Which of the following changes in pulmonary function best explains the more rapid rate of rise of alveolar concentration of volatile anesthetics in pregnant women than in nonpregnant women?
An asymptomatic 38-year-old woman is scheduled for elective cesarean delivery. The preoperative EKG shows left axis deviation that was not present one year ago. The most appropriate next step is to
(A) postpone the procedure and consult a cardiologist
(B) postpone the procedure and obtain an echocardiogram
(C) proceed with the procedure after administration of digitalis
(D) proceed with the procedure but avoid inhalational agents
(E) proceed without intervention since this is a normal finding
A woman has weakness of the right quadriceps and a decreased knee jerk reflex on the right one day after forceps delivery under epidural anesthesia. The most likely cause is
(A) epidural hematoma
(B) intrapelvic nerve trauma
(C) lithotomy positioning
(D) reaction to the preservative in the anesthetic solution
A multigravid woman is receiving oxytocin by infusion for augmentation of labor. Fetal heart rate is 190 bpm with beat-to-beat variability of 6 to 8 bpm. The most appropriate immediate action would be to
(A) continue observation
(B) sample fetal scalp blood
(C) discontinue oxytocics
(D) administer a beta-adrenergic blocker to the mother
Administration of succinylcholine 1 mg/kg to a pregnant woman rarely causes fetal neuromuscular blockade. Which characteristic of succinylcholine best explains this phenomenon?
Recognized side effects of magnesium sulfate used for the treatment of preeclampsia that would be of anesthetic concern include each of the following EXCEPT
(A) maternal pulmonary edema
(B) neonatal hypotonia
(C) increased maternal sensitivity to succinylcholine
Which of the following is most likely to result in oxygen desaturation in a patient with Eisenmenger's syndrome who is scheduled for cesarean delivery?
During active labor, 10 ml of bupivacaine 0.5% with epinephrine 1:200,000 is administered epidurally. Fifteen minutes later, maternal blood pressure is 70/50 mmHg and heart rate is 70 bpm; fetal heart rate is 90 bpm for 45 seconds, with loss of beat-to-beat variability. The most likely explanation for the fetal vital signs is
A woman at 39 weeks' gestation has been in labor for 12 hours. She has had nausea and vomiting for the past eight hours. Maternal arterial blood gas values are PaO1 85 mmHg, PaCO2 31 mmHg, and pH 7.50. Which of the following is the most likely cause of fetal distress occurring at this time?
(A) Hypocarbia-induced placental ischemia
(B) Impaired fetal oxyhemoglobin dissociation
(C) Shift to the left of the maternal oxyhemoglobin dissociation curve
Which of the following would be most likely to result in neonatal depression when administered to a healthy parturient during an uncomplicated labor and vaginal delivery?
(A) Nitrous oxide 60% in oxygen supplemented with halothane 0.5% for 10 minutes before delivery
(B) Ketamine 20 mg intravenously 30 minutes before delivery
(C) Meperidine 100 mg intramuscularly 2 hours before delivery
(D) Thiopental 100 mg intravenously 30 minutes before delivery
(E) Nitrous oxide 60% in oxygen supplemented with enflurane 0.7% for 10 minutes before delivery
A 30-year-old woman underwent emergency cesarean delivery under general anesthesia at 36 weeks' gestation because of preeclampsia. Two hours after the operation, she is still intubated and apneic and cannot be aroused. Deep tendon reflexes are 1+. With mechanical ventilation at an FiO2 of 0.4, PaO2 is 130 mmHg, PaCO2 is 32 mmHg, pH is 7.45, and base excess is -0.6. The most likely cause is
A 19-year-old woman receives a spinal anesthetic for a repeat cesarean delivery. Two days later she is afebrile but has severe occipital pain that is aggravated by sitting or standing and relieved by lying flat. Associated findings would likely include
A 25-year-old woman is undergoing emergency appendectomy at 36 weeks' gestation. Following subarachnoid injection of hyperbaric bupivacaine and placement in the supine position, the patient has nausea; heart rate is 105 bpm and blood pressure is 90/60 mmHg. Which of the following is the most appropriate management?
