NBCRNA Obstetric Anesthesia 1 — Questions and Answers
Question 1: What is the preferred anesthetic technique for cesarean delivery in most elective cases?
- General anesthesia with rapid sequence induction
- Spinal anesthesia (Correct answer)
- Epidural anesthesia
- Combined spinal-epidural anesthesia
Correct answer: Spinal anesthesia
Spinal anesthesia is preferred for elective cesarean delivery because it provides rapid onset, dense block, avoids airway instrumentation, and allows the mother to remain awake.
Question 2: At approximately what gestational age is an obstetric patient considered to have a full stomach and at increased aspiration risk during anesthesia?
- 8 weeks
- 14 weeks (Correct answer)
- 18 weeks
- 24 weeks
Correct answer: 14 weeks
From approximately 14 weeks gestation, progesterone-induced lower esophageal sphincter relaxation and uterine compression of the stomach increase aspiration risk.
Question 3: Which vasopressor is currently recommended as the first-line treatment for spinal hypotension during cesarean delivery?
- Ephedrine
- Epinephrine
- Phenylephrine (Correct answer)
- Dopamine
Correct answer: Phenylephrine
Phenylephrine is the first-line vasopressor for spinal hypotension in obstetrics because it maintains uteroplacental blood flow better than ephedrine and is associated with less fetal acidosis.
Question 4: What dermatome level of sensory blockade is required for adequate spinal anesthesia during cesarean delivery?
- T6
- T4 (Correct answer)
- T2
- T10
Correct answer: T4
A sensory block to T4 (nipple line) is required for cesarean delivery to cover peritoneal manipulation and uterine exteriorization.
Question 5: Which local anesthetic is most commonly used for spinal anesthesia in obstetric patients undergoing cesarean delivery?
- Lidocaine 5%
- Bupivacaine 0.75% hyperbaric (Correct answer)
- Ropivacaine 0.5%
- Chloroprocaine 3%
Correct answer: Bupivacaine 0.75% hyperbaric
Hyperbaric bupivacaine 0.75% is the most widely used spinal local anesthetic for cesarean delivery due to its reliable dense block, predictable spread, and long duration.
Question 6: What physiological change in pregnancy most significantly decreases the MAC requirement for volatile anesthetic agents?
- Increased cardiac output
- Elevated progesterone levels (Correct answer)
- Respiratory alkalosis
- Increased blood volume
Correct answer: Elevated progesterone levels
Elevated progesterone levels during pregnancy decrease MAC requirements for volatile anesthetics by approximately 25-40% through CNS depressant effects.
Question 7: What is the most common cause of maternal mortality directly related to obstetric anesthesia in developed countries?
- High spinal block
- Local anesthetic systemic toxicity
- Failed or difficult airway management (Correct answer)
- Aspiration pneumonitis
Correct answer: Failed or difficult airway management
Failed or difficult airway management during general anesthesia remains the leading direct anesthesia-related cause of maternal mortality due to airway changes in pregnancy.
NBCRNA Obstetric Anesthesia 1
What is the preferred anesthetic technique for cesarean delivery in most elective cases?