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Flashcards in OB/Peds Deck (100):
1

In the United States, the leading cause of maternal death associated with a live birth is:

-pregnancy-induced hypertension
-pulmonary embolus
-cardiomyopathy
-hemorrhage

pulmonary embolus

2

On a per kilogram basis, ventilatory parameters that remain unchanged from birth through adulthood include:

-dead space
-minute ventilation
-functional residual capacity
-closing capacity

Tidal volume and dead space per kilogram remain constant during development.

3

Well-oxygenated fetal blood from the placenta has a PaO2 of approximately:

40 mmHg
60 mmHg
80 mmHg
100 mmHg

During a normal pregnancy, umbilical vein blood has a PaO2 of approximately 40 mmHg

4

A preterm (33 week gestation) neonate is delivered emergently by cesarean section. The baby shows tachypnea, grunting, intercostal retractions and is cyanotic. The most likely cause of the cyanosis is:

insufficient surfactant production
transposition of the great vessels
insufficient hemoglobin F production
tetralogy of Fallot

insufficient surfactant production: The most common cause of respiratory distress in preterm neonates is the respiratory distress syndrome (RDS) also known as hyaline membrane disease. The syndrome is responsible for 50 - 75% of deaths in preterm neonates. It is the result of deficient production and secretion of surfactant, which is produced by type II pneumocytes. Mature levels of surfactant are not present until 35 weeks of gestation.

5

Electrocardiographic changes associated with the third trimester of pregnancy include:

right axis deviation
first degree AV block
left axis deviation
sinus bradycardia

left axis deviation: Elevation of the diaphragm shifts the heart position in the chest resulting in the appearance of an enlarged heart on a plain chest film and in left axis deviation and T wave changes on the electrocardiogram.

6

After delivery of a 4.0 kg neonate recurrent bradycardia is noted. An umbilical artery catheter is placed at which time the neonate becomes asystolic. An appropriate dose of epinephrine would be:

0.01 mg
0.25 mg
0.04 mg
0.50 mg

0.04 mg: Epinephrine 0.01 - 0.03 mg/kg is indicated for neonatal bradycardia (

7

The most common morbidity encountered in obstetrics is:

severe sepsis
severe preeclampsia
HELLP syndrome
severe hemorrhage

severe hemorrhage: The most common morbidities encountered in obstetrics are severe hemorrhage (6.9/1000) and severe preeclampsia (3.9/1000).

8

A 9-year-old patient with a history of cerebral palsy is scheduled for release of contractures of the Achilles tendons. The patient is receiving phenytoin for control of seizures. Anesthetic considerations in this patient include:

-an increased sensitivity to nondepolarizing blockers
-the likelihood of gastroesophageal reflux disease
-the possibility of severe hyperkalemia with the use of succinylcholine
-the avoidance of volatile anesthetics because of an increased incidence of MH in these patients

Management of anesthesia in children with cerebral palsy includes tracheal intubation because of the propensity for GERD and poor function of laryngeal and pharyngeal reflexes. There is no increase in the incidence of MH in these patients and the use of volatile anesthetics has been shown to be safe. Patients receiving anticonvulsants may be more resistant to the effects of nondepolarizing relaxants. Despite the skeletal muscle spasticity, succinylcholine does not produce abnormal potassium release in these patients.

9

You are asked to evaluate 31-year-old G3P2 woman for a repeat cesarean section. Her past medical history is significant for 2 previous cesarean sections. She has been laboring for the previous 7 hours with little progress despite an oxytocin infusion. During the interview, the patient complains of sudden severe continuous abdominal pain radiating to her left shoulder. These symptoms are most consistent with:

preeclampsia
abruptio placentae
uterine rupture
placenta previa

Uterine rupture is often heralded by severe abdominal pain, referred to the shoulder due to subdiaphragmatic irritation by intra-abdominal blood. Uterine rupture is associated previous uterine scars and excessive oxytocin stimulation. Current recommendations discourage VBAC in women with two or more previous uterine incisions.

10

As compared to regional anesthesia, the risk of maternal death from general anesthesia is approximately:

the same
three times greater
eight times greater
sixteen times greater

sixteen times greater: Based on data collected between 1985 and 1990, maternal mortality from general anesthesia is approximately 32 per 1,000,000 live births. In comparison, mortality from regional anesthesia is only 1.9 per 1,000,000 live births.

11

In the fetus, blood entering the right atrium from the inferior vena cava is preferentially directed to the:

ductus arteriosus
right ventricle
foramen ovale
ductus venosus

foramen ovale: Right atrial anatomy preferentially directs blood from the inferior vena cava through the foramen ovale into the left atrium.

12

Functional residual capacity is decreased in the neonate as a result of:

increased lung compliance and decreased chest wall compliance
decreased lung compliance and increased chest wall compliance
increased lung compliance and increased chest wall compliance
decreased lung compliance and decreased chest wall compliance

decreased lung compliance and increased chest wall compliance: The small and limited number of alveoli in neonates and infants reduces lung compliance; in contrast, their cartilaginous rib cage makes their chest wall very compliant. The combination of these two characteristics promotes chest wall collapse during inspiration and relatively low residual lung volumes at expiration.

13

Of the following, the lowest degree of placental drug transfer occurs with the use of:

bupivacaine
chloroprocaine
lidocaine
ropivacaine

chloroprocaine: Chloroprocaine has the least placental transfer because it is rapidly broken down by plasma cholinesterase in the maternal circulation.

