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A 35-year-old heroin-addicted parturient in labor is requesting pain relief. Which of the following options is LEAST desirable? A. meperidine B. continuous epidural analgesia C. nitrous oxide D. butorphanol E. lumbar sympathetic block

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Anesthesia for in vitro fertilization can be provided with (1) pudendal block (2) intravenous sedation (3) local infiltration (4) spinal anesthesia A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

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The following statements regarding pregnancy and mitral stenosis are true except A. mitral stenosis is the most common acquired cardiac lesion presenting during pregnancy B. epidural analgesia is indicated to attenuate the increased cardiac output and tachycardia associated with the pain of labor C. ephedrine is preferred as a vasopressor D. invasive hemodynamic monitoring is indicated in cases of symptomatic mitral stenosis E. maternal expulsive efforts should be avoided during the second stage of labor

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True statements regarding amniotic fluid embolism include (1) mortality remains around 40 to 50% (2) classical signs and symptoms include abrupt onset of dyspnea, hypoxemia, cyanosis, seizures, loss of consciousness, and hypotension (3) usually occurs prior to labor (4) disseminated intravascular coagulation (DIC) and cardiac arrest are common A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

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Which of the following statements is true regarding neuraxial opioids? A. Spinal opioids augment sympathetic blockade produced by local anesthetics. B. Naloxone does not reverse nausea and vomiting caused by intrathecal opioids. C. Epidural opioids are as effective as a bupivacaine-opioid mixture in relieving pain. D. Intrathecal morphine produces approximately 24 hours of analgesia. E. Intrathecal fentanyl produces approximately 16 hours of analgesia.

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Anesthesia for emergency cesarean section can be provided by (1) general anesthesia (2) local infiltration (3) subarachnoid block (4) epidural block (if epidural catheter not already in place) A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

A. Anesthesia for an emergency cesarean section requires fast onset. Therefore, an epidural block is not appropriate. Since time is of the essence in these situations, a room with all equipment is kept ready at all times.

Anesthesia for emergency cesarean section can be provided by (1) general anesthesia (2) local infiltration (3) subarachnoid block (4) epidural block (if epidural catheter not already in place) A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

A. Anesthesia for an emergency cesarean section requires fast onset. Therefore, an epidural block is not appropriate. Since time is of the essence in these situations, a room with all equipment is kept ready at all times.

Which of the following CNS changes occur in the parturient? (1) Nerve fibers have increased susceptibility to local anesthetics. (2) MAC for inhalational agents is decreased. (3) Activation of endorphin system. (4) No change in spread of local anesthetics in subarachnoid space during first trimester. A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

A. Anesthetic requirements are decreased in pregnancy, with 25% less local anesthetic needed for regional anesthesia. Anatomic effects, such as distended epidural veins, increase spread of local anesthetics. Hormonal changes alter nerve response. Increased progesterone levels may be responsible for the 25 to 40% reduction in MAC to general anesthetics.

All of the following statements are true regarding fetal blood capillary pH testing except A. it is a method that cannot be used to assess fetal well-being during labor of a breech presentation B. a fetal scalp pH of 7.25 or higher is considered normal C. a fetal scalp pH of less than 7.20 is indicative of significant asphyxia and the need for immediate delivery D. a fetal scalp pH of 7.20 to 7.24 is intermediate and requires close monitoring and repeat sampling E. it requires adequate dilation of the cervix

A. Fetal blood capillary testing may be used to assess fetal well-being during labor. It requires adequate cervical dilation to allow for sampling of the presenting part. It may be used in both vertex and breech presentations. If the testing is intermediate, continued close monitoring and repeat sampling within 30 minutes is required if delivery has not been accomplished.

Preeclampsia is associated with A. hypovolemia B. hypernatremia C. low hematocrit reading D. hyperkalemia E. hypotension

A. In spite of the fact that patients may exhibit edema and weight gain, they are hypovolemic due to the vasoconstriction that is part of the disease. They have hypertension, hyponatremia, increased hematocrit (due to the vasoconstriction and hypovolemia), and hypokalemia.

