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 % –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/S Method (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 ( mg/kg) or (rocuronium) Intubation with a smaller ET tube 30%-50% N 2 O in O 2 and low concentration volatile inhalation anesthetic

General anesthesia for C/S Method (2) After delivery Increase N 2 O 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!