14

Post-intubation laryngotracheobronchitis (croup) is most commonly seen in children of:

0 - 1 year of age
1 - 4 years of age
4 - 7 years of age
7 - 9 years of age

1 - 4 years of age: Post-intubation croup is due to glottic or tracheal edema and is associated with early childhood (ages 1 - 4), repeated intubation attempts, large endotracheal tubes, prolonged surgery, head and neck procedures and excessive movement of the endotracheal tube. Nebulized racemic epinephrine is an effective treatment

15

Renal changes seen during pregnancy include a reduction in:

plasma levels of renin and aldosterone
the tubular threshold for glucose and amino acids
glomerular filtration
renal plasma flow

the tubular threshold for glucose and amino acids: Renal vasodilation increases renal blood flow, glomerular filtration and renal plasma flow. Increased renin and aldosterone levels promote sodium retention. A decreased renal tubular threshold for glucose and amino acids is common and often results in mild glycosuria or proteinuria.

16

The appropriate endotracheal tube diameter for a full-term neonate is approximately:

2.0 mm
3.0 mm
4.0 mm
4.5 mm

3.0 mm: For pediatric patients, the appropriate diameter of the endotracheal tube can be estimated by the formula: Tube diameter = 4 + (age/4)Exceptions include premature neonates (2.5 - 3.0 mm) and full-term neonates (3.0 - 3.5 mm).

17

Pain during the latent phase of labor is usually confined to dermatomes:

T11 - T12
L1 - L2
L3 - L4
L5 - S1

T11 - T12: Pain during the first stage of labor is mostly visceral pain resulting from uterine contractions and cervical dilatation. It is usually initially confined to the T11 - T12 dermatomes during the latent phase, but eventually involves the T1- - L1 dermatomes as the labor enters the active phase.

18

A 12-year-old patient is scheduled for an excision of a sellar craniopharyngioma. Suspected preoperative laboratory abnormalities in this patient include:

a decreased thyroxine (T4) level with an elevated thyrotropin level
an elevated plasma cortisol level
hypernatremia
an elevated growth hormone level

hypernatremia: Craniopharyngioma is the most common intracranial tumor of nonglial origin in the pediatric population. Because the tumor can affect the pituitary, endocrine dysfunction is common. Secondary hypothyroidism, growth hormone deficiency, secondary hypocortisolism and diabetes insipidus should all be suspected. Diabetes insipidus can present preoperatively as hypernatremia, but may also be seen 4 - 6 hours postoperatively, due to surgical damage to the pituitary.

19

A 34-year-old patient presents to the emergency room in labor with contractions occurring every 4 minutes. She is at 32 weeks of gestation. Pharmacologic inhibition of uterine contractions can be accomplished with:

intravenous calcium chloride therapy
intravenous betamethasone therapy
intravenous metoprolol therapy
intravenous ritodrine therapy

intravenous ritodrine therapy: The most commonly used tocolytics are β2-agonists (ritodrine or terbutaline) and magnesium. Although betamethasone may be given to induce fetal production of surfactant, it is not effective as a tocolytic agent. More recently, oxytocin antagonist, atosiban, has show effectiveness in patients of greater than 28 weeks gestation

20

At 20 weeks' gestation, frequently found changes in heart sounds include:

loss of split of the first heart sound
grade I to II diastolic murmur
presence of a third heart sound
all of the above

presence of a third heart sound: Several changes in heart sounds occur during pregnancy. Early closure of the mitral valve may cause a split first heart sound. A third heart sound can be heard in most women by 20 weeks' gestation. A benign grade I or II systolic murmur is also common. Diastolic murmurs are pathologic.

21

As compared to the non-pregnant patient, the incidence of pulmonary aspiration of gastric contents in the obstetric patient is:

approximately equal if cricoid pressure is applied
twice as great
4 - 5 times greater
8 - 10 times greater

4 - 5 times greater: Pulmonary aspiration of gastric contents is 4 - 5 times greater in the obstetric patient with an incidence of 1:400 - 500 as compared to an incidence of 1:2000 in the non-pregnant patient.

22

The position of the larynx in the neonate is at approximately:

C2
C4
C6
C8

C4: Neonates and infants have a proportionately larger head and tongue, narrow nasal passages, an anterior and cephalad larynx (at vertebral level C4 versus C6 in adults), a long epiglottis and a short trachea

23

Clinically significant placental drug transfer has NOT been shown to occur with the use of:

ephedrine
labetelol
glycopyrrolate
metoclopramide

glycopyrrolate: Most commonly used anesthetic adjuncts readily cross the placenta. Maternally administered ephedrine, labetalol, esmolol, vasodilators, phenothiazines, antihistamines, metoclopramide, atropine and scopolamine cross the placenta in clinically signifcant amounts. Glycopyrrolate administration, as a result of the drug's quaternary ammonium structure, results in only limited placental transfer.

24

A 38-postconception week neonate is scheduled for an emergent repair of an incarcerated inguinal hernia. The patient was delivered at 34 weeks of gestation. Anesthetic management of this patient should include:

maintenance of the arterial PaO2 above 100 mmHg
permissive hypercapnea to reduce barotrauma to the lungs
maintenance of oxygen saturation between 89 - 94%
the use of 3% NaCl for fluid replacement

maintenance of oxygen saturation between 89 - 94%: In this preterm neonate there exists a substantial risk for the development of retinopathy of prematurity. Because the optimal intraoperative oxygen saturation for these infants is not known, it is prudent to limit oxygen supplementation during the period of retinal vascularization (up to 44 weeks postconception). Efforts should be made to maintain PaO2 between 50 - 80 mmHg and PaCO2 between 35 - 45 mmHg. This results in a pulse oximetry target of 89 - 94%.

