesthesia (101 ± 20 vs 83 ±
16 min, [mean ± SD] P < 0.001); this was caused by
longer times spent in the OR until surgical incision (46 ±
11 vs 29 ± 6 min, P < 0.001). Length of time spent in the
postanesthesia recovery unit was similar in both groups.
Supplemental intraoperative intravenous (IV) analgesics
and anxiolytics were required more often in the epidural
group (38%) e Rianimazione Ospedale di Faenza(RA)
Servizio di Anestesiathan in the spinal group (17%) (P < 0.05).

Spinal faster than epid….( Riley et al, Spinal

Versus Epidural Anesthesia for Cesarean Section: A Comparison of
Time Efficiency, Costs, Charges, and Complications.Anesth Analg
1995; 80:709–12)
120
100
80

min 60

epid
spi

40
20
0

OR-incis

total OR time

Pacu time


Drug(opioids,anxyolitics) consumption;spinal vs
peridural (Riley et al, Spinal Versus Epidural Anesthesia for Cesarean Section: A

Comparison of Time Efficiency, Costs, Charges, and Complications.Anesth Analg 1995;
80:709–12)

40

*

*

35
30
25
% 20
15

I catete intravasc
1 catet intratecale
1 perf dura
3 insuff analg

10
5
0

intraop
postop
KO

epid
spi

Direct costs($):Spi vs epid
45
40
35

kit
needle
drug
morph
fent
nurses 13 min
tot

30
25
20
15
10
5
0

spi

epid


Epid takes longer……..
Learning curve
the anesthesiologist must progress more slowly with the
epidural needle to avoid a dural puncture
the epidural catheter must be threaded and taped
a test dose must be given and the patient .observed for 3–5
min to exclude IV or intrathecal placement
the entire local anesthetic dose must be administered
incremental
onset of epidural anesthesia is slower than that of spinal
anesthesia.

Anesth prep time differed among groups( Glosten et

al.Practical aspects of regional anesthesia for cesarean delivery,failure rates and
anesthetic preparation times-An observational study..Anesthesiology 1995;83:A977. ):
70
60
50
40

GA
EPI
SPI

%

Min

30
20
10
0

failure rate

anest prep time

anest successful

anest unsuccess


Attitude in failed epidurals(Glosten et al.Practical aspects of regional
anesthesia for cesarean delivery,failure rates and anesthetic preparation times-An
observational study..Anesthesiology 1995;83:A977. ):

Repeat EPI 4
SPI 11
AG 9

epi d f a i l u r e s
( 2 4/ 1 79)
absent bl o ck 5 i n adeq blo ck 12 cat e t m is pla c 2( i v . ) par e st e si a 1

subdur a l 2

pat ie nt anxie t y 1


Attitude in failed spinalsGlosten et al.Practical aspects of regional
anesthesia for cesarean delivery,failure rates and anesthetic preparation times-An
observational study..Anesthesiology 1995;83:A977. ):

S p i fa ilu r e s
(3 /9 8 )
in a b ilit y t o o b t a in C S F

GA
in t r a o p p a in


USA changes in anesthesia for C/S( Hawkins et al,Obstetric
anesthesia workforce survey-1992 versus 1981.Anesthesiology 1994;81:A1128)

100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%

Epid
Spi
GA

1981

1992


UK changes in obs.anesthesia(Brown et al.Int
J.Obstet.Anesth.1995;4:214)

100%
80%
Epid
Spi
GA

60%
40%
20%
0%

1982

1987

1992


Ben David B,Miller G,Gavriel R,Gurevitch A.Low
dose bupivacaine-fentanyl spinal anesthesia for
cesarean delivery, Reg Anest PainMed.2000;25:235-39.
32 paz,20-40 anni
isobaric bupi 0.5% 10 mg vs 5 mg+fent 25
microgr
preload RL 500;intraop altri 800 ml
sitting,26 g pencil point;2 ml in 10-15 sec.
Poi supine + LLT
efedrina 5-10 mg as needed
tempo oper(dal’inizio della spi);<70 min
tutti,eccetto 1.