In the anesthetic management of a patient with preeclampsia, which of the following statements is (are) true? (1) Magnesium sulfate may potentiate the duration and intensity of both depolarizing and nondepolarizing muscle relaxants. (2) General anesthesia and tracheal intubation may be more difficult due to edema of the airway and friability secondary to impaired coagulation. (3) Ketamine and ergot alkaloids should be avoided. (4) Fluid retention and oliguria result in a hypervolemic state. A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

A. Magnesium potentiates the effect of muscle relaxants by diminishing the excitability of the motor end plate to acetylcholine and depressing the excitability of the skeletal muscle membrane. Generalized edema occurs in preeclampsia secondary to maternal plasma protein depletion from endothelial damage and proteinuria. Thrombocytopenia can result in coagulopathy. This can contribute to edema and friability of the airway structures and increase the risk of difficult airway. Ketamine and ergot alkaloids can both exacerbate hypertension and are contraindicated in preeclamptic patients. Despite the presence of increased fluid and sodium retention and hypertension, patients with preeclampsia are intravascularly volume depleted due to a shift of protein and fluid from the intravascular to the extravascular compartments. (quesion book said E. is right answer but I disagree).

Maternal changes associated with preeclampsia include (1) increased cardiac output (2) decreased renal blood flow (3) decreased cerebral blood flow (4) increased hepatic blood flow A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

A. Maternal changes seen with preeclampsia include increased cardiac output, decreased renal blood flow, and decreased cerebral blood flow. The last two are reasons for some of the complications. Hepatic flow is decreased in the preeclamptic patient.

Factors which may contribute to the hypotension seen with aortocaval compression include (1) thiopental (2) epidural block (3) halothane (4) hypervolemia A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

A. Medications or techniques that decrease cardiac output or vascular resistance, such as thiopental, epidural block, or halothane, will contribute to the hypotension. Hypervolemia will counteract the problem.

Factors which may contribute to the hypotension seen with aortocaval compression include (1) thiopental (2) epidural block (3) halothane (4) hypervolemia A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

A. Medications or techniques that decrease cardiac output or vascular resistance, such as thiopental, epidural block, or halothane, will contribute to the hypotension. Hypervolemia will counteract the problem.

Neural pathways responsible for the transmission of pain during the first and second stages of labor include A. T10 to L1 and S2 to S4 B. T8 to L2 and S1 to S3 C. T6 to T12 and S1 to S4 D. T10 to L5 E. T12 to L3 and S2 to S5

A. Neural pathways responsible for the transmission of pain during the first stage of labor are visceral in nature and involve afferent pathways from T10 to L1. The pathways involved for the second stage of labor are somatic and produced by the distension of the perineum and stretching of the fascia, skin, and subcutaneous tissues and involves afferent pathways from S2 to S4 via the pudendal nerves.

The newborn infant who remains apneic (1) has an exaggerated acidosis (2) develops a PCO2 rise of 10 mmHg/min (3) has a fall in pH of 0.1 unit/min (4) can tolerate this condition without permanent damage A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

A. The newborn has an acidosis as noted previously. Any apnea at birth will aggravate this problem. Immediate resuscitation is mandatory, since the PCO2 will rise rapidly and the pH will fall.

A normal newborn has which of the following values? (1) RR 35 breaths per minute (2) PO2 60 mmHg (3) HR 120 bpm (4) systolic BP 50 mmHg A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

A. The normal newborn breathes approximately 30 to 40 breaths per minute, has a heart rate approximately 120 bpm, a systolic BP of 60 to 70 mmHg, and a PO2 of 50 to 70 mmHg.