25

Pulmonary aspiration during the induction of general anesthesia in the pregnant patient is more likely as a result of:

the posterior displacement of the stomach by the uterus
placental gastrin secretion
increased intragastric pressure
progesterone-induced increase in lower esophageal sphincter tone

placental gastrin secretion: Upward and anterior displacement of the stomach by the uterus promotes incompetence of the GE sphincter. Elevated progesterone levels reduce the tone of the GE sphincter. Placental gastrin secretion causes hypersecretion of gastric acid. Intragastric pressure is unchanged during pregnancy.

26

A 10-kg child is scheduled for a resection of a skin lesion of the right thigh. The anesthetic plan calls for the use of a laryngeal mask airway. The appropriate size of the LMA for this patient is:

1
2
3
4

2
Size Age Weight Cuff Vol
1 Infant 30 kg up to 20
4 Adult 70 kg up to 30

27

Morphine is infrequently used as an analgesic during labor because at equianalgesic doses it appears to cause:

a higher incidence of fetal seizures as compared to fentanyl
a higher incidence of fetal respiratory depression as compared to fentanyl
a greater loss of fetal thermal regulation as compared to fentanyl
a higher incidence of fetal bronchospasm as compared to fentanyl

a higher incidence of fetal respiratory depression as compared to fentanyl: Morphine is seldom used for maternal analgesia because in equianalgesic doses it appears to cause greater respiratory depression in the fetus than meperidine or fentanyl.

28

Factors complicating the airway management in the patient with trisomy 21 include:

microglossia
prognathia
hypertonicity of the masseter muscles
occipitoatlantoaxial instability

occipitoatlantoaxial instability: Trisomy 21 or Down syndrome is the most common human chromosomal syndrome. Airway management in these patients can be difficult due to macroglossia, micrognathia, narrow hypopharynx and muscular hypotonia. There is also a risk of spinal cord compression due to occipitoatlantoaxial instability.

29

Pathophysiologic events associated with preeclampsia include:

an production imbalance between prostacyclin and thromboxane A2
intravascular volume expansion
decreased vascular sensitivity to catecholamines
thrombocytosis

an production imbalance between prostacyclin and thromboxane A2: Pregnancy-induced hypertension (PIH) encompasses a range of disorders, including gestational hypertension, preeclampsia and eclampsia. Three principal mechanisms serve as the etiology of PIH. These mechanisms are: abnormal sensitivity of vascular smooth muscle to catecholamines, placental vasculitis, and an imbalance in the production of vasoactive prostaglandins (thromboxane A2 and prostacyclin).

30

At term, maternal plasma volume has:

decreased by approximately 15%
increased by approximately 15%
increased by approximately 25%
increased by approximately 50%

increased by approximately 50%: Maternal blood volume increases to between 85 and 100 ml/kg at term. Increases occur in both plasma volume (50%) and blood cell mass (up to 20%). Because the increase in plasma volume is greater, a relative dilutional anemia occurs.

31

Treatment of cardiac toxicity secondary to unintentional intravascular bupivacaine injection should include:

control of arrhythmias with intravenous lidocaine
control of arrhythmias with intravenous verapamil
avoidance of cardioversion
the administration of a 20% lipid solution

the administration of a 20% lipid solution: Cardiac toxicity from bupivacaine may be difficult to treat. Hyperventilation with oxygen should be immediately instituted. Ventricular dysrhythmias may need large and multiple doses of electrical cardioversion, epinephrine, vasopressin and amiodarone. The use of calcium channel blockers is not recommended. The administration of a 20% lipid solution at an initial dose of 4 mL/kg has been found to improve survival.

32

In children under 5 years of age, the narrowest point of the airway is the:

rima glottis
thyroid cartilage
cricoid cartilage
hyoid cartilage

cricoid cartilage: The cricoid cartilage is the narrowest point of the airway in children younger than 5 years of age; in the adult, the narrowest point is the glottis.

33

In the parturient, uterine hypertonus has been associated with the use of large induction doses of:

thiopental
propofol
etomidate
ketamine

ketamine: Uterine hypertonus may occur with ketamine at doses > 2 mg/kg.

34

Kernicterus has been reported after the intravenous administration of drugs to neonates which contain the preservative:

metabisulfite
p-amino benzoic acid
EDTA
benzyl alcohol

benzyl alcohol: Benzyl alcohol has been implicated in causing kernicterus by displacing bilirubin from albumin and facilitating its entry into the brain. Certain preparations of propofol and normal saline flush can contain benzyl alcohol and should be avoided in the neonate.

35

At term, pseudocholinesterase activity is:

increased by 10%
increased by 30%
decreased by 10%
decreased by 30%

decreased by 30%: A 25 - 30% decrease in serum pseudocholinesterase activity is present at term, but rarely produces significant prolongation in the action of succinylcholine.

36

A 12-kg child is scheduled for repair of an inguinal hernia. The patient had an upper respiratory infection 2 weeks ago, but now has full resolution of symptoms. At this time, this patient is at increased perioperative risk for:

bronchospasm
laryngospasm
hypoxemia

all of the above all of the above: A viral infection within 2 - 4 weeks before general anesthesia and endotracheal intubation appears to place the child at risk for perioperative pulmonary complications such as bronchospasm (10 fold), laryngospasm (5 fold), hypoxia and atelectasis.

37

Nonsteroidal antiinflammatory agents, such as ketorloac, are not recommended as analgesics during labor because they are associated with:

delayed closure of the ductus arteriosus
maternal and fetal respiratory depression
suppression of uterine contractions
impaired placental oxygen transfer to the fetus

suppression of uterine contractions: Nonsteroidal antiinflammatory agents are not recommended because they suppress uterine contractions and promote closure of the fetal ductus arteriosus.

