Random OB Q/A Flashcards
Which of the following conditions is not a component of HELLP syndrome?
A. Thrombocytopenia B. Elevated liver enzymes C. Hemolysis D. Leukopenia
D. Leudopenia
HELLP syndrome is a condition associated with pregnancy in which the patient exhibits:
- hemolysis
- elevated liver enzymes
- a low platelet count (thrombycytopenia)
Which of the following is associated with a higher risk of placenta accreta in parturients already presenting with placenta previa?
A. Pre-eclampsia B. History of multiple cesarean sections C. Substance abuse D. Pulmonary hypertension
B. History of multiple cesarean sections
Patients with placenta previa who have had one previous c-section are 20-25% more likely to have placenta accreta, (penetration of the myometrium by placental villi). After four or more c-sections, the incidence of placenta accreta increases by more than 67%.
Which of the following statements is true of a full-term parturient?
A. Basal oxygen consumption is increased by 33 percent B. The partial pressure of arterial carbon dioxide is increased C. The partial pressure of arterial oxygen is decreased D. Plasma bicarbonate increases 10 percent
A. Basal oxygen consumption is increased by 33 percent
Oxygen consumption increases by about 33 percent in the full-term parturient, but minute ventilation increases by 50 percent at term. The increased alveolar ventilation results in an increase in the PaO2 to about 106 mmHg and a decrease in the PaCO2 to about 30-32 mmHg. The plasma base (HCO3-) decreases from about 26 to 22 mEq/L, thus, the pH is essentially unchanged.
Which of the following explains why obstetric patients are at a greater risk of gastroesophageal reflux?
A. Lower esophageal sphincter tone is reduced B. Gastric volume is increased C. Gastric emptying is decreased D. Gastric pH is lower
A. Lower esophageal sphincter tone is reduced
In obstetric patients, the gastric volume, gastric emptying time, and pH of gastric contents are unchanged, but lower esophageal sphincter tone is decreased, making them more susceptible to gastroesophageal reflux.
Which of the following statements concerning respiratory changes during pregnancy is true?
A. Airway resistance is essentially unchanged B. Functional residual capacity increases C. Minute ventilation decreases D. Dead space increases
A. Airway resistance is essentially unchanged
Airway resistance stays roughly the same because of the competing effects between the relaxation of bronchiolar smooth muscle by progesterone versus factors such as upper airway edema. Minute ventilation increases significantly during pregnancy. Because dead space doesn’t change, alveolar ventilation is increased by as much as 70% at term. The FRC decreases by 20-30%.
Which of the following statements regarding the hematology studies of a full-term parturient is correct?
A. The total blood volume decreases B. The average platelet count is about 50,000 C. A relative polycythemia is present during pregnancy D. The red blood cell mass increases
D. The red blood cell mass increases
The blood volume increases as pregnancy progresses. The total increase is about 25-40% over normal values at term. Because the red blood cell mass only increases by about 20%, there is a relative anemia present.
How are thyroid hormones altered by pregnancy?
A. T3 levels decrease and T4 levels increase B. T3 levels increase and T4 levels decrease C. T3 levels decrease and T4 levels decrease D. T3 levels increase and T4 levels increase
D. T3 levels increase and T4 levels increase
Because of the estrogen-induced increase in thyroid-binding globulin, the concentrations of both the T3 (triiodothyronine) and T4 (thyroxin) concentrations increase by about 50%. Follicular hyperplasia and increased vascularity result in a 50-70% increase in the size of the thyroid gland in pregnant patients.
Which of the following changes occurs during pregnancy? (select two)
A. The left ventricular end-diastolic volume increases
B. The left ventricular end-systolic volume increases
C. Plasma renin activity increases
D. The white blood cell count decreases
C. Plasma renin activity increases
The left ventricular end-diastolic volume increases during pregnancy, but there is no change in the end-systolic volume. As a result, the ejection fraction during pregnancy is increased. Despite the increased blood volume levels, plasma renin levels are increased. The white blood cell count increases from around 6,000/mm3 to about 11,000/mm3 predominantly due to an increase in polymorphonuclear cells. The white blood cell count increases to 13,000/mm3 during labor and as high as 15,000/mm3 on the first postpartum day. Within a week postpartum, WBC levels fall to around 9,000/mm3.
