Anesthesia for Cesarean Section

1. Anesthesia for Cesarean Section -Emergent C/S & General Anesthesia Department of Anesthesiology,NTUH R3 Chang-Fu Su

2. 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.

3. Indication for Cesarean Section-1 • Repeat cesarean section • Scheduled • Failed attempt at vaginal delivery • Dystocia • Abnormal presentation • Transverse lie • Breech presentation • Multiple gestation

4. Indication for Cesarean Section-2 • Fetal stress/distress • Deteriorating maternal medical illness • Preeclampsia • Heart disease • Pulmonary disease • Hemorrhage • Placenta previa • Placenta abruption

5. 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

6. Anesthetic technique • Spinal anesthesia • For most elective and urgent C/S • Epidural anesthesia • Decrease likelihood of hypotension • Combined Spinal-Epidural anesthesia • General anesthesia

7. 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

8. 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

9. 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

10. 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

11. Emergency Cesarean Section(1)- Stable • Chronic uteroplacental insufficiency • Abnormal fetal presentation with ruptured membrane (not in labor) • ==>Preferred anesthetic technique : Epidural, spinal

12. Emergency Cesarean Section(2)-Urgent • Dystocia • Failed trial of forceps • Active genital herpes infection with ROM • Previous classical C/S and activelabor • Cord prolapse without fetal distress • Variable deceleration with prompt recovery and normal FHR variability • Extension of preexisting epidural anesthesia or Spinal

13. 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

14. 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)

15. 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?

16. Thanks for your attention!