38

Treacher-Collins syndrome:

results in anterior displacement of the tongue
results in mandibular hyperplasia
is often associated with other craniofacial abnormalities such as cleft palate
follows an autosomal recessive inheritance pattern

is often associated with other craniofacial abnormalities such as cleft palate: Treacher-Collins syndrome is the most common of the mandibulofacial dysostoses. Inheritance is as an autosomal dominant trait. Hypoplasia of the mandible with posterior displacement of the tongue (glossoptosis) can result in early airway problems. Treacher-Collins syndrome is associated with cleft palate, ventricular septal defect, and gross deformites of the external ear canals and ossicular chain. These patients present extreme difficulty with airway management and facilities for surgical airway placement should be part of the anesthetic plan.

39

In the patient with pregnancy-induced hypertension, epidural analgesia during labor has been associated with:

increased maternal catecholamine levels
improved uteroplacental blood flow
increased uterine artery vasospasm
fetal distress

. improved uteroplacental blood flow: Epidural analgesia is the preferred technique for labor analgesia in the patient with PIH if not contraindicated by coagulopathy. Epidural analgesia reduces maternal catecholamine levels and facilitates blood pressure control. Epidural analgesia improves intervillous blood flow thus improving uteroplacental performance and fetal well-being.

40

At term, maternal red cell mass has:

decreased by up to 15%
increased by up to 10%
increased by up to 20%
increased by up to 50%

increased by up to 20%: Maternal blood volume increases to between 85 and 100 ml/kg at term. Increases occur in both plasma volume (50%) and red blood cell mass (up to 20%). Because the increase in plasma volume is greater, a relative dilutional anemia occurs.

41

You are asked to evaluate a 28-year-old female complaining of a headache following an uneventful vaginal delivery with continuous epidural analgesia. Likely causes for the headache include:

the injection of significant amounts of air during epidural placement
the placement of a multiholed epidural catheter
the use of 0.25% bupivacaine for the initial injection
the use of fentanyl in the epidural infusion

the injection of significant amounts of air during epidural placement: Headache frequently follows unintentional subdural puncture in parturients. However, a self-limited headache may occur without dural puncture; in such instances, injection of significant amounts of air into the epidural space may be responsible.

42

In neonates and infants, variations in cardiac output are largely the result of changes in:

systemic vascular resistance
stroke volume
baroreceptor reflexes
heart rate

heart rate: Stroke volume is relatively fixed by a noncompliant and poorly developed left ventricle in neonates and infants. The cardiac output is therefore very dependent on heart rate. Additionally, sympathetic nervous system and baroreceptor reflexes are not fully mature and less able to compensate for changes in blood pressure.

43

The beginning of the second stage of labor is defined by:

the presence of full cervical dilatation
the presence of the active phase of labor
the rupture of the amniotic sac
the presence of uterine contractions occurring at a frequency > 2 mins

the presence of full cervical dilatation: The second stage begins with full cervical dilatation, is characterized by fetal descent, and ends with complete delivery of the fetus.

44

The most common metabolic abnormality in the neonate is:

hypoglycemia
hyponatremia
hypokalemia
hypocalcemia

hypoglycemia: Hypoglycemia is the most common metabolic problem occurring in the neonate. Inadequate glycogen stores and deficient gluconeogenesis are important factors in the newborn's susceptibility to hypoglycemia. The incidence is highest in small-for-gestational age neonates and in neonates of diabetic mothers.

45

During pregnancy, the level of which of the following clotting factors may be decreased?

VII
VIII
XI
XII

XI: Pregnancy is associated with a hypercoagulable state. Fibrinogen and factors VII, VIII, IX, X and XII concentrations all increase; only factor XI may decrease.

46

An 8-kg infant is to receive general anesthesia with endotracheal intubation. Current recommendations concerning the preoperative fasting of this patient include:

the patient should be NPO for 6 - 8 hours prior to surgery
clear fluids can be given up to 1 hour prior to surgery
breast milk may be given up to 4 hours prior to surgery
solid foods may be given up to 3 hours prior to surgery

breast milk may be given up to 4 hours prior to surgery:Current fasting recommendations for children include: Solids are prohibited within 6 - 8 hours of surgery, formula within 6 hours, breast milk within 4 hours and clear liquids within 2 hours of surgery.

47

Pain relief during the second stage of labor requires neural blockade from T10 to:

S1
S2
S3
S4

S4: Sensory innervation of the perineum is provided by the pudendal nerve (S2 - S4) so pain during the second stage of labor involves the T10 - S4 dermatomes

48

An increased incidence of malignant hyperthermia is seen in children with:

central core disease
Duchenne's muscular dystrophy
malignant neuroleptic syndrome
cerebral palsy

central core disease: Linkage of MH with other diseases has been problematic: only central core disease appears to be truly linked. In Duchenne's muscular dystrophy, the balance of opinion has shifted from an association with MH to an anesthesia-induced rhabdomyolysis. Cerebral palsy and malignant neuroleptic syndrome are not associated with an increased incidence of MH, although malignant neuroleptic syndrome may mimic MH and is part of the differential diagnosis.

49

Maternal mortality associated with amniotic fluid embolism is:

10 - 20%
25 - 40%
50 - 75%
> 80% .

> 80%: Even with immediate and aggressive treatment, mortality due to amniotic fluid embolism remains higher than 80%.

50

At term, commonly found changes in maternal blood pressure include:

little change in systolic pressure with decreased diastolic pressure
increased systolic pressure with decreased diastolic pressure
decreased systolic and diastolic pressures
increased systolic and diastolic pressures

little change in systolic pressure with decreased diastolic pressure: Overall, at term, systolic blood pressure changes little. A decrease in diastolic blood pressure of 15 mmHg may occur resulting in a decrease in mean pressure and an increase in pulse pressure.

