Anesthesia for Cesarean Section - Emergent C/S and General Anesthesia

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

– Scheduled

– Failed attempt at vaginal delivery

• Dystocia

• Abnormal presentation

– Transverse lie

– Breech presentation – Multiple gestation

Indication for Cesarean Section-2

• 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)

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

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(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/S

Method (2)

• Increase N₂O with or without low

concentration volatile inhalation anesthetic • Opioid

• Intravenous hypnotic agent (benzodiazepine, barbiturate, propofol) if needed

• Muscle relaxant

Emergency Cesarean Section(1)-

Stable

• Chronic uteroplacental insufficiency

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

• ==>Preferred anesthetic technique :

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

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

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)

Thanks for your

attention!