Ben David et al.Low dose bupivacaine-fentanyl
spinal anesthesia for cesarean delivery, Reg Anest
PainMed.2000;25:235-39.
100

0.001

90
80

0.05

70
min, 60
%, 50
mg 40
30
20

0.01

0.0002
0.0002

Liv medio T3
bupi 10 mg
bupi 5 + fent 25 mu

Liv medio T4-5

10
0

Meno blocco moto
time to peak
block

misur ipotens

nausea/vomito


Vercauteren MP,Coppejans HC,Hoffmann VH,Mertens E,Adriaensen
A.Prevention of hypotension by a single 5 mg dose of ephedrine during
small dose spinal anesthesia in prehydrated cesarean delivery
patients.AA 2000;90:324-327.

Cimetidine p.o 900 mg 1 h prima della
induzione
RL 1000 ml iniziato 10’ prima del
trasferimento in S.OP
HES 6% 500 ml all’arrivo in sala op
Induzione di CSE
dec,.lat dx
bupi 6,6 mg+sufent 3.3 microgr intratecale
inserito catet pd
doppio cieco efedr 5 mg vs placebo

Steer, Phyllis L., MD*; Biddle, Chuck J., PhD*; Marley, Wanda S., CRNA MS*†; Lantz, Robert K., PhD‡;
Sulik, Patricia L., PhD‡
From the Departments of Anesthesiology at University of Kansas,* Kansas City, Kansas, and Poudre Valley
Hospital,† Ft. Collins, Colorado, Rocky Mountain Instrumental Laboratories, Inc.,‡ Fort Collins, Colorado.
Research conducted at the Poudre Valley Hospital, Ft. Collins, Colorado.
Address correspondence to: Dr. Phyllis L. Steer, University of Kansas Medical Center, 39th and Rainbow,
Kansas City, Kansas 66103.
Funded by the School of Allied Health, University of Kansas and Janssen Pharmaceutica.
Accepted for publication 25th November, 1991.
ABSTRACT: The purpose of this study was to measure the concentration of fentanyl in human colostrum
after intravenous administration of an analgesic dose. Thirteen healthy women were given fentanyl 2 mg
kg-1 for analgesic supplementation during either Caesarean section or postpartum tubal ligation. Serum and
colostrum were collected for 45 min, two, four, six, eight, and ten hours following administration of the drug.
Radioimmunoassay showed that colostrum fentanyl concentrations were greatest at 45 min, the initial
sampling time, reaching 0.40 ± 0.059 ng ml-1, but were virtually undetectable ten hours later. Fentanyl
concentrations were always higher in colostrum than in serum. This concluded that with these small
concentrations and fentanyl's low oral bioavailability, intravenous fentanyl analgesia may be used safely in
breast-feeding women.


Vercauteren et al Prevention of hypotension by a single 5 mg dose of
ephedrine during small dose spinal anesthesia in prehydrated cesarean
delivery patients.AA 2000;90:324-327.Results
80
70

Livello T3
1 per ogni gruppo lidoc 2%
p.d.

60
50

efedr 5 mg
placebo

40
30
20
10
0

altra efedr

ipotens<90

vomito


Coagulation and anesthesia
The Effect of Anesthetic Techniques on Blood
Coagulability in Parturients as Measured by
Thromboelastography
Sharma, Shiv K., MD, FRCA; Philip, John, MD
: Anesthetic techniques may affect blood coagulability and the
subsequent incidence of thromboembolic events. The purpose of this
study was to evaluate the effect of spinal and general anesthesia on
blood coagulability in normal pregnant women undergoing cesarean
section, using thromboelastography. In the spinal anesthesia group (n =
15), thromboelastography was performed after crystalloid preloading
and during the immediate postanesthesia course. In the general
anesthesia group (n = 15), thromboelastography was performed before

Minimizzazione dell’anestesia
materna(‘40-’60)

“awareness”


Senza danno per il neonato:
Moir,DD.Anesthesia for caesarean
section:an evaluation of a method using
low concentration of halothane and
50% oxygen.Br.J.Anaesth.1970;43:13642.

Halothane 0.5%


“Fetal distress”
The term fetal distress is imprecise,non specific and
has little positive predictive value(ACOG Committee
Opinion: Anesthesia for emergency deliveries. Number 104. March
1992)

definizione:
» progressive fetal asphyxia that, if not corrected or circumvented
will result in decompensation of the physiologic responses
(primarily redistribution ofblood flow to preserve oxygenation of
vital organs) and cause permanent and central nervous system
damage and other damage or death.”(Parer JT, Livingston EG: What is
fetal distress? Am J Obstet Gynecol 162:1421, 1990)


parto cesareo di urgenzaemergenza
– In the obstetric and anesthetic management
of emergent abdominal deliveries, "the
maternal as well as fetal status must be
considered .. The risk of general anesthesia
must be weighed against the benerit for
those patients who have a greater potential
for complications... Cesarean deliveries
which are performed for non‑ reassuring FHR
patterns do not necessarily preclude the use
of regional anesthesia.”(ACOG Committee Opinion:
Anesthesia for emergency deliveries. Number 104. March 1992)

Domande:
Potete ottenere una spinale nel + breve
tempo possibile?


