CHAPTER 41 | Obstetric Anesthesia Flashcards
Which of the following is INACCURATE during term pregnancy:
A. gastric emptying is not delayed during pregnancy or early labor
B. BP should be monitored frequently (every 2 to 3 minutes) after the induction of neuraxial
anesthesia
C. Cardiac output is highest immediately post partum
D. Flow volume loop is decreased
E. Arterial CO2 tension is increased
E. Arterial CO2 tension is increased
Hypotension after spinal anesthesia is common due to sympathetic blockade. Which of the following agents results in LESS fetal acidosis:
A. Phenylephrine
B. Ephedrine
C. Norepinephrine
D. Epinephrine
A. Phenylephrine
Phenylephrine is equally efficacious to ephedrine for treating maternal hypotension and results in less fetal acidosis; thus, phenylephrine is
preferred for the prevention and treatment of neuraxial anesthesia-induced
hypotension in pregnancy.
Can you give Norepinephrine as a bolus in spinal anesthesia-induced hypotension?
If yes, what is the suggested bolus dose according to BARASH?
YES. The suggested dose is 6ug
Because phenylephrine may result in reflex bradycardia and decreased CO, some experts have proposed using norepinephrine to prevent and treat hypotension due to its β-adrenergic agonist effects.
The relative potency of norepinephrine to phenylephrine is approximately 11:1, and thus the
suggested dose of IV bolus norepinephrine for this indication is 6 μg.
What is the underlying cause of this CTG tracing?
A. Head compression
B. Uteroplacental insufficiency
C. Cord compression
D. Fetal acidosis
A. Head compression
This shows EARLY DECELERATIONS
Early Deceleration > Head compression
Variable Deceleration > Cord Compression
Late Deceleration > Uteroplacental insufficiency
What is the underlying cause of this CTG tracing?
A. Head compression
B. Uteroplacental insufficiency
C. Cord compression
D. Fetal acidosis
B. Uteroplacental insufficiency
This shows LATE DECELERATIONS
Early Deceleration > Head compression
Variable Deceleration > Cord Compression
Late Deceleration > Uteroplacental Insufficiency
A category I fetal heart rate has:
A. Minimal variability +/- early decelerations
B. Moderate variability +/- early decelerations
B. moderate variability ± early decelerations
NORMAL ACID BASE status
Peak effect of Betamethasone:
A. 24 hrs
B. 48 hrs
C. 12 hrs
B. 48 hrs
TRUE or FALSE
Continuous epidural infusion of lidocaine is associated with a higher incidence of ‘Tachyphylaxis.’
TRUE
TRUE or FALSE
Being pregnant doesn’t increase the risk of developing PDPH.
FALSE
Pregnant is PDPH risk!
By virtue of age and sex, pregnant patients are at HIGHER risk for developing PDPH
In addition, after delivery, reduced pressure in the epidural space may increase the risk of cerebrospinal fluid leakage through a dural puncture, and estrogen withdrawal after delivery of
the placenta may exacerbate vascular headaches.
Meningitis is a rare complication after spinal or epidural anesthesia. If clinically suspected, the most common pathogen is:
A. staph. aureus
B. strep. viridans
C. staph. epidermidis
B. strep. viridans
Infections are rare; epidural abscess is usually
caused by skin contaminants and meningitis by contamination of drugs or needles with clinicians’ nasopharyngeal flora (streptococcus viridans).
At the ER, you called a code blue on a full term G2P1001. The resuscitation measures failed after several attempts and the OB decided to do a perimortem cesarean section. When is the golden period to perform perimortem CS?
A. within 5 minutes of the cardiac arrest
B. within 2 minutes of the cardiac arrest
C. CS hysterectomy should be done within 30 mins after the arrest
A. within 5 minutes of the cardiac arrest
In the event of maternal cardiac arrest, cardiopulmonary resuscitation should be initiated immediately.
If return of spontaneous circulation is not achieved with the usual resuscitation measures, perimortem
cesarean delivery should be performed, ideally within 5 minutes of the cardiac arrest.