51

You are called to deliver anesthesia for an emergent cesarean section in a 28-year-old, 100-kg female with umbilical cord prolapse. After intravenous induction, several attempts at endotracheal intubation are unsuccessful. The most appropriate management at this time should include:

transtracheal jet ventilation
placement of an LMA while maintaining cricoid pressure
awakening of the patient and placement of an epidural anesthetic
obtaining a surgical airway

placement of an LMA while maintaining cricoid pressure: In the face of severe fetal distress, general anesthesia is indicated. If initial attempts at intubation fail, ventilation should be attempted with either the face mask or LMA, while continuing cricoid pressure.

52

Intraoperative heat loss is greater in neonates versus adults as a result of:

a larger surface to core ratio in the neonate
increased skin thickness in the neonate
increased subcutaneous adipose tissue in the neonate
an increases shivering response in the neonate

a larger surface to core ratio in the neonate: Pediatric patients have a larger surface area per kilogram than adults. Thinner skin and a lower fat content also contribute to greater heat loss in the neonate. Shivering is not an important method of thermogenesis in the neonate.

53

The greatest strain on the maternal heart occurs:

during the active phase of labor
immediately after delivery
during the latent phase of labor
during the second stage of labor

immediately after delivery: The greatest strain on the heart occurs immediately after deilvery, when intense uterine contraction and involution suddenly relieve inferior vena caval obstruction and increse cardiac output as much as 80% above prelabor values.

54

Upon delivery of a 3.2 kg male, the neonate is noted be cyanotic, with a scaphoid abdomen. Auscultation of the chest reveals bowel sounds in the left hemithorax. Management of this infant should include:

decompression of the stomach with a orogastric tube
positive pressure ventilation by mask with 100% oxygen
awake intubation and ventilation with 100% oxygen and increased inspiratory pressures to inflate the left lung
all of the above

decompression of the stomach with a orogastric tube: This neonate's signs and symptoms are consistent with congenital diaphragmatic hernia. Immediate treatment should include decompression of the stomach and the administration of supplemental oxygen. Positive pressure by mask should be avoided as it may cause stomach distention and further compromise pulmonary function. Awake intubation should be performed, but positive airway pressures should not exceed 25 - 30 mmHg as it can precipitate damage to the normal lung and pneumothorax.

55

During pregnancy, the level of which of the following hormones steadily increases?

Free T4
Insulin
TSH
Free T3

insulin: Pregnancy is a diabetogenic state; insulin levels steadily rise during pregnancy. Although it is common for the thyroid gland to become hypertrophied during pregnancy, levels of free T4, free T3 and TSH remain normal.

56

In children with right-to-left intracardiac shunting, inhalation induction is expected to be:

slower than in healthy children
faster than in healthy children
unaffected by the presence of the shunt
faster than in healthy children when very soluble agents are used

slower than in healthy children: A right-to-left shunt slows the inhaled induction of anesthesia because anesthetic concentration in the arterial blood increases more slowly. A left-to-right shunt has little effect since the decreased delivery of anesthetic to the target tissues negates the increased uptake with this type of shunt.

57

The administration of a β2 stimulant to the laboring parturient will cause:

an increase in uterine tone
a decrease in uterine tone
a decrease in placental blood flow
an acceleration to the second stage of labor

a decrease in uterine tone: Uterine muscle has both α- and β-receptors. α1-Receptor stimulation causes uterine contraction, whereas β2-receptor stimulation produces relaxation..

58

The most common congenital cardiac abnormality in infants and children is:

atrial septal defect
ventricular septal defect
patent ductus arteriosus
tetralogy of Fallot

ventricular septal defect: Ventricular septal defect is the most common congenital cardiac abnormality, constituting approximately 35% of all congenital cardiac abnormalities.

59

A 26-year-old female with a history of mitral stenosis is in labor. Beneficial effects of epidural analgesia in this patient include:

a mild increase in pulmonary vascular resistance
a mild decrease in preload
reduced incidence of pain-induced maternal tachycardia
all of the above

reduced incidence of pain-induced maternal tachycardia: Mitral stenosis is the most common type of cardiac valvular defect seen in pregnant patients. Epidural analgesia during labor and delivery reduce pain-induced tachycardia allowing more time for left ventricular filling. Preload should be maintained and causes of pulmonary vasoconstriction (hypoxia) should be avoided

60

At term, the MAC of inhaled anesthetic agents is:

increased by approximately 20%
increased by approximately 40%
decreased by approximately 20%
decreased by approximately 40%

decreased by approximately 40%: The MAC progressively decreases during pregnancy - at term by as much as 40% - for all general anesthetic agents. MAC returns to normal by the third day after delivery.

61

Breech presentations:

have little effect on fetal morbidity if vaginal delivery is accomplished
are commonly seen with the post-mature fetus
are associated with an increased incidence of cord prolapse
complicate about 10% of pregnancies

are associated with an increased incidence of cord prolapsed: Breech presentations complicate 3 - 4% of deliveries and significantly increase both maternal and fetal morbidity and mortality rates. The most common cause is prematurity. Breech presentation also increases the incidence of cord prolapse to 10%.

62

A 3.2-kg term neonate is scheduled for a pyloromyotomy. The estimated blood volume of this neonate is approximately:

154 mL
280 mL
332 mL
401 mL

280 mL: Full-term neonates have a blood volume of 85 - 90 mL/kg. In this neonate the EBV = 85 - 90 mL/kg x 3.2 kg = 272 - 288 mL.