Siete sempre in grado di
garantire una spinale rapida?
S p in a le r a p id a
Si
B u p i s e m p lic e
ok

NO
AG

non ok

p r o b le m i d i io t


AG per il distress fetale
Ket> TPS nel modello sperimentale
Levinson G, Shnider SM, Gildea E, deLorimier M: Maternal and
foetal cardiovascular changes and during ketamine
anesthesia in pregnant ewes. Br J Anaesth
45:1111,1973:Pickering BG, Palahniuk RJ, Cote J, et al:
Cerebral vascular responses to ketamine and thiopentone during
foetal acidosis. Can.Anaesth Soc J 29:463, 1982

ma…..evidenza clinica=,senza contare le CI alla
ket(preeclampsia,cocaine abuse….)


Deterioramento fetale

(Goodman J, Godewen J, Chance G eds. Fetal acid‑base physiology and fetal asphyxia.
In Perinatal Medicine, Baltimore,Williams and Wilkins, 1977, p. 201)

Cessazione di GC fetale adeguata (p.es FHR<
90,prolasso del cordone)
ogni min
pH 0.03-0.04 u.
pCO2 3-4 mmHg
BE interst
0.80.


Il significato di emergenza
Diverso fra:
anestesista
ostetrico
nurse
paziente
pediatra
avvocato……o magistrato………….

Sequenza temporale
i 2-5 min spesi dall’anestesista non
corrisponderebbero forse…
alla modificazione della situazione ostetrica
determinata da una più precoce decisione di
operare….
Al miglioramento della condizione materno-fetale:
» dec lat
» ossigenazione
» espansione volemia
» tocolisi Anestesia e Rianimazione Ospedale di Faenza(RA)
Servizio di

Conclusioni dai dati di
mortalità-morbilità
Non sarà che la mortalità -morbilità
materna(e fetale) è più legata
all’emergenza-urgenza che all’elezione?


Indicazioni per C/S urgente
Materne:
» peggioramento acuto
di malattia
preesistente
» emorragia massiva
» trauma
» arresto cardiaco(TC
perimortem)

Fetali:
» parte fetale prolassata:
– cordone,
– estremità(fallita estraz podalica,fallita estraz di
testa con distocia di spalla…)

» compromissione della
circolazione centrale:
– deceleraz tardive non riflesse,senza
variabilità,
– bradicardia prolungata
– acidemia fetale..

» Danno fetale
– da trauma uterino,chiuso o penetrante
– emorragia indotta dalla cordocentesi


1992 ACOG Committee Opinion on Anesthesia
for emergency deliveries

The entire obstetric care team should be
alert to the parturient at increased risk
from complications from emergency
general or regional anesthesia. When
risk factors are identified, an
anesthesiologist should be consulted in
the antepartum period to allow for joint
development of a plan of

management.