The patient should not be moved to an operating room to perform the hysterotomy, as this wastes valuable time. Rather, the delivery should be performed at the site of the arrest.
Advanced maternal age is defined as:
> 35 year old at the time of delivery
Which of the following drugs does NOT pass the placenta easily?
A. Etomidate
B. Ephedrine
C. Atropine
D. Glycopyrrolate
D. Glycopyrrolate
Magnesium sulfate (MgSO4 ) is used as an anticonvulsant in patients with preeclampsia and for fetal neuroprotection and sometimes for short-term tocolysis. MgSO4 may produce any of the following effects EXCEPT:
A. Sedation
B. Respiratory paralysis
C. Inhibition of acetylcholine (ACh) release at the myoneural
junction
D. Hypertension when used with nifedipine
D. Hypertension when used with nifedipine - FALSE NOTION
Because magnesium antagonizes the effects of α-adrenergic agonists, ephedrine is usually preferred over phenylephrine if a vasopressor is needed to restore blood pressure, along with fluids, after a neuraxial blockade. When a calcium channel blocker, such as nifedipine, is administered along with magnesium, greater hypotension has resulted.
Cardiac output increases dramatically during pregnancy and delivery. The
cardiac output returns to nonpregnant values by how long postpartum?
A. 12 hours
B. 1 day
C. 2 weeks
D. 6 months
C. 2 weeks
Each uterine contraction increases the cardiac output by about:
A. 10 -25%
B. 5%
C. 30 - 40%
A. 10 -25%
What is therapeutic range of Magnesium Sulfate:
A. 4 to 8 mEq/L
B. 10 mEq/L
C. 2 - 3 mEq/L
D. 15 - 20 mEq/L
A. 4 to 8 mEq/L
With increasing serum levels, loss of deep tendon reflexes occurs at 10 mEq/L (12 mg/dL),
respiratory paralysis occurs at 15 mEq/L (18 mg/dL), and cardiac arrest at greater than 25 mEq/L (> 30 mg/dL) can occur.
Magnesium decreases the release of ACh at the myoneural junction and decreases the sensitivity of the motor endplate to ACh. This can produce marked potentiation of nondepolarizing muscle relaxants.
A 24-year-old primiparous woman is undergoing an elective cesarean section (breech position). After prehydration with 1500 mL of saline, a spinal
anesthetic is performed; 5 minutes later, the blood pressure is noted to be 80/40 mm Hg and the heart rate is 110 beats/min.
The BEST treatment (best fetal pH) after ensuring that adequate left uterine displacement is performed would be:
A. Phenylephrine
B. Ephedrine
C. Epinephrine
D. 1000 mL 5% dextrose in lactated Ringer solution
A. Phenylephrine
In this patient who has left uterine displacement, adequate IV hydration, and a heart rate of 110
beats/min, phenylephrine would be the preferred vasopressor. If the mother has hypotension with bradycardia, ephedrine might be a better choice.
Epinephrine is rarely needed but should be available and used when there is severe hypotension that is not responsive to phenylephrine or ephedrine, especially when there is associated fetal bradycardia.
What is the P50 of fetal hemoglobin at term?
A. 12 mm Hg
B. 18 mm Hg
C. 24 mm Hg
D. 30 mm Hg
A 32-year-old parturient with a history of spinal fusion, severe asthma, and hypertension (blood pressure 180/110) is brought to the operating room wheezing. She needs an emergency cesarean section under general anesthesia
for a prolapsed umbilical cord.
Which of the following induction agents would be MOST appropriate for her induction?
A. Sevoflurane
B. Midazolam
C. Ketamine
D. Propofol
D. Propofol
When inducing general anesthesia in an asthmatic
patient, it is imperative to establish an adequate depth of anesthesia before placing an endotracheal tube. If the patient is “light,” then severe bronchospasm may occur. In patients with asthma, IV induction will work with ketamine or propofol
Ketamine is considered by many as the induction
agent of choice due to its mild bronchodilator properties, but because propofol (also a good induction agent in asthmatic patients) does not
stimulate the cardiovascular system as ketamine does, propofol would be preferred in this patient with hypertensive disorders of pregnancy.