63

Low dose (

cause little change in the effects of oxytocin on the uterus: Isoflurane, sevoflurane and desflurane depress uterine activity equally at equipotent doses. Low doses (

64

The most common form of tracheoesophageal fistula consists of:

a blind upper esophageal pouch with no fistula between the esophagus and trachea
a blind upper esophageal pouch with a fistula between the trachea and distal esophagus
a fistula between a blind upper esophageal pouch and the trachea
a fistula between the trachea and an otherwise normal esophagus

a blind upper esophageal pouch with a fistula between the trachea and distal esophagus: Approximately 86% of tracheoesophageal fistulas are of Type III B, consisting of a blind upper esophageal pouch and a tracheal fistula connecting to the distal esophagus. Anesthetic management ideally consists of an awake intubation with placement of the ETT distal to the fistula, but above the carina.

65

At term, uterine blood flow represents approximately:

5% of the cardiac output
10% of the cardiac output
20% of the cardiac output
30% of the cardiac output

10% of the cardiac output: There is an increase in cardiac output of approximately 40% at term and about 10% or 600 - 700 mL/min represents the uterine blood flow.

66

In order to maintain euglycemia, in the neonate, it is recommended that intravenous fluid therapy include glucose infused at a rate of:

3 - 5 mg/kg/hour
3 - 5 mg/kg/min
6 - 10 mg/kg/hour
6 - 10 mg/kg/min

3 - 5 mg/kg/min: Neonates require 3 - 5 mg/kg/min of glucose infusion to maintain euglycemia; premature neonates require 5 - 6 mg/kg/min.

67

In contrast to the single-hole epidural catheter, the multiholed catheter:

requires a shorter depth of insertion
is associated with a lower incidence of unilateral block
increases the incidence of false-negative aspiration for intravascular placement
all of the above

is associated with a lower incidence of unilateral block: Use of a multiholed catheter appears to be associated with fewer unilateral blocks and greatly reduces the incidence of false-negative aspiration for intravascular catheter placement. Advancing a multiholed catheter 7 - 8 cm into the epidural space appears to be optimal for obtaining adequate sensory levels.

68

Hypercyanotic attacks associated with the tetralogy of Fallot are best treated with:

epinephrine
isoproterenol
phenylephrine
nitroglycerine

phenylephrine: Treatment of hypercyanotic attacks is influenced by the cause of the pulmonary outflow obstruction. When symptoms reflect a dynamic infundibular obstruction, beta-blockers are appropriate treatment. If the cause is decreased systemic vascular resistance, treatment is intravenous fluids and/or phenylephrine. Sympathomimetic drugs with β-agonistic properties or vasodilators should not be used.

69

In the absence of drug administration, sustained decreased baseline variability in the fetal heart rate suggests:

normal progress from the latent to active phase of labor
normal progress from the first to second stage of labor
full development of the neural pathways of the vagus nerve
fetal distress

fetal distress: Fetal heart rate varies 5 to 20 bpm in the normal fetus. Fetal distress due to arterial hypoxemia, acidosis or CNS damage is associated with minimal to absent beat-to-beat variability.

70

Obstruction of the inferior vena cava by the enlarging uterus results in:

decreased blood volume in the epidural venous plexus
decreased spinal cerebrospinal fluid volume
increased potential volume of the epidural space
decreased epidural space pressure

decreased spinal cerebrospinal fluid volume: Obstruction of the inferior vena cava by the enlarging uterus distends the epidural venous plexus and increases epidural blood volume. The latter has three major effects: (1) decreased CSF volume, (2) decreased potential volume of the epidural space and (3) increased epidural space pressure.

71

The greatest risk factor for placenta previa is:

prematurity
polyhydramnios
nulliparity
previous cesarean section

previous cesarean section: The greatest risk factor for placenta previa is previous cesarean section. Other risk factors include previous uterine myomectomy, multiparity, advanced maternal age and a large placenta.

72

As compared to a 3-month-old infant, the minimum alveolar concentration of desflurane required to anesthetize a full-term neonate is approximately:

10% greater
25% greater
10% less
25% less

25% less: Full-term neonates require lower concentrations of volatile anesthetics than do infants 1 - 6 months of age. The MAC is about 25% less in neonates than in infants. Furthermore, MAC in preterm neonates is less than full-term neonates. MAC steadily increases until 2 - 3 months of age and then steadily declines with age.

73

During labor, continuous epidural analgesia with 0.1% bupivacaine with fentanyl 5 μg/mL has been associated with:

an increased rate of cesarean section
an increased rate of forceps delivery
decreased effectiveness of oxytocin
minimal or no change in the duration of labor

minimal or no change in the duration of labor: Current techniques employing dilute combinations of local anesthetic and opioid for epidural analgesia do not appear to prolong labor or increase the likelihood of cesarean section.

74

As compared to patients with gastroschisis, patients with omphalocele:

rarely have any other congenital defects
lack a peritoneal covering of the abdominal contents
have a midline defect at the base of the umbilical cord
are usually delivered after the 42nd gestational week

have a midline defect at the base of the umbilical cord: Omphalocele manifests as external herniation of abdominal viscera through the base of the umbilical cord. The abdominal contents are contained within a sac formed from the peritoneal membrane without overlying skin. Omphalocele is associated with a 75% incidence of other congenital defects. Approximately 33% of neonates with omphaloceles are preterm.

75

During pregnancy, uterine blood flow is directly proportional to:

the difference between uterine arterial and venous pressures
uterine vascular resistance
uterine venous pressure
degree of endogenous catecholamine release

the difference between uterine arterial and venous pressures: Uterine blood flow is directly proportional to the difference between uterine arterial and venous pressures, but inversely proportional to uterine vascular resistance. Stress-induced release of endogenous catecholamines can cause uterine vasoconstriction and reduce uterine blood flow.