pressure during spinal
anaesthesia for Caesarean section.
Br J Anaesth 2004; 92:469-74.
Editorial
AUTHOR(S): Riley, E. T.
My prediction is that within the next few years we will be treating hypotension after spinal anaesthesia in a fundamentally different way than we have during the
last 20 years. We will no longer use ephedrine as the mainstay of treatment, we will be more aggressive about maintaining arterial pressure near normal, and we
will worry less (if at all) about the liberal use of other vasoconstricting drugs. In another important contribution by this group, Ngan Kee and colleagues provide
evidence that will help us determine the optimal way for preventing the detrimental effects of maternal hypotension after induction of spinal anaesthesia for
Caesarean delivery. In this study, the authors maintained maternal arterial pressure at 80%, 90% or 100% of baseline. Using umbilical artery pH as their primary
outcome, they found that maintaining the arterial pressure at 100% of baseline was associated with the best outcome for the baby (highest umbilical artery pH)
and the mother (less nausea).
Although it is not surprising that maintaining homeostasis is the best strategy, this study shatters the long-held notion that it is best to minimize the use of
vasopressors in pregnant patients. It has long been held that vasoconstriction from predominantly alpha-adrenergic agonist drugs will decrease uterine blood flow
(UBF) and be harmful to the fetus. Maintenance of low placental vascular resistance and thus better UBF was considered more important than any adverse
effects resulting from a 20–30% decrease in maternal arterial pressure.
How did the notion develop that it is better to let the arterial pressure drift down rather than risk placental vasoconstriction? Several sheep studies showed that
large doses of vasoconstricting drugs decreased UBF. However, ephedrine maintained UBF much better than other pressors that are primarily vasoconstrictors
and have little beta-agonist effect (e.g. phenylephrine and metaraminol). Therefore, ephedrine became the 'gold standard' for prophylaxis and treatment of spinal
hypotension.
Accumulating evidence that doses of ephedrine large enough to maintain homeostasis after the induction of spinal anaesthesia may be detrimental to the fetus
are causing a major change in our approach to this problem. In a recent study, Cooper and colleagues compared ephedrine and phenylephrine for the treatment
of maternal hypotension. Consistent with other recent studies, they found ephedrine caused more acidosis in the fetus. A unique aspect of Cooper and
colleagues' study is their evaluation of the degree of acidosis seen in the umbilical vessels. They calculated the difference between the PCO2 in the umbilical
artery and umbilical vein (PCO2 (art-vein)). If the PCO2 (art-vein) is small, this indicates poor placental perfusion or gas exchange. For example, conditions such
as placental abruption have a small PCO2 (art-vein). If the PCO2 (art-vein) is large, this suggests that acidosis in the umbilical artery is secondary to a process in
the fetus. Cooper and colleagues found a strong correlation between ephedrine use and an increase in the PCO2 (art-vein). From these data they concluded that
ephedrine was stressing the fetus and may have contributed to fetal acidosis.
There is additional evidence that ephedrine may adversely affect the fetus. When ephedrine was given to women in labour, there were changes in the fetal
heart rate pattern (tachycardia and abnormal increases in variability) that might indicate fetal stress or an increase in fetal metabolic activity. These changes were
dose related.
Other commonly used vasopressors do not have as much beta-agonist activity and thus do not increase metabolism in the fetus. For example, Cooper and
colleagues found no correlation between phenylephrine dose and an increase in the PCO2 (art-vein). The current study, as well as others by Cooper and
colleagues and Mercier and colleagues, all reported use of large doses of phenylephrine given to maintain a baseline arterial pressure without any adverse effect
on the fetus.
Why do these large doses of phenylephrine (sometimes over 1000 mg total dose) not cause clinically significant vasoconstriction and decreased placental
perfusion? Although these large doses were needed to maintain homeostasis, they did not increase arterial pressure to supranormal levels. Therefore, these
doses should be considered appropriate for correcting the vasodilatation secondary to a spinal anaesthetic.
The parturient's decreased sensitivity to sympathomimetics during pregnancy may help protect the fetus from excessive vasoconstriction. Tong and Eisenach
demonstrated that uterine arteries from pregnant ewes were less responsive to vasoconstrictors compared with those from non-pregnant ewes. Giving large
doses of alpha-agonists that constrict peripheral arteries and restore normal maternal arterial pressure may preferentially shunt blood to the uterine arteries, which
may be relatively spared from the vasoconstrictive effect.
We must also consider the possibility that significant placental vasoconstriction does occur with phenylephrine, but may not be important with regard to fetal
wellbeing. Of particular interest in Ngan Kee and colleagues' article in the current issue is the trend for an increase in umbilical artery PO2 to occur in conjunction
with higher maternal arterial pressures (although this did not quite reach statistical significance - P=0.058). This finding is consistent with my observations during
ex utero intrapartum therapy procedures and fetal surgery. In these cases, the fetus is at least partially extracted from the uterus but not separated from the
placenta. The fetus continues to be supported by the placenta while a procedure is performed. In all instances, a pulse oximeter probe was placed on the fetus. In


Database dei “Closed claims”(richieste di
risarcimento) per l’ awareness intraop

79 / 4183 claims;1.9% :
» 18 richieste per awake paralysis(paralisi da svegli)
paralisi involontaria di un paz cosciente
» 61 richieste per ricordi durante GA :ricordo di eventi in
corso di GA


Awareness claims
1.9% of all claims
awareness, defined as being paralyzed while
awake or awake while receiving a general
anesthetic, were reviewed. These claims were

further divided into two categories: awake
paralysis, i.e., the inadvertent paralysis of an
awake patient, and recall during general
anesthesia, i.e., patient recalled events while
receiving general anesthesia.

