Obstetric Anesthesia
Thoha Pham
1. Beyond midgestation, pregnant women are at increased risk of gastroesophageal reflux and aspiration of gastric contents for all these reasons, except
A. Decreased competence of the lower esophageal sphincter
B. Delayed gastric emptying associated with the onset of labor
C. Delayed gastric emptying due to opioid administration
D. Increased incidence of constipation
2. Changes in the cardiovascular system associated with pregnancy include
A. Increase in central venous pressure
B. Increase in cardiac output
C. Increase in systemic vascular resistance
D. Increase in blood pressure
3. During pregnancy, the disproportionate increase in plasma volume versus erythrocyte volume accounts for
A. Increase in the mean arterial pressure
B. Increase in stroke volume
C. Increase in cardiac output
D. Relative anemia of pregnancy
4. By the third trimester of pregnancy, cardiac output increases to nearly 50% due to which of these alterations?
A. Increase in stroke volume and increase in heart rate
B. Decrease in stroke volume and increase in heart rate
C. Increase in stroke volume and decrease in heart rate
D. Decrease in stroke volume and decrease in heart rate
5. The largest increase in cardiac output is seen during this peripartum period:
A. During induction of anesthesia
B. During the start of labor
C. Immediately after delivery
D. At conception
6. A 20-year-old G1P0 female at 425 weeks of gestation presents to labor and delivery floor with rupture of membranes and onset of early labor. She appears uncomfortable and becomes extremely anxious with peripheral IV placement, and begins to hyperventilate. If allowed to continue hyperventilation, it will cause
A. Increased placental perfusion
B. Decreased maternal arterial pH
C. Increased fetal arterial pH
D. Decreased maternal uterine artery flow
7. In the above patient, labor is nonprogressive with signs of fetal distress on heart rate monitoring. Spinal anesthesia with 2-chloroprocaine 3% (2 mL) is provided for emergent cesarean section. On postpartum day 2, she complains of leg numbness, which quickly progressed to flaccid paralysis. On examination, inability to move her lower extremities with complete loss of pain and temperature sensation below T4 with normal sensation to light touch was noted. The most likely cause of this complication is
A. 2-Chloroprocaine neurotoxicity
B. Inadvertent subdural injection
C. Anterior spinal artery syndrome
D. Brown-Séquard syndrome
Questions 8 to 9
A 23-year-old female, in early labor, was transferred from an outside hospital at 37 weeks’ gestation with a history of a congenital bicuspid aortic valve. The patient reports dyspnea throughout her pregnancy, and had a recent syncopal event. Subsequently, transthoracic echocardiogram revealed a mean aortic valve gradient of 45 mm Hg and an aortic valve area of 1.2 cm2.
8. Two hours later, she endorses abdominal pain (8/10) and is requesting analgesia. The most appropriate option for her pain management during labor and delivery is
A. Spinal anesthetic with bupivacaine
B. Epidural anesthesia with adequate volume preloading
C. Inhaled nitrous oxide
D. Oral analgesics
9. Despite an appropriate increase in her cardiac output and plasma volume, her systemic blood pressure does not increase during the course of her pregnancy because of
