Anesthesia for Cesarean Section

Lars Irestedt

Karolinska University Hospital,

Stockholm, Sweden

1. Indication and emergency

2. Airway problems expected?

3. GA really necessary?

Three important questions

Indication for GA at CS

• CNB contraindicated• Patient refuses CNB• Immediate CS• CNB failure

Disadvantages with GA for CS

Higher mortalityAirway problems?Aspiration?Awareness - recall?Hemodynamics?Atonia of the uterus?Neonatal effects?

1964-66 2000-02

CS % 3.4 21

CNB% ~0 ~80

Anesthesia relatedmortality per million anesthetics

360 10

Why mothers die

www.cemach.org.uk

Anesthesia related maternal mortality per million anesthetics

2000-2002

GA 50

CNB 3

Why mothers die

www.cemach.org.uk

Anesthesia related maternal mortality per million anesthetics 2000-2002

General anesthesia 50

Regional anesthesia 3

Why mothers die

www.cemach.org.uk

Selection bias!

Failed intubation

Obstetric population 1/280

General population 1/2200

Anaesthesia 1987:42:487-490

23 failed tracheal intubations occurred in 5802 obstetric general anesthetics between 1981 and 1994 corresponding to 1/252

BJA 1996:76:680-684

20 failed tracheal intubations occurred in 4768 obstetric general anesthetics between 1999 and 2003 corresponding to 1/238

Anaesthesia 2005:60:168-171

4 failed tracheal intubations occurred in 1095 obstetric general anesthetics between 2005 and 2006 corresponding to 1/273

Int J Obst Anesth 2008:17:292-297

Why is airway handling more difficult in the obstetric patient?

• Anatomical changes

• Physiological changes

• Increased risk for aspiration

• Often an emergency situation

PaO2 after 60 sec of apnea

Br J Anaesth 1974:46:358-360

PaO2 before apnea (kPa)

PaO2 after apnea (kPa)

(%)

Pregnant 63.1 44.5 30

Non pregnant

67.6 59.9 11

CNB and CS

• Spinal anesthesia

• Epidural anesthesia

• Combined spinal epidural anesthesia (CSE)

Optimal technique

• Subarachnoidal injection L3-L4• Check BP and HR every minute until delivery• Position, left lateral tilt• Vasopressor readily avalible• Rapid isotonic saline infusion• Careful preop testing of blockade height• Optimal height of blockade – above T5• Slow inj. of oxytocin 5 IU after cord clamping

Contraindication, SPA

• Uncompensated hypovolemia• Severe Coagulopathies• Local infection• Patient refuses• Septicemia

CNB and CS

• Spinal anesthesia• Epidural anesthesia (if already on board)

Majority of cases

GA and CS

• Always RSI

• Preoxygenation

• Emergency contra elective

• Cricoid pressure?

• What is good for the mother is good for the baby

Bild Stockholm