Closed claim database for
intraoperative awareness
The majority of awareness claims involved :
»
»
»
»

women (77%)(OR 3.21)
younger than 60 yr of age (89%)
ASA I—II (68%)
who underwent elective surgery (87%),obs/gynecol.

Claims for recall during general anesthesia were more likely to
involve :
» women (odds ratio [OR] = 3.08, 95% confidence interval [CI] = 1.58, 6.06)

anesthetic techniques using intraoperative opioids (OR = 2.12, 95%
CI = 1.20, 3.74)
intraoperative muscle relaxants (OR = 2.28, 95% CI = 1.22, 4.25)
and no volatile anesthetic (OR = 3.20, 95% CI = 1.88, 5.46).

Ranta S, Laurila R,Saario J,Ali-Melkkilä T, Hynynen M.
Awareness with Recall During General Anesthesia: Incidence
and Risk Factors Anesth Analg 1998; 86:1084
4818 operations under GA: 2612 (54%) patients were
interviewed
10 (0.4% of those interviewed) patients were found to have
undisputed awareness
9 (0.3%) patients with possible awareness.
The doses of isoflurane (P < 0.01) and propofol (P < 0.05)
were smaller in patients with awareness.
5 patients with awareness underwent a psychiatric
evaluation;possible association with depression.
1 patient experienced sleep disturbances afterward, but the
other four patients did not have any after effects.

Approfondimenti sugli effetti degli
anest.volatili sul feto ( e neonato
subito dopo la nascita)


Dwyer, R.; Fee, J. P. H.; Moore, J.
Uptake of halothane and isoflurane by mother and baby
during cesarean section.BJA 1995;74:279
: Twenty–three patients undergoing Caesarean section received either 0.5% halothane or 0.8%
isoflurane to supplement nitrous oxide–oxygen anaesthesia. We studied the rate of uptake of
the agents by the mother and fetus by measuring partial pressures in maternal arterial (Pa)
and fetal umbilical venous (Puv) blood. Mean induction– delivery interval did not differ between
the halothane (10.8 min) and isoflurane (11.7 min) groups. There were no differences in
maternal heart rate, arterial pressure, pH and blood–gas tensions and fetal pH, blood–gas
tensions or Apgar scores between the two groups. Isoflurane uptake by the mother was more
rapid than halothane; at delivery, mean Pa of isoflurane as a fraction of the inspired partial
pressure (PI) was 0.44 compared with 0.35 for halothane (P < 0.05). Mean Puv as a fraction of
maternal Pa at delivery was 0.71 for both agents; thus placental transfer was the same for
both agents. Consequently mean Puv/PI was greater for isoflurane (0.32) than halothane
(0.26) (P < 0.05). We conclude that both halothane and isoflurane are suitable agents for
general anaesthesia for Caesarean section. The rate of uptake of isoflurane by

the mother during Caesarean section was more rapid than halothane.
The rate of uptake by the fetus from the mother was the same for
halothane and isoflurane, so that fetal partial pressure as a fraction of
the inspired partial pressure was greater for isoflurane than halothane.

rate of uptake of halothane and isoflurane by the mother and
fetus by measuring partial pressures in maternal arterial (Pa)
and fetal umbilical venous (Puv) blood


Wojtczak, Jacek A. The Hemodynamic Effects of Halothane
and Isoflurane in Chick Embryo Anesth Analg 2000; 90:1331
The cardiovascular effects of volatile anesthetics in prenatal hearts are not well
investigated. The purpose of this study was to determine whether the embryonic
cardiovascular system is sensitive to an exposure to clinically relevant, equipotent
concentrations of halothane and isoflurane. Stage 24 (4-day-old) chick embryos were
exposed to 0.09 and 0.16 mM of halothane and 0.17 and 0.29 mM of isoflurane.
Dorsal aortic blood velocity was measured with a pulsed-Doppler velocity meter .

Halothane, but not isoflurane, caused a significant
decrease in cardiac stroke volume and maximum
acceleration of blood (dV/dtmax), an index of cardiac
performance. This effect was reversible, and during washout, stroke volume
and dV/dtmax increased above control levels. Embryonic heart rate was not affected
by either drug. Chick and human embryos are similar during early stages of
development; therefore, chick embryo may be a useful model to study the
cardiovascular effects of anesthetics.


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