76

Disadvantages of intranasally administered midazolam for the premedication of children include:

slower absorption as compared to oral administration
loss of drug to first-pass extraction
irritation of the nasal mucosa
increased dosage requirement as compared to oral administration

irritation of the nasal mucosa: A major disadvantage of intranasally administered midazolam is that most children cry upon administration because it transiently irritates the nasal passages. Rapid absorption and avoidance of first-pass hepatic metabolism are advantages of this route of administration. Midazolam can be administered intranasally at a dose of 0.2 mg/kg; oral dosing requires 0.5 - 0.75 mg/kg.

77

In the parturient, the most common complication of regional anesthesia is:

unintentional intravascular injection
unintentional intrathecal injection
hypotension
postdural puncture headache

hypotension: Hypotension is the most common complication of regional anesthesia. It is primarily due to decreased sympathetic tone and is greatly accentuated by aortocaval compression.

78

A 3-month-old is scheduled for correction of tetralogy of Fallot. Induction of anesthesia is best accomplished with:

thiopental
isoflurane
desflurane
ketamine

ketamine: Induction of anesthesia in patients with tetralogy of Fallot is often accomplished with intravenous or intramuscular ketamine. The onset of anesthesia after ketamine injection may be associated with improved oxygenation, presumably reflecting increased pulmonary blood flow due to ketamine-induced increases in systemic vascular resistance.

79

The fetal heart rate tracing below is:

suggestive of fetal distress
suggestive of fetal head compression
suggestive of fetal cord compression
a reassuring tracing



This tracing is indicative of late decelerations. Late decelerations are characterized by the slowing of the fetal heart rate that begins 10 - 30 seconds after the onset of uterine contractions. Late decelerations are associated with fetal distress.

80

During pregnancy, the P-50 of maternal hemoglobin:

increases to about 30 mmHg
increases to about 40 mmHg
remains unchanged
decreases to about 23 mmHg

increases to about 30 mmHg: During pregnancy, the P-50 for the maternal hemoglobin increases from 27 to 30 mmHg; the combination of this and increased cardiac output enhances oxygen delivery to tissues and placenta.

81

Placenta accreta:

is associated with massive hemorrhage from manual extraction of the placenta
is rarely seen in patients with placenta previa
involves invasion of the placenta into the myometrium
is not associated with previous cesarean section

is associated with massive hemorrhage from manual extraction of the placenta: Placenta accreta is an adherent placenta that has not invaded the myometrium. Massive hemorrhage may occur when removal of the placenta is attempted after delivery. Risk factors include placenta previa and previous cesarean delivery.

82

As compared to an adult, the alveolar uptake of inhalational anesthetics is greater in the neonate as a result of:

a greater minute ventilation to FRC ratio in the neonate
the smaller cardiac output of the neonate
increased blood solubility of the agent in the neonate
increased dead space to shunt ratio in the neonate

a greater minute ventilation to FRC ratio in the neonate: Uptake of inhaled anesthetics is more rapid in infants than in older children or adults. This accelerated uptake most likely reflects the infant's high alveolar ventilation relative to functional residual capacity.

83

Complications associated with oxytocin administration include:

maternal water intoxication
uterine atony
hypertension with rapid infusion
all of the above

maternal water intoxication: Complications of oxytocin administration include fetal distress due to hyperstimulation, uterine tetany and maternal water intoxication. Rapid intravenous infusion can also cause transient systemic hypotension due to relaxation of vascular smooth muscle.

84

Anesthetic care of the neonate undergoing correction of gastroschisis should include:

maintenance of adequate hydration with 4 mL/kg/hour of crystalloid solution
the use of nitrous oxide to hasten emergence and extubation
the avoidance of muscle relaxation
preoperative hydration with both crystalloid and colloid solutions

preoperative hydration with both crystalloid and colloid solutions: Preoperative fluid management will require 2 - 4 times the usual daily maintenance (8 - 16 mL/kg/hour) These neonates experience considerable protein loss. To maintain normal oncotic pressures, protein containing solutions should constitute approximately 25% of the replacement fluids. Repair of large defects will require maximal muscle relaxation both intraoperatively and postoperatively. Nitrous oxide is avoided because of its ability to diffuse into the intestinal tract making closure more difficult.

85

Vascular components of the umbilical cord include:

one umbilical artery and one umbilical vein
one umbilical artery and two umbilical veins
two umbilical arteries and one umbilical vein
two umbilical arteries and two umbilical veins

two umbilical arteries and one umbilical vein: Fetal blood flow within the placenta is derived from the umbilical cord via two umbilical arteries and returns to the fetus via a single umbilical vein.

86

Epiglottitis is:

effectively treated with nebulized racemic epinephrine
best managed with an awake intubation
most commonly secondary to viral infection of the trachea
associated with inflammation of all supraglottic structures

associated with inflammation of all supraglottic structures: Acute epiglottitis is a bacterial infection affecting all supraglottic structures. In children, it is best managed with a slow inhalational induction followed by intubation. Preparedness for emergent tracheostomy is essential.

87

The sensory level required to produce adequate anesthesia for a Cesarean section is:

T4
T6
T8
T10

T4: Cesarean section requires a T4 sensory level. Because of the high sympathetic blockade, all patients should receive a 1000 - 1500 mL bolus of lactated Ringer's prior to neural blockade.

