Chapter 48: General Anesthesia for Cesarean Delivery

BACKGROUND

• General anesthesia (GA) has largely been replaced by neuraxial due to decreased maternal mortality and morbidity and improved fetal outcomes (Chapter 47, “Neuraxial Anesthesia for Cesarean Delivery”).

• Indications:

  • Maternal refusal of neuraxial anesthesia.

  • Severe psychiatric or developmental disorder.

  • Coagulopathy.

  • Local infection at the neuraxial site.

  • Severe, uncorrected hypovolemia.

  • Intracranial mass with increased intracranial pressure.

  • Failure of the neuraxial block to rise in urgent or emergent cesarean.

  • Umbilical cord prolapse with persistent fetal bradycardia.

  • Incomplete coverage of spinal anesthesia.

  • Multiple failed neuraxial placements.

  • Persistent intraoperative pain that is uncontrolled.

• STAT or urgent intrapartum indications for GA should involve constant communication between the obstetrician and anesthesiologist. This ensures a continued need for GA and updates everyone on the current steps in the ongoing process.

PREOPERATIVE

• Perform standard evaluation, consent, and multidisciplinary huddle.

• Place a 16 or 18 G peripheral intravenous catheter and obtain a complete blood count and type and screen blood bank sample.

• Administer nonparticulate antacid <30 minutes before induction.

• May consider metoclopramide 10 mg and/or ranitidine 30 mg IV if >30 minutes prior to induction.

• In patients with high body mass index may consider the placement of a ramp to optimize patient positioning for intubation.

• If the patient is greater than 20 weeks of gestation (uterus at or above the umbilicus), it is vital to place the patient in left uterine displacement prior to induction.

• Administer indicated antibiotics.

• Perform preoxygenation with either 100% O₂ for 3 minutes or 4 to 8 vital capacity breaths.¹

• Ensure the patient is prepped and draped, perform time-out, and confirm surgeon is ready for incision. This is done to shorten the time from induction to delivery, which minimizes the anesthetic effect on the neonate.

INDUCTION

• Initiate rapid sequence induction.

• Propofol 2.0 to 2.5 mg/kg of ideal body weight (IBW) and succinylcholine 1.0 to 1.5 mg/kg of total body weight. Etomidate 0.3 mg/kg may be used with hypovolemia.

  • Avoid opioids and benzodiazepines before delivery, as they cross the placenta and may cause neonatal respiratory depression.

• Wait ∼30 to 45 seconds, then perform tracheal intubation.

  • Ideally, a senior anesthesiologist or an attending should be the intubator.

  • Airway edema associated with pregnancy, labor and preeclampsia may necessitate video laryngoscopy; this should be ready if not the first choice.

  • Endotracheal tube size 6.5 or 6.0 mm should be considered in light of airway edema.²

• Confirm placement and inform obstetricians that it is safe to initiate surgery.

INTRAOPERATIVE PRIOR TO DELIVERY

• Use volatile anesthetic (sevoflurane, isoflurane, or desflurane) at approximately 1 minimum alveolar concentration (MAC).

• Recommended initial ventilator settings of 6 to 8 mL/kg of IBW and a respiratory rate of 14 to 18/min.

• There is a compensatory respiratory alkalosis in pregnancy with a normal PaCO₂ of 30 mm Hg. Ventilator settings should be titrated to maintain patients near this baseline.

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