A. Decrease in systemic vascular resistance
B. Compression of the vena cava
C. Decrease in venous capacitance
D. Decrease in heart rate
10. Iatrogenic contributions to maternal supine hypotension syndrome can be minimized by
A. Left hip elevation
B. Left-uterine displacement
C. Regional anesthesia
D. General anesthesia
11. The most significant change in maternal lung volume that occurs in the third trimester of pregnancy includes
A. Decrease in vital capacity
B. Increase in residual volume
C. Decrease in functional residual capacity (FRC)
D. Decrease in closing capacity (CC)
12. Which of the following is not associated with oxytocin administration?
A. Myocardial ischemia
B. Respiratory depression
C. Hypotension
D. Tachycardia
13. During maintenance of a general inhaled anesthetic for an urgent nonobstetric surgery, one would expect this difference in the pregnant patient versus a nonpregnant patient:
A. Slower emergence from anesthesia
B. Minimal changes in depth of anesthesia
C. There is to be no difference
D. Faster induction of anesthesia
14. When providing general anesthesia during pregnancy, minimum alveolar concentration (MAC) is
A. Increased
B. Decreased
C. Unchanged
D. Unclear
15. The speed of time to hypoxia following apnea is faster in the late-trimester parturient due to all of the following factors, except
A. Reduced functional residual capacity
B. Increased minute ventilation
C. Preoxygenation
D. Increased oxygen consumption
16. The correct respiratory physiologic change associated with pregnancy is
A. Increase in arterial pH
B. Increase in HCO3
C. Increase in PaCO2
D. Increase in tidal volume
17. The P50 for maternal hemoglobin
A. Increases due to elevated levels of 2,3-diphosphoglycerate (DPG)
B. Remains unchanged
C. Increases to maintain pH
D. Decreases to enhance oxygen delivery to tissues
18. At sea level, the most likely arterial blood gas (ABG) sample of a parturient at 35 weeks’ gestation when she rests in the supine position breathing room air is
A. pH = 7.35, PaO2 = 90, PaCO2 = 45, HCO3 = 20
B. pH = 7.40, PaO2 = 100, PaCO2 = 40, HCO3 = 24
C. pH = 7.44, PaO2 = 90, PaCO2 = 30, HCO3 = 20
D. pH = 7.50, PaO2 = 105, PaCO2 = 30, HCO3 = 20
19. A 27-year-old G2P1 at 392 weeks’ gestation is electing to have spinal anesthesia for a repeat cesarean section. Five minutes after bupivacaine spinal injection, the patient becomes hypotensive and is complaining of tingling in her fingers with subjective difficulty breathing. Her oxygen saturation remains 100% and blood pressure is 95/55. The most likely etiology is
A. Engorgement of epidural veins contributed to inadvertent intravascular injection of the local anesthetics
B. Decrease in volume of CSF in the subarachnoid space facilitated higher spread of local anesthetics
C. Severe patient anxiety
D. Increased peripheral nerve sensitization to local anesthetics
20. During pregnancy, hepatic changes contribute to
A. Decreased albumin levels contributing to higher free blood levels of highly protein-bound drugs
B. Decreased liver function tests due to decreased blood flow
C. Decreased concentration levels of coagulation factors leading to easy bruisability
D. Decreased activity of plasma cholinesterase resulting in significantly longer duration of action of succinylcholine
Questions 21 to 23
After 18 hours of laboring and adherence to a strict nonpharmacologic natural birth plan, the patient experiences late decelerations and fetal distress, requiring emergent cesarean section.
21. To minimize the risk of aspiration and resultant pneumonitis,
A. Place patient in left-uterine displacement
B. Give H2-receptor antagonist to decrease the pH of gastric fluid present in the stomach
C. Give metoclopramide to reverse opioid-induced gastric hypomotility
D. Give a nonparticulate antacid to decrease the pH of the gastric fluid
22. The most common cause of late decelerations in fetal heart rate (FHR) (down to 90 bpm) is
A. Fetal vagal reflex
B. Compression of the fetal head
C. Umbilical cord compression
D. Fetal alkalosis
23. After performing a single-shot intrathecal anesthetic consisting of 7.5 mg of preservative-free bupivacaine and 25 μg of fentanyl, the surgical incision is made and systemic hypotension (78/44 mm Hg) ensued. To avoid significant decreases in uterine blood flow, first-line therapy to consider is
A. Provide additional inhaled nitric oxide (NO) to vasodilate the uterine vasculature
B. Increase maternal cardiac output with use of epinephrine
C. Increase intravascular volume with fluids
D. Use reverse Trendelenburg to decrease aortocaval compression
Questions 24 to 25
With increasing concern of variable decelerations, a male fetus is delivered with vacuum assistance. The amniotic fluid was noted to be meconium stained. Initial evaluation reveals a cyanotic limp infant with a heart rate of 80 bpm, poor respiratory efforts, and grimacing in response to suctioning.
