PEDIATRICS | Advanced Flashcards
Which of the following is the primary physiologic response in a neonate exposed to a hypothermic environment?
(A) Hyperventilation
(B) Increased 2,3-DPG concentration in erythrocytes
(C) Metabolism of brown fat
(D) Shivering
(E) Vasoconstriction
C. Metabolism of brown fat
A 14-month-old child has tetralogy of Fallot with dynamic obstruction to right ventricular outflow. Which of the following is most likely to decrease cyanosis in this child?
A. Calcium
B. Epinephrine
C. Nitroglycerin
D. Nitroprusside
E. Propranolol
E. Propranolol
After an uncomplicated cesarean delivery, a full-term neonate has intermittent cyanosis. Diaphragmatic effort is vigorous and respiratory distress is relieved while crying. The most likely diagnosis is:
A. Amniotic fluid aspiration
B. Choanal atresia
C. Diaphragmatic hernia
D. Tetralogy of Fallot
B. Choanal atresia
Which of the following comorbidities is MOST strongly associated with an increased risk of central postoperative apnea in a preterm infant?
A. Gastroschisis
B. Anemia
C. Myelomeningocele
D. Omphalocele
B. Anemia
There is a high incidence of central postoperative apnea in former preterm infants who present for surgery. Apnea most commonly develops in patients younger than 46 weeks postconceptual age (PCA); however, apnea has been reported up to 60 weeks PCA.
Anemia (hematocrit <30%) is a potent, independent risk factor associated with apnea in former preterm infants. Routine, preoperative assessment for anemia should performed in former premature infants because the risk for apnea in anemic former preterm infants is not altered by postconceptual or gestational age.
Which of the following DOES not exhibit a Right-to-Left Shunt?
A. Truncus Arteriosus
B. Tricuspid atresia
C. Tetralogy of Fallot
D. TAPVR
E. PDA
E. PDA
The 5 T’s of Right-to-Left Shunts
- Truncus Arteriosus
- Transposition
- Tricuspid atresia
- Tetralogy of Fallot
- TAPVR
Which of the following is NOT needed for a drug to cross the placenta?
A. Low molecular weight
B. High lipid solubility
C. Non-ionized form
D. Non-polar
E. Ionized form
E. Ionized form
For a drug/molecule to cross the PLACENTA, it has to be:
Non-Polar, Non-ionized, LOW molecular weight and HIGH lipid solubility
Which of the following sets of data BEST represents an umbilical arterial blood gas analysis from a normal, healthy fetus immediately following delivery?
Data presented as: pH / PaCO2 (mm Hg) / PaO2 (mm Hg) / Bicarbonate (mEq/L) / Base excess (mEq/L).
A) 7.03 / 63 / 14 / 16 / –10
B) 7.24 / 52 / 22 / 23 / –3
C) 7.35 / 41 / 33 / 24 / –1
D) 7.41 / 39 / 98 / 25 / 0
B) 7.24 / 52 / 22 / 23 / –3
Umbilical cord blood gas analysis (or fetal scalp blood analysis) can be used to objectively assess a fetus’s or neonate’s condition before, during, or following delivery.
When measuring an umbilical cord blood sample, it is important to recall that the umbilical arteries are carrying blood away from the fetus and that a normal sample will appear “venous.” Similarly, a normal umbilical venous blood gas sample will appear “arterial,” as it is carrying maternal arterial blood to the fetus.
In fact, an umbilical venous blood gas sample can be used to assess the mother’s acid-base status.
The normal average values of an umbilical artery blood gas sample are approximately: pH 7.2-7.3, PaCO2 50-55 mm Hg, PaO2 18-25 mm Hg, bicarbonate 22-25 mEq/L, base excess –2.7 to –4.7 mEq/L.
Which of the following statements regarding the anatomic and physiologic development of the newborn respiratory system is TRUE?
A) Lung compliance is reduced, but relative chest wall compliance is higher compared to adults
B) The neonatal diaphragm has a higher percentage of type I muscle fibers
C) The pulmonary system continues to grow and mature until approximately 12 months of age
A) Lung compliance is reduced, but relative chest wall compliance is higher compared to adults
The infant lung is less compliant compared to adults, while the chest wall is relatively more compliant.