A 25-year-old gravida 2, para 1 woman is scheduled for repeat cesarean section. Anesthetic options for epidural anesthesia include (1) 1.5 to 2% lidocaine (2) 0.5% bupivacaine (3) 3% chloroprocaine (4) 1% tetracaine A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

A. Usually 15 to 25 mL of 1.5 to 2% lidocaine, 0.5% bupivacaine, or 3% 2-chloroprocaine will give a sensory level of T4. Tetracaine is typically used only for spinal anesthesia.

Disadvantages of paracervical block include (1) fetal acidosis (2) increases in uterine contractions (3) fetal bradycardia (4) inadvertent subarachnoid block A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

B. A paracervical block can lead to fetal bradycardia and subsequent fetal acidosis. The block does not affect uterine contractions. There is no risk of subarachnoid injection.

Regional anesthesia techniques that can be used for forceps deliveries include all of the following except A. bilateral pudendal block B. paracervical block C. subarachnoid block D. caudal block E. epidural block

B. A paracervical block is good for the first stage of labor, since it helps with the pain associated with cervical dilatation. A pudendal block will provide anesthesia for the second stage and is appropriate for low forceps delivery and episiotomies. A subarachnoid block, caudal block, or epidural block also is appropriate.

A patient scheduled for an elective cesarean section prefers spinal anesthesia. Which options are acceptable? (1) 8 to 10 mg of tetracaine (2) 20 to 30 mg of lidocaine (3) 8 to 12 mg of bupivacaine (4) 30 to 40 mg chloroprocaine A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

B. A sensory level of T4 is necessary for a cesarean section, but pregnant patients have a reduced requirement for local anesthetic. Typically, 65 to 75 mg of 5% lidocaine in 7.5% dextrose gives a duration of 45 to 75 minutes, 8 to 10 mg of 1% tetracaine in an equal volume of 10% dextrose provides 120 to 180 minutes, and 8 to 12 mg of 0.75% bupivacaine in 8.25% dextrose gives 120 to 180 minutes. Chloroprocaine is not used for spinal anesthesia.

During parturition A. cardiac output is decreased B. cardiac output is increased C. stroke volume is decreased D. central venous pressure is decreased E. cardiac output remains constant

B. During parturition, the cardiac output is increased. This may be offset by the effects of the uterine weight on the vena cava, leading to decreased return and decrease in cardiac output. Central venous pressure increases.

Pudendal block for obstetrics (1) requires more drug than a saddle block (2) can provide good relief from cervical dilatation (3) does not cause vasomotor blockade (4) provides a sensory level to T11 A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

B. The pudendal block is useful for relieving pain for low forceps application and for episiotomy. It requires more drug than that used for a saddle block. There is no vasomotor blockade. The sensory loss is in the area of the perineum only.

Important considerations for breech presentation include (1) uterine relaxation (2) increased need for complete breech extraction with regional anesthesia (3) possible lengthening of second stage of labor with epidural (4) increased neonatal depression with regional anesthesia A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

B. There had been some concern about regional anesthesia preventing pregnant patients from pushing effectively, but the incidence of complete breech extraction is not increased. The second stage of labor may be slightly prolonged, but regional anesthesia provides pain relief and maximal perineal relaxation for the aftercoming head delivery.

True statements regarding breech presentation include all of the following EXCEPT A. a higher incidence of congenital abnormalities B. a lower frequency of prolapsed umbilical cord C. fetal head entrapment may necessitate the need for rapid induction of general anesthesia D. causes of breech presentation include preterm delivery, multiple gestation, and uterine anomalies E. accounts for approximately 3 to 4% of all pregnancies

B. There is a higher frequency of prolapsed cord, especially with either a double footling or complete breech presentation because the fetal head no longer occupies the lower uterine segment. A higher incidence of congenital abnormalities has been found. The fetal head is the largest presenting part and it is last to present, therefore, fetal head entrapment can occur and is a life-threatening complication of vaginal breech delivery, which may require rapid induction of general anesthesia.

The one finding present in eclamptic patients and not in preeclamptics is A. hyperreflexia B. decreased uteroplacental perfusion C. presence of seizure activity D. treatment with magnesium sulfate E. general vasoconstriction

C. All the findings are present in preeclampsia and eclampsia, except the presence of seizure activity defines eclampsia.