24. Patient’s Apgar score would be
A. 0
B. 3
C. 5
D. 10
25. Appropriate initial steps in the resuscitation efforts would include all of the following, except
A. Tracheal suctioning
B. Provide radiant heat source
C. Positive-pressure ventilation
D. Supplemental oxygen
26. Regarding forceps-assisted delivery
A. High-forceps delivery has the highest success rate
B. Prevents clavicle fracture associated with dystocia
C. Hastens postpartum maternal recovery
D. Is associated with increased incidence of fetal facial nerve trauma
27. True statement regarding fetal circulation includes
A. The ductus venosus shunts blood away from the pulmonary circuit.
B. Deoxygenated blood is carried in the umbilical vein.
C. The foramen ovale shunts blood from right to left ventricles.
D. Intracardiac pressures are equalized across both right and left ventricles.
28. Successful transition from fetal to neonatal circulation is required after birth to support extrauterine life. This depends primarily on these factors, except
A. Removal of the placenta
B. Decreased systemic vascular resistance
C. Decreased pulmonary vascular resistance
D. Closure of the intra- and extracardiac shunts
29. In considering placental exchange and fetal uptake, all statements are true, except
A. Minimizing the maternal blood concentrations of a drug is the most important method of limiting the amount that ultimately reaches the fetus
B. Drugs that readily cross the blood–brain barrier will also cross the placenta
C. Placental exchange of substance occurs principally via ion transport from the maternal circulation to the fetus
D. Ion trapping explains why fetal-to-maternal lidocaine ratios are higher during fetal acidemia than during normal fetal well-being
30. Which of the following best explains why lidocaine has a higher fetal-to-maternal plasma ratio when compared with bupivacaine?
A. Bupivacaine has a smaller molecular weight
B. Lidocaine has higher protein-binding
C. Bupivacaine has a lower dissociation constant (pKa)
D. Lidocaine is less lipid soluble
31. In order to provide analgesia for all stages of labor, one must accommodate the evolving and varied course of labor and delivery. The least accurate statement regarding the anatomy of labor is
A. Pain during labor and delivery is often described in two stages
B. Somatic and visceral innervation of the uterus and cervix enters the spinal cord via T10 to L1
C. Innervation of the perineum is primarily via the pudendal nerve
D. Somatic and visceral afferent sensory fibers from the uterus and cervix travel with greater, lesser, and least splanchnic nerves via the celiac plexus
32. The regional or neuraxial technique that would not be expected to provide appropriate analgesic benefit during the first stage of labor is
A. Lumbar epidural
B. Pudendal nerve block
C. Lumbar sympathetic block
D. Paracervical block
Questions 33 to 37
A 37-year-old G9P4 patient at 38 weeks of gestation presents for management of labor and delivery. She denies any medical history and admits to minimal prenatal care. The patient is moderately hypertensive (160/95) with associated pitting edema at her ankles.
33. The statement about her disorder that is most likely true is
A. Eclampsia is imminent
B. Preeclampsia is a syndrome manifested after the 36th week of gestation
C. HELLP syndrome is the mildest form of eclampsia
D. Definitive treatment of preeclampsia is delivery of the fetus and placenta
34. The patient is started on oxytocin to augment her labor, and the patient is now requesting a labor epidural. Anesthetic considerations include
A. The presence of hypertension and edema requires further workup before proceeding
B. No workup is required prior to performing epidural anesthesia, as this will treat her hypertension
C. Neuraxial anesthesia should be avoided, as there is increased risk of bleeding
D. Avoid systemic opiates, as the risk of respiratory depression is too high
35. After a review of her laboratory results, a lumbar (L3–L4) epidural was placed without incident (including lack of CSF, and negative test dose after administration of 45 mg lidocaine with 1:200,000 epinephrine). Epidural anesthesia is then initiated with a bolus of 15 mg of bupivacaine. Variable decelerations are noted minutes later on fetal heart rate monitoring. If scalp pH reveals fetal acidosis, compared with a normal pH, the anesthetic absorbed by the fetus will be present in