(A) Displacement of the uterus to the left
(B) Immediate tracheal intubation
(C) Intramuscular administration of ephedrine
(D) Placement of the operating table in the reverse Trendelenburg position
Fetal distress is noted after administration of an epidural local anesthetic during labor. Fetal scalp pH is 7.0. Compared with a fetus with a scalp pH of 7.3, in this fetus the local anesthetic is present in
(A) a higher concentration, with a larger fraction in the ionized form
(B) a higher concentration, with a larger fraction in the unionized form
(C) the same concentration, with a larger fraction in the ionized form
(D) the same concentration, with a larger fraction in the unionized form
(E) a lower concentration, with a larger fraction in the ionized form
A 28-year-old woman receives a lumbar epidural anesthetic for uncomplicated labor and delivery. During removal of the catheter, 1 cm breaks off and remains in her back. After informing the patient, the most appropriate management is
A woman is undergoing a repeat cesarean delivery at term following a normal pregnancy. Anesthesia consists of thiopental 250 mg, succinylcholine infusion (180 mg in 20 minutes), nitrous oxide and oxygen (7:3 L/min) until delivery. Twenty minutes after the incision a floppy newborn with a 1-minute Apgar score of 5 is delivered. The most likely explanation for the infant's condition is
A woman is in labor at 40 weeks' gestation and the fetus is in breech presentation. Which of the following will provide adequate uterine relaxation for vaginal delivery?
A 26-year-old woman has headache, nausea, and photophobia 36 hours after cesarean delivery for chorioamnionitis using subarachnoid block. Temperature is 38.8°C and leukocyte count is 14,200/mm3. Which of the following is the most appropriate next step in management?
Following maternal epidural injection, fetal exposure to chloroprocaine is lower than fetal exposure to bupivacaine for which of the following reasons?
(A) Chloroprocaine is metabolized by plasma cholinesterase
(B) Chloroprocaine is more protein bound
(C) Chloroprocaine is not readily absorbed from the epidural space
(D) The ionized fraction of chloroprocaine in the fetal circulation is smaller
(E) The pKa of chloroprocaine is less than that of bupivacaine
A parturient received 1000 ml of dextrose 5% in lactated Ringer's solution 20 minutes prior to delivery. Ten minutes later her blood glucose concentration is 580 mg/dl. In this situation
(A) the risk for fetal intraventricular hemorrhage is increased
(B) the risk for neonatal hypoglycemia is increased
(C) placental glucose transport is insulin dependent
(D) the neonate should be given dextrose 50% in water if depressed at delivery
(E) the mother should be given insulin prior to delivery
A parturient receives ketamine 2 mg/kg and succinylcholine 1.5 mg/kg for induction prior to elective cesarean delivery. Which of the following is most likely to be present in the newborn infant?
A 30-year-old primiparous woman delivered a healthy infant by cesarean section during uneventful spinal anesthesia with tetracaine 10 mg in 2 ml of 5% dextrose solution. Twelve hours after delivery she has bilateral loss of pain and temperature sensibility, but not touch, below T8 and paralysis of both legs. The most likely cause of this complication is
At the time of cesarean delivery, thick dark meconium is noted and the newborn is flaccid, apneic, bradycardic, and cyanotic. The most appropriate initial action is
Arterial oxyhemoglobin desaturation develops more rapidly following apnea in a pregnant patient at term than in a nonpregnant patient with a large intra-abdominal tumor. Which of the following findings in pregnancy is the most likely cause?
A 25-year-old woman is admitted to the hospital in the early stages of labor at term. Initial hematocrit is 33%. Which of the following is the most likely cause of the hematocrit value?
A 33-year-old primigravid woman with myasthenia gravis, well-controlled with pyridostigmine, is in labor with the cervix dilated 7 cm. She has a headache and feels very nervous. Blood pressure is 160/115 mmHg, she has 3+ pitting edema, and urinalysis shows 4+ protein. Appropriate management of her labor should include
(A) lumbar epidural block with bupivacaine 8 ml of 0.5% solution