True statements concerning continuous epidural infusion include (1) there is an increased incidence of motor block compared to intermittent boluses (2) bupivacaine 0.125% is frequently used (3) there is no advantage of adding opioids to the local anesthetic solution (4) a potential complication is migration of the catheter A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

C. Continuous epidural infusions are very popular because of the consistent pain relief with minimal side effects. Low concentrations of bupivacaine (0.0625 to 0.125%) with 2 mcg/mL of fentanyl is probably the most common solution in use. The addition of opioids allows for a lower concentration of local anesthetic and provides better analgesia than local anesthetic alone.

After a spinal anesthetic, a parturient becomes hypotensive. The drug(s) of choice for treatment is (are) (1) norepinephrine (2) phenylephrine (3) dopamine (4) ephedrine A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

C. Ephedrine increases blood pressure without decreasing uterine blood flow. Drugs with primarily -adrenergic activity may increase uterine vascular resistance and decrease uterine blood flow. Recent studies in humans have shown phenylephrine to be as safe as ephedrine.

Magnesium sulfate A. does not cross the placenta B. has therapeutic levels between 6 and 8 mEq/L C. may produce respiratory depression in the neonate D. is a CNS stimulant E. decreases sensitivity to NMB agents

C. Magnesium sulfate is given to prevent seizures. A loading dose of 4 g is given followed by an infusion of 1 to 2 g/h to achieve a blood level of 4 to 8 mEq/L. It reduces the muscle membrane excitation, decreases sensitivity to acetylcholine, and potentiates all NMB agents. It crosses the placenta and can cause respiratory depression in the newborn.

Prophylactic measures taken to prevent maternal hypotension following spinal anesthesia include all of the following except A. administration of 500 to 1000 mL of fluid before induction B. lateral displacement of the uterus C. head-down tilt immediately after injection D. placing the patient on her side after block is established E. infusion of vasopressor

C. Methods to prevent maternal hypotension include fluid administration, lateral displacement of the uterus, placing the patient on her side, and infusion of a vasopressor. A head-down tilt will increase the level of the block and make the hypotension worse.

Which of the following statements regarding drug effects in the peripartum is true? A. Benzodiazepines can prolong labor. B. Barbiturates cause no neonatal depression. C. Ketamine adversely affects uterine blood flow. D. An advantage of butorphanol is absence of respiratory depression. E. Morphine produces more respiratory depression of the newborn than does meperidine in equianalgesic doses.

C. Opioids may inhibit labor if given prior to the active phase, benzodiazepines have no effects on labor, though they are often avoided because of their amnestic properties as well as potential for neonatal depression. Barbiturates may have protracted effects on the newborn. Agonist-antagonist opioids have a ceiling effect on respiratory depression after a certain dose.

During parturition A. vital capacity (VC) decreases B. minute ventilation is unchanged C. functional residual capacity (FRC) decreases D. forced expiratory volume in 1 second (FEV1) decreases E. tidal volume (TV) decreases

C. Oxygen demand increases with pregnancy. Minute ventilation doubles as a result of increased respiratory rate and TV. There is no or minimal change in FEV1 and VC, and there is a decrease in FRC

True statements regarding antepartum hemorrhage include all of the following except A. vaginal delivery may be attempted in select cases of placental abruption B. blood loss may be underestimated in the case of placental abruption C. placenta previa characteristically presents as painful vaginal bleeding D. a case of placenta previa can usually be diagnosed by ultrasound E. may present acutely during VBAC (vaginal birth after cesarean section) secondary to uterine rupture

C. Placenta previa classically presents as painless, bright red bleeding during pregnancy. Small placental abruptions may deliver vaginally as long as there is no evidence of fetal distress. The amount of blood loss may be underestimated in placental abruption because it is often concealed behind the placenta. Unlike placental abruption, placenta previa can usually be detected by ultrasound. Uterine rupture is a rare but potentially catastrophic event requiring immediate cesarean section, possible hysterectomy and full resuscitative measures of both mother and fetus.

