Anesthesia for Cesarean Section

-Emergent C/S & General Anesthesia

Department of Anesthesiology,NTUH

R3 Chang-Fu Su

Cesarean Section

• C/S rate 14-15% at US (20-25% at Taiwan)

• Anesthesia: 3-12% maternal death– Majority during G/A: failed intubation,

ventilation, oxygenation and pulmonary aspiration of gastric content

– Risk factor: obesity, hypertensive disorder of pregnancy, emergently performed procedure.

Indication for Cesarean Section-1

• Repeat cesarean section– Scheduled– Failed attempt at vaginal delivery

• Dystocia

• Abnormal presentation– Transverse lie– Breech presentation– Multiple gestation

Indication for Cesarean Section-2

• Fetal stress/distress

• Deteriorating maternal medical illness– Preeclampsia– Heart disease– Pulmonary disease

• Hemorrhage– Placenta previa– Placenta abruption

Preparation of Anesthesia

• Preanesthetic medication– Sedative drug(x), atropine (x,not routine)

• Intravenous fluids– 15-20 ml/kg L/R or N/S within 30 min– In urgent situation, not necessary to wait– Keep BP ,improve uteroplacental perfusion

• Maternal position (avoid aortocaval compression , left uterine displacement)

• Monitoring

Anesthetic technique

• Spinal anesthesia– For most elective and urgent C/S

• Epidural anesthesia– Decrease likelihood of hypotension

• Combined Spinal-Epidural anesthesia

• General anesthesia

Epidural anesthesia

• Advantage– Titration (volume dependent, not gravity dependent),

decreased likelihood of hypotension– Incremental dose (for longer operation)

• Disadvantage– Dural puncture :1/200-1/500 in experienced hands,

higher in training institution– If unintentional dural puncture, PDPH incidence is 50-

85%– Slower onset

General anesthesia

• Regional anesthesia is best in most C/S

• Avoid GA in difficult intubation, hx of malignant hyperthermia, severe asthma

• Risk of maternal aspiration and neonatal depression

General anesthesia for C/SMethod (1)

• Left uterine displacement, monitor, pre-oxygenation ,wait for operator preparation

• Cricoid pressure (rapid sequence induction)• Induction: ketamine(1.0mg/kg) or thiopental

(4mg/kg) and SCC(1.0-1.5 mg/kg) or (rocuronium)

• Intubation with a smaller ET tube

• 30%-50% N2O in O2 and low concentration volatile inhalation anesthetic

General anesthesia for C/SMethod (2) After delivery

• Increase N2O with or without low concentration volatile inhalation anesthetic

• Opioid• Intravenous hypnotic agent (benzodiazepine,

barbiturate, propofol) if needed• Muscle relaxant• Extubation awake with intact airway reflex

Emergency Cesarean Section(1)- Stable

• Chronic uteroplacental insufficiency

• Abnormal fetal presentation with ruptured membrane (not in labor)

• ==>Preferred anesthetic technique : Epidural, spinal

Emergency Cesarean Section(2)-Urgent

• Dystocia• Failed trial of forceps• Active genital herpes infection with ROM• Previous classical C/S and active labor• Cord prolapse without fetal distress• Variable deceleration with prompt recovery and

normal FHR variability• Extension of preexisting epidural anesthesia or

Spinal

Emergency cesarean section(3)-Stat

• Massive maternal hemorrhage• Ruptured uterus• Cord prolapse with fetal bradycardia• Agonal fetal distress (e.q., prolonged

bradycardia or late deceleration with no FHR variability)

• General unless preexisting epidural anesthesia can be extend satisfactorily

Other indication for GA for C/S?

• Severe pre-eclampsia (hypertension, proteinuria)– HELLP (Hemolysis, Elevated Liver Enzyme, and

Low Platelets)

• Eclampsia

• Contraindication for regional anesthesia ( patient deny, local infection, bleeding tendency, local infection over injection area, allergy to local anesthetic)

Discussion

• Does low concentration volatile halogenated agent or non-depolarizing muscle relaxant depress uterine contraction?

• Does Opioid accumulate in breast milk? (45min, 10hr)

• Is our GA patient under enough anesthesia?

Thanks for your attention!