A. Higher concentration, most in ionized form
B. Lower concentration, most in ionized form
C. Higher concentration, most in unionized form
D. Unchanged concentration, equal fraction of ionized and nonionized
36. The patient has now been receiving a dilute infusion (bupivacaine 0.125% with 2 μg/mL fentanyl) for the past 3 hours and reports good pain relief with a bilateral T5 sensory level. Her blood pressure is now 85/45 mm Hg, and her heart rate is 120 bpm. The fetal heart rate pattern begins to show late decelerations. The most appropriate management in this patient includes
A. Immediate bedside cesarean delivery
B. Administration of phenylephrine
C. Administration of ephedrine
D. Discontinuation of the epidural infusion
37. As augmentation of labor continues, patient’s blood pressure slowly climbs again, with waning epidural analgesic benefit. Highest pressure was noted to be 166/112 mm Hg with heart rate sustained over 100 bpm. The most appropriate pharmacologic option for acute treatment of severe hypertension in a preeclamptic patient is
A. Magnesium
B. Dopamine
C. Labetalol
D. Hydralazine
38. Four hours postdelivery, and after the epidural is removed, the patient now requires emergent anesthesia for surgical removal of retained placental products. The appropriate anesthetic management includes all of the following, except
A. Antibiotic administration
B. Total intravenous anesthesia
C. General endotracheal inhaled anesthetic
D. Sodium citrate
39. Forty-eight hours postdelivery, the patient is febrile, complaining of chills with severe occipital and neck pain worsened with sitting and standing, but not improved when lying in bed. The finding you would not expect to find on examination is
A. Urinary retention
B. Low back pain
C. Nausea and vomiting
D. Normal white blood cell (WBC) count
40. Postdural puncture headache (PDPH) occurs more frequently
A. In elderly (>50 year old) vs. young patients
B. In underweight vs. overweight patients
C. With a cutting-point vs. pencil-point spinal needles
D. With larger- vs. smaller-gauge spinal needles
41. Decrease in fasciculations can be seen following induction doses of succinylcholine for emergent cesarean section. The factor that can blunt this response is
A. Increased cardiac output
B. Prior magnesium administration
C. Prior nitrous oxide inhalation
D. Metabolic alkalosis
42. Administration of all the following will provide uterine relaxation, except
A. Sevoflurane
B. Nitrous oxide
C. Nitroglycerine
D. Terbutaline
43. Adverse effects of inhaled β-tocolytic therapy for preterm labor to the mother include all of the following, except
A. Hypoglycemia
B. Pulmonary edema
C. Tachycardia
D. Ventricular arrhythmias
44. During a general anesthetic for emergent cesarean section, administering of all of the following could contribute to increased operative blood loss, except
A. Nitroglycerine
B. Ritodrine intravenously
C. 1 MAC Desflurane
D. Hyperventilation
45. With regard to sodium thiopental, the following statements are accurate, except
A. Peak concentration in the brain occurs at 1 minute postinjection
B. Rapid redistribution allows for return of consciousness in <10 minutes
C. Infusions maintain appropriate surgical conditions with fast recovery due to ultra-short action
D. Repeating the induction dose results in fetal depression
46. The following statements are true regarding umbilical cord blood, except
A. Provides a picture of the acid–base balance in the infant at the moment of birth
B. Double clamping of the umbilical cord at birth will preserve a segment of cord blood in isolation, which can remain stable for up to 24 hours
C. Cord blood that is still in continuity with the placenta will have shifting acid–base balance due to ongoing placental metabolism and gas exchange
D. Normal paired arterial and venous specimens can provide evidence against an intrapartum hypoxic–ischemic event to the newborn
47. Maternally administered drugs that decrease beat-to-beat variability of fetal heart rate include all of the following, except
A. Ritodrine
B. Atropine
C. Prochlorperazine
D. Bupivacaine
48. A 24-year-old G4P2 parturient is undergoing a general anesthetic for emergency cesarean section due to uterine rupture. All these findings would suggest an amniotic fluid embolism (AFE), except
A. Decreased EtCO2