Early decelerations are typically associated with A. cord compression B. placental insufficiency C. head compressions D. acute fetal asphyxia E. tetanic contraction

C. The early deceleration pattern is seen with fetal head compression, which leads to increased vagal tone. Cord compression leads to variable decelerations, whereas placental insufficiency leads to late decelerations.

The pregnant woman at term A. shows no anatomic changes in the respiratory system B. is primarily a nose breather C. is primarily a mouth breather D. is less susceptible to hypoxia E. has decreased oxygen consumption

C. The pregnant patient at term is a mouth breather, since nasal congestion and swelling make it more difficult to breathe through the nose. Placement of nasal catheters or airways may lead to bleeding. The FRC is decreased at term, making the patient more prone to hypoxia. There is an increase in oxygen consumption.

Variable decelerations are usually associated with A. uteroplacental insufficiency B. head compression C. cord compression D. severe fetal asphyxia E. prematurity

C. There are three major types of fetal decelerations. Early decelerations demonstrate a slow drop in heart rate beginning with the uterine contraction (UC) with the nadir coinciding with the peak of the UC. It returns to baseline by the end of the UC. It is a result of vagal stimulation secondary to head compression and is not indicative of fetal asphyxia. Late decelerations begin after the UC and return to baseline after the end of the UC. They are often repetitive and associated with decreased fetal heart rate variability. They are associated with uteroplacental insufficiency. Variable decelerations are variable in configuration and bear no consistent temporal relationship to the onset of the UC. They are thought secondary to cord compression and unless severe and repetitive are not thought to be indicative of fetal compromise.

Regional anesthesia is contraindicated in A. vaginal birth after cesarean B. abruptio placentae C. diagnosis of placenta previa D. thrombocytopenia and an elevated bleeding time E. eclampsia

D. Even though there had been some concern about masking symptoms and signs of uterine rupture in patients at risk during a vaginal birth after cesarean, this has not been the case if fetal heart rate and uterine activity are continuously monitored. DIC has been associated with abruptio placentae, but if clotting studies and platelet counts are normal, regional anesthesia may be performed. If bleeding is minimal or absent in a patient with placenta previa, regional anesthesia is an option. In a patient with eclampsia and normal clotting studies and platelet count, epidural anesthesia is an option as long as blood pressure is well maintained.

During delivery, a lower dose of local anesthetic is required for regional anesthesia because A. pregnant women have greater pain tolerance B. the pain fibers are more superficial in the spinal canal C. the epidural and subarachnoid spaces are larger D. the epidural and subarachnoid spaces are decreased in size E. maternal hyperventilation decreases pain

D. Less local anesthetic is needed in the later stages of pregnancy, since the epidural space is decreased in size. This is due to the venous congestion caused by the weight of the uterus. In addition, there are studies showing that the nerves are more sensitive to the local anesthetics. This is thought to be a hormonal effect.

Uterine atony may be treated with all the following except A. uterine massage B. intramuscular methergonovine C. intrauterine prostaglandin F2 D. intravenous methergonovine E. intravenous oxytocin

D. Methergonovine is not approved for intravenous injection; all other agents are useful to treat uterine atony. Rapid infusion of oxytocin can cause hypotension, methergonovine can cause hypertension, and prostaglandin F2 can cause bronchoconstriction and hypertension.

A parturient is diagnosed with retained placenta after delivery and requires manual exploration of the uterus. All of the following are acceptable alternatives except A. intravenous analgesia B. epidural analgesia C. saddle block D. intravenous nitroglycerine, 400 mcg E. induction of general anesthesia with 1 mg/kg ketamine

D. Small doses of nitroglycerine (50 to 100 mcg) have been shown to relax the uterus to allow for manual extraction of the placenta. Caution should be used with the use of regional anesthesia in the presence of significant postpartum bleeding to avoid hypotension. Ketamine is a good induction drug in the presence of maternal bleeding, but has been shown to produce a dose-related increase in uterine tone.