Which of the following obstetric conditions likely warrants a crash induction for emergency cesarean section?
A. Persistent occiput posterior B. Arrest of descent C. Placental abruption D. Placenta previa
C. Placental abruption
Abruption of the placenta can result in massive blood loss and is one of the most common causes of fetal demise. If the abruption is mild, a vaginal delivery may be attempted, but at any sign of fetal distress an emergency cesarean section must be carried out. Arrest of descent is failure of labor to progress that may require c-section, but a crash induction is unlikely as the situation is not necessarily emergent. Persistent occiput posterior is an abnormal fetal presentation that results in prolonged and painful delivery.
All of the following ventilatory parameters remain unchanged in pregnancy except for
A. Airway resistance B. Lung compliance C. Deadspace volume D. Total lung capacity
A. Airway resistance
respiratory rate and airway resistance decreases. Deadspace volume, however, remains unchanged throughout pregnancy. Lung compliance doesn’t change. Airway resistance decreases because progesterone induces bronchiolar smooth muscle relaxation.
Which of the following statements regarding obstetric patients is true?
A. By the third trimester, cardiac output is 50-60% higher than nonpregnant values B. By the third trimester, plasma renin activity is 12 times higher than nonpregnant values C. Cardiac output is elevated for about 21 days after delivery D. Minute ventilation is one-fourth less in the third trimester than nonpregnant values
B. By the third trimester, plasma renin activity is 12 times higher than nonpregnant values
By the end of the first trimester, the cardiac output is 15-25 percent higher than nonpregnant values. Cardiac output is still elevated for 24 hours after delivery and returns to normal slowly over a period of about 10 days. Despite the increased blood volume levels, plasma renin levels are increased.
How does pregnancy affect insulin resistance?
A. Insulin resistance is increased due to the effects of lactogen
B. Insulin resistance is increased due to the effects of progesterone
C. Insulin resistance is decreased due to follicle stimulating hormone
D. Insulin resistance is decreased due to the effects of estrogen
A. Insulin resistance is increased due to the effects of lactogen
The release of the hormone lactogen by the placenta causes an increase in insulin resistance during pregnancy.
Manifestations of preeclampsia include: (select four)
A. increased colloid oncotic pressure B. hypervolemia C. oliguria D. pulmonary edema E. arterial hypoxemia F. thrombocytosis G. decreased uterine blood flow H. hypotension
C. oliguria
D. pulmonary edema
E. arterial hypoxemia
G. decreased uterine blood flow
Manifestations of preeclampsia include: hypertension, hypovolemia, oliguria, decreased colloid oncotic pressure, pulmonary edema, arterial hypoxemia, decreased uterine blood flow, disseminated intravascular coagulation, cerebral edema, cerebral hemorrhage, acute tubular necrosis, and HELLP syndrome (hemolysis, elevated liver enzymes, low platelets).
Which of the following parameters increases with pregnancy?
A. PaO2 B. PaCO2 C. HCO3 D. Total lung capacity
A. PaO2
During pregnancy, oxygen consumption increases, but the increase in minute ventilation results in an elevation in PaO2 by about 10%. The PaCO2 decreases to between 28-32 mmHg. The HCO3 level decreases about 15% as well. The total lung capacity reduces slightly during pregnancy.
Which of the following parameters normally decrease during pregnancy? (select four)
A. Platelet count B. Oxygen consumption C. Glomerular filtration rate D. Heart rate E. Peripheral vascular resistance F. Hemoglobin content in mg/dL G. Blood volume H. Functional residual capacity
A. Platelet count
E. Peripheral vascular resistance
F. Hemoglobin content in mg/dL
H. Functional residual capacity
During pregnancy, oxygen consumption and minute ventilation increase, but the functional residual capacity decreases. Both the platelet count and hemoglobin concentration decrease. The cardiac output, stroke volume, and heart rate all increase but, the systolic blood pressure, diastolic blood pressure, peripheral vascular resistance, and pulmonary vascular resistance decrease. The glomerular filtration rate increases by as much as 50%.