88

The diagram below is consistent with:

normal neonatal anatomy
tetralogy of Fallot
transposition of the great vessels
truncus arteriosus

transposition of the great vessels

Transposition of the great vessels results from failure of the truncus arteriosus to spiral, resulting in the aorta arising from the anterior portion of the right ventricle and the pulmonary artery arising from the left ventricle. This results in two parallel and independent circulations and survival is not possible unless mixing of blood between the two circulations occurs through an ASD, VSD or PDA.

89

Five minutes after delivery of a 3.25-kg male the following is observed: pulse - 122, actively crying, active flexion and extension with stimulation and acrocyanosis. From this data the corresponding APGAR score is:

7
8
9
10

9
From the APGAR scoring table below, this neonate received a score of 2 for all parameters excepting color, for which he received a score of 1.
Parameter 0 1 2
Pulse Absent 100
Ventilation Absent Slow Crying
Reflexes None Grimace Crying
Tone` Limp Flexion Active
Color Pale Acrocyanosis Pink

90

Respiratory parameters that are increased during pregnancy include:

airway resistance
tidal volume
functional residual capacity
PaCO2

tidal volume
Oxygen consumption and minute ventilation progressively increase during pregnancy. Both tidal volume and rate increase. PaCO2 decreases and PaO2 increases slightly. Airway resistance declines about 35% during pregnancy and FRC is reduced by approximately 20%

91

In contrast to placenta previa, abruptio placentae:

usually occurs after 32 weeks of gestation
is associated with abdominal pain
poses little risk to the developing fetus
is not associated with coagulopathy

is associated with abdominal pain
The signs and symptoms of abruptio placentae are variable, but abdominal pain is always present, whereas placenta previa is associated with painless vaginal bleeding. Shock, coagulopathy, acute renal failure and fetal distress are also associated with abruptio placentae. Abruptio placentae is usually seen earlier in the pregnancy, after 20 weeks of gestation.

92

The blood/gas coefficients of volatile anesthetic agents:

are greater in the neonate than in the adult
are less in the neonate than in the adult
remain unchanged regardless of the age of the patient
are increased in preterm neonates, but normal in the full-term neonate

are less in the neonate than in the adult
The blood/gas coefficients of volatile anesthetics are lower in neonates than in adults, resulting in even faster induction times and potentially increasing the risk of overdosing.

93

Carboprost:

causes uterine relaxation
should only be administered intramuscularly
should only be given prior to delivery
is effective in reducing the need for Cesarean section

should only be administered intramuscularly
Carboprost tromethamine is a synthetic analogue of prostaglandin F2 that stimulates uterine contraction. it is often used to treat refractory post partum hemorrhage. As with methergine, it should be administered only intramuscularly.

94

Metabolic defects commonly seen in infants with pyloric stenosis include:

hypokalemia
acidosis
hyperchloremia
hypernatremia

hypokalemia
Persistent vomiting results in the progressive loss of gastric fluid, which contains sodium, potassium, chloride and hydrogen. Renal pH compensation causes further loss of potassium. These patients are dehydrated, hypokalemic and alkalotic. Hyponatremia may also be present.

95

Volatile anesthetic agents cross the placenta and enter the fetal circulation via:

breaks in the placental membrane
bulk flow
pinocytosis
diffusion

diffusion
Placental exchange can occur by one of five mechanisms: diffusion, bulk flow, active transport, pinocytosis and breaks in the placental membrane. Most drugs used in anesthesia have molecular weights well under 1000 and consequently can diffuse across the placenta.

96

Neonatal changes occurring upon delivery include:

lung expansion by the creation of negative 40 - 60 cm H2O intrathoracic pressure
anatomic closure of the ductus arteriosus
increased pulmonary vascular resistance secondary to lung expansion
increased thermogenesis from shivering

lung expansion by the creation of negative 40 - 60 cm H2O intrathoracic pressure
The initial negative intrathoracic pressures generated by the newborn are often in the range of 40 - 60 cm H2O. The increased arterial oxygen tension causes the ductus arteriosus to functionally close, however anatomic closure does not occur for 2 - 3 weeks. Heat production in the neonate is the result of non-shivering thermogenesis.

97

Following the use of epidural morphine for postoperative analgesia after a Cesarean section, several studies have reported an increased incidence of:

abdominal pain
recurrent herpes simplex labialis infection
septicemia
thrombocytopenia

recurrent herpes simplex labialis infection
An increased incidence (3.5 - 30%) of recurrent herpes simplex labialis infection had been reported 2 - 5 days following epidural morphine.

98

Congenital heart diseases associated with cyanosis include:

Eisenmenger's syndrome
ventricular septal defect
patent ductus arteriosus
coarctation of the aorta

Eisenmenger's syndrome
Patients with long-standing left-to-right intracardiac shunting may eventually develop increased pulmonary vascular resistance. When that resistance exceeds the systemic vascular resistance a reversal of the shunting can occur. These patients are said to have Eisenmenger's syndrome.

99

A 45-gestational-week-old neonate is scheduled for repair of a meningomyelocele. Anesthetic considerations include:

rapid sequence induction with the patient in the supine position
the use of deep neuromuscular blockade to prevent intraoperative movement
awake intubation in the lateral position
the use of radiant warmers to prevent heat loss from the meningomyelocele

awake intubation in the lateral position
Awake intubation in the lateral position is performed to avoid pressure on the meningocele sac. Long-acting muscle relaxants are avoided, allowing the surgeon to use nerve stimulators to identify functional neural elements. Although hypothermia is a frequent complication, care must be taken to prevent drying or thermal injury to the exposed neural tissue by the use of radiant heat lamps.

100

In the flow-volume loops below, normal is represented by loop B. The loop that best represents the maternal respiratory pattern during the third trimester is:

A
B
C
D

B

Flow-volume loops are unaffected by pregnancy and airway resistance decreases by about 35%.