When compared to spinal anesthesia, epidural anesthesia (1) permits less control (2) causes more hypotension (3) is more apt to cause spinal headache (4) carries less risk of arachnoiditis A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

D. The epidural technique is more controllable and causes less hypotension than the spinal technique. There is much less risk of postdural puncture headache. The incidence of arachnoiditis is decreased with the epidural approach.

Nerve injury during labor and delivery can result from all of the following except A. compression of lumbosacral trunk by the head of fetus B. peroneal nerve injury by lithotomy stirrup C. epidural hematoma secondary to block D. femoral nerve compression by the lithotomy stirrup E. chemical contamination of the subarachnoid space

D. The most common cause of neurologic injury during labor and delivery is secondary compression of the lumbosacral trunks by the fetal head. Incorrect positioning can cause peroneal nerve injury secondary to the lithotomy stirrups if the legs are positioned to the inside. Femoral nerve compression can occur secondary to excessive flexion of the hip in the lithotomy position. Epidural hematomas and chemical contamination of subarachnoid space are fortunately rare complications.

Measures to prevent aspiration pneumonia include all of the following except A. administration of an antacid before delivery B. rapid intubation C. rapid induction D. determination of the last time the patient has eaten E. cricoid pressure

D. The obstetric patient is treated as a patient with a full stomach, so the history of no recent food intake is not important. If a general anesthetic is needed, the patient should have antacids and rapid sequence induction with cricoid pressure.

Serious risks of general anesthesia in obstetric patients include (1) aspiration pneumonia (2) depression of the newborn (3) impaired uterine contractility (4) hemorrhage A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

E. All of these factors may be problems in the obstetric patient for general anesthesia. Steps must be taken to avert the problems when possible. In some patients, general anesthesia is the best approach. One must use the lowest dose of anesthesia possible and take steps to avoid aspiration. The possibility of hemorrhage must be borne in mind; all volatile anesthetics impair uterine contractility and may therefore potentiate postpartum bleeding.

True statements regarding methods employed to decrease the risk of toxicity from intravascular injection of local anesthetic during administration of an epidural include (1) aspiration of the catheter prior to injection (2) the use of 3 mL of 1.5% lidocaine with 1:200,000 epinephrine (test dose) to detect an increase in maternal heart rate or subjective symptoms (3) fractionation of the dose of local anesthetic (4) rapid administration of 1 to 2 mL of air with simultaneous Doppler monitoring of the precordium A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

E. Large doses of local anesthetics may be given during regional anesthesia for obstetrics, which can result in adverse reactions. The use of a test dose containing 15 mcg of epinephrine is still advocated by some. Objections include false positives due to uterine contractions and the theoretical concern that epinephrine may reduce uteroplacental perfusion. Fractionation helps to reduce potential toxicity. Epidural catheters should always be aspirated prior to injection. Some authors advocate the use of air as a means to detect intravascular injection.

Magnesium sulfate (1) decreases excitability of muscle membranes (2) decreases sensitivity of the motor endplate to acetylcholine (3) potentiates both depolarizing and nondepolarizing neuromuscular junction blocking agents (4) acts as a mild vasodilator A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

E. Magnesium sulfate is administered to prevent seizures. The loading dose is 4 g over 10 minutes followed by continuous infusion of 1 to 2 g/h to achieve a blood level of 4 to 6 mEq/L. In addition to all the properties listed, magnesium sulfate decreases acetylcholine release.

The following techniques can all be employed to relieve pain during first stage of labor except A. paracervical block B. epidural anesthesia C. spinal anesthesia D. lumbar sympathetic block E. pudendal block

E. Pain during the first stage of labor is caused by uterine contractions and cervical dilatation. All the techniques listed can be beneficial except pudendal block, which only supplies the lower vaginal canal and perineum through sacral roots S2 to S4.