The infant airway has several key anatomical differences compared to adults. Infants have a larger occiput; are obligate nose breathers despite having smaller nasal passages; and have relatively larger tongues, longer epiglottis, shorter trachea, and a more cephalad larynx (C3-4) compared to adults (C5-6).
These can lead to challenges in airway management. The physiology of the infant respiratory systems also differs from adults and has significant effects on anesthetic management.
Oxygen consumption is much higher in children.
It is estimated that, under general anesthesia, a healthy adult has a basal oxygen requirement of 2 to 4 mL/kg/min, while a healthy infant has an oxygen requirement of 6 to 9 mL/kg/min. To account for this increased demand, infants maintain significantly higher alveolar ventilation compared to adults.
This leads to more rapid
inhalational induction and anesthetic emergence. In addition, this results in a faster onset of hypoxia and hypercapnia during periods of inadequate ventilation. In addition, infants have immature hypoxic and hypercapnic respiratory drives that further contribute to the risk of hypoxemia. Tidal volumes in infants and children are comparable to adults in a volume-to-body weight ratio.
In an awake infant, functional residual capacity (FRC) is also similar to adults on a volume-to-body weight ratio; however, FRC is significantly reduced in an anesthetized infant, and this also contributes to the rapid onset of hypoxia.
Compared with normal adults, which of the following characteristics of neonates best explains the more rapid inhalation induction in neonates?
(A) Greater cardiac index
(B) Greater metabolic rate
(C) Greater perfusion of vessel-rich tissues
(D) Greater ratio of alveolar ventilation to functional residual capacity
(E) Less lean body mass
(D) Greater ratio of alveolar ventilation to functional residual capacity
During an inguinal hernia repair, a newborn infant will have a larger fluid requirement (in milliliters per kilogram) than an adult because of relatively greater
(A) insensible water loss
(B) lean body mass
(C) metabolic rate
(D) sodium loss
(E) third space losses
(C) metabolic rate
A newborn is in respiratory distress. Examination shows a scaphoid abdomen, cyanosis while breathing oxygen by mask, and heart sounds in the right hemithorax. Which of the following is the most appropriate next step?
(A) Assisted ventilation with a bag and face mask
(B) Insertion of a chest tube on the left side
(C) Insertion of a nasogastric tube
(D) Tracheal intubation and assisted ventilation
(E) Tracheal intubation and expansion of the left lung
(D) Tracheal intubation and assisted ventilation
Diagnosis: Congenital Diaphragm Hernia
The diagnosis of CDH can be made prenatally by fetal ultrasonography or fetal magnetic resonance imaging.
The infant has a scaphoid abdomen secondary to the absence of intra-abdominal contents, which have herniated into the chest. Breath sounds on the affected side are reduced or absent.
Which of the following is NOT appropriate in terms of peri-operative management of CDH?
A. acidosis can precipitate pulmonary hypertension
B. permissive hypercapnia is instituted to reduce mortality
C. Left sided CDH has higher morbidity and mortality
D. For those with mild form and no respiratory distress, it may be beneficial to avoid intraoperative opioids and provide regional or neuraxial analgesia
C. Left sided CDH has higher morbidity and mortality
Which of the following should be included in the preoperative management of a 12-year-old patient with Duchenne’s muscular dystrophy who is unable to ambulate?
(A) Determination of serum creatine kinase concentration
(B) Determination of serum potassium concentration
(C) Liver function profile
(D) Echocardiography
(E) Dantrolene prophylaxis
(D) Echocardiography
Cardiac evaluation is recommended every 2 years after diagnosis up until the age of 10.
Most patients with DMD die before their fourth
decade of life. Cardiac and respiratory complications are the most common causes of death.
Compared with the adult airway, the neonatal airway has which of the following characteristics?
(A) More cephalad larynx
(B) Narrowest diameter at the vocal cords
(C) Relatively smaller epiglottis
(D) Smaller tongue relative to the size of the oral cavity
(E) Vocal cords perpendicular to the trachea
(A) More cephalad larynx