B. Increased maternal pH
C. Bleeding diathesis
D. Upsloping EtCO2 tracing
49. A 42-year-old G1P0 at 294 weeks’ gestation is undergoing intracranial clipping of a large arteriovenous malformation, following sudden onset of a severe headache with associated nausea/vomiting. Patient is intubated in the interventional radiology suite and ventilated with settings of TV = 500 mL, respiratory rate = 14 bpm, PEEP = 5 cm H2O, and FIO2 = 1.0. Arterial blood gas (ABG) 30 minutes later reveals pH = 7.55, PaO2 = 502, PaCO2 = 19, and HCO3 = 21. These findings are associated with all of the following, except
A. Decreased fetal cerebral oxygen delivery
B. Decreased placental transfer of oxygen
C. Rightward shift of the oxygen dissociation curve
D. Decreased umbilical blood flow
50. True statement concerning hyperglycemia during pregnancy is
A. Increases risk of fetal microsomia
B. Fetal oxygen requirements remain decreased
C. May contribute to neonatal hypoglycemia
D. Increases risk of sepsis during cesarean delivery
51. True statement regarding neuraxial opioids for labor and delivery is
A. Opioids should never be used as a sole agent
B. Most common side effect is fetal bradycardia
C. Intrathecal morphine is associated with quick peak in concentration and early onset maternal respiratory depression
D. Systemic absorption is similar to intramuscular (IM) administration
52. All of the following drugs readily cross the placenta, except
A. β-Agonist antagonists
B. Local anesthetics
C. Insulin
D. Morphine
53. Following a 0.6 mg/kg intravenous dose of rocuronium to facilitate rapid-sequence induction in a parturient requiring surgical delivery, one would expect
A. Minimal placental transfer of rocuronium to the newborn
B. Shorter duration of relaxation with concurrent magnesium administration
C. Unsuitable intubating conditions as recommended doses are 1.5 mg/kg
D. Use of rocuronium has been shown to affect Apgar scores and fetal muscle tone at birth and should be strictly avoided
54. During cesarean section under general endotracheal anesthesia, venous air embolism (VAE)
A. Is associated with high end-tidal CO2
B. Should be treated with nitrous oxide
C. Is associated with expired nitrogen
D. Induces severe hypertension
Questions 55 to 58
A 30-year-old otherwise-healthy G2P0 (167 cm, 68 kg) presents at 341 weeks’ gestation with the rupture of membranes, single footling in breech presentation with fetal bradycardia. The decision for emergent cesarean delivery under general anesthesia is made, and the patient is quickly prepared for a rapid sequence induction. However, patient’s larynx is noted to be very anterior, and is unable to be intubated after multiple direct laryngoscopy attempts.
55. The appropriate next step considering persistent fetal bradycardia (<80 bpm) is
A. Administer 1 mg/kg of rocuronium intravenously
B. Use bag-mask ventilation and allow surgical delivery to proceed
C. Wake the patient up for awake fiberoptic intubation
D. Reposition the patient in Trendelenburg with left-uterine displacement
56. The fetus is quickly delivered (skin-to-skin time of 18 minutes). However, 10 minutes after delivery, her uterus is noted to be boggy and bleeding persists. The appropriate treatment option is
A. Bolus oxytocin (Pitocin) 20 U intravenously
B. Bolus methylergonovine (Methergine) 0.2 mg intravenously
C. Misoprostol (Cytotec) 800 mg intramuscularly
D. 15-Methyl PGF2α (Hemabate) 0.25 mg intramuscularly
57. Two hours later, the patient remains apneic and intubated in the intensive care unit. She is sedated and mechanically ventilated (TV = 450, RR = 12, FIO2 = 0.4) with the arterial blood gas revealing a pH of 7.45, PaO2 of 100 mm Hg, and PaCO2 of 37 mm Hg with a base excess of zero. Her examination reveals absent deep-tendon reflexes throughout. ECG reveals intermittent ventricular bigeminy. This situation could be explained by
A. Hypermagnesemia
B. Severe hypovolemic shock
C. Hypocalcemia
D. Pituitary necrosis
58. At 3 weeks’ postpartum, the patient has absence of lactation and denies return of her menstrual cycle. Review of systems is positive for intolerance to cold, constipation, hair loss, and 2-pound weight gain. The best explanation for this constellation of symptoms is
A. Amenorrhea–galactorrhea syndrome
B. Sheehan syndrome
C. Fibromyalgia
D. Meigs syndrome
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