Placental circulation may be decreased by (1) uterine contractions (2) maternal hypotension (3) aortoiliac compression (4) hemorrhage A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

E. Placental circulation is decreased by uterine contractions. This is part of normal labor. If tetanic contractions occur, the fetal circulation may be seriously impaired. Hemorrhage may lead to maternal hypotension, which may decrease uterine blood flow. Aortoiliac compression may decrease uterine blood flow directly, and if vena cava compression occurs with it, the hypotension will aggravate the problem.

Cholinesterase levels during pregnancy are A. highest at term B. unchanged from normal levels C. increased D. decreased resulting in a clinically significant prolongation of amide type local anesthetics E. decreased to a level not resulting in a clinically significant prolongation of the action of succinylcholine in the doses generally given

E. Plasma cholinesterase levels are typically decreased by 25% during pregnancy. The decreased levels do not result in clinically significant effects on ester-type local anesthetics or succinylcholine in the doses generally used.

A woman has been in labor for 2 hours when her membranes rupture and the umbilical cord is prolapsed. Her treatment should include (1) breech extraction or forceps extraction if the cervix is fully dilated (2) knee-chest position (3) constant monitoring of fetal heart tones (4) immediate cesarean section if delivery is not imminent A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

E. Prolapse of the umbilical cord is a true obstetric emergency. Steps should include all of the options. This can occur without warning, and one must always be prepared for such an emergency.

A woman has been in labor for 2 hours when her membranes rupture and the umbilical cord is prolapsed. Her treatment should include (1) breech extraction or forceps extraction if the cervix is fully dilated (2) knee-chest position (3) constant monitoring of fetal heart tones (4) immediate cesarean section if delivery is not imminent A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

E. Prolapse of the umbilical cord is a true obstetric emergency. Steps should include all of the options. This can occur without warning, and one must always be prepared for such an emergency.

The newborn infant (1) has a respiratory acidosis (2) has a high PCO2 (3) is hypoxic (4) has a metabolic acidosis A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

E. The newborn infant is prone to respiratory problems, since he or she has acidosis on both metabolic and respiratory bases and is hypoxic.

Which statement is correct regarding epidural blood patches? A. The success rate is approximately 50%. B. The presence of backache after the procedure implies improper technique. C. The incidence of infection following the procedure is approximately 2%. D. Epidural saline injection has the same success rate as an epidural blood patch. E. If the site of dural rent is uncertain, the lowermost interspace should be used.

E. The success rate of epidural blood patching is over 90% and the infection rate is less than 0.01% if sterile techniques are used. The use of saline is much less successful but incidence of backache is not unusual after blood patching. Because the spread of solution is usually greater in a cephalad direction, the lowermost interspace should be chosen if the site of dural puncture is uncertain.

Fetal effects of drugs administered to the mother may be modified by (1) blood flow from the umbilical vein passing through the ductus venosus (2) drug uptake by the fetal liver (3) dilution of blood in the right atrium (4) shunting across the foramen ovale A. if only 1, 2, and 3 are correct B. if only 1 and 3 are correct C. if only 2 and 4 are correct D. if only 4 is correct E. if all are correct

E. These factors all protect the fetus from receiving the full effect of drugs administered to the mother. The blood is diverted or diluted at several loci, decreasing the drug concentration in the brain of the fetus.

Parturients who have been on terbutaline to halt preterm labor may exhibit all of the following except A. cardiac arrhythmias B. pulmonary edema C. tachycardia D. hypotension E. hypoglycemia

E. Tocolytic agents, such as ritodrine and terbutaline, relax uterine smooth muscle by direct stimulation of beta-adrenergic receptors. These patients are at increased risk for fluid overload, tachycardia, dysrhythmia, hyperglycemia, decreased BP, and pulmonary edema. The etiology of pulmonary edema is controversial and has been reported to be both cardiac and noncardiac in origin.