neonatology Flashcards
A female infant born at 26 weeks’ gestational age required tracheal intubation and ventilator management for 6 weeks. She then underwent extubation and was placed on nasal continuous positive airway pressure (CPAP) and eventually weaned to nasal cannula oxygen at 0.1 L/min. Since her discharge from the hospital at 4 months of age, the girl has had poor growth and repeated episodes of respiratory illness with noisy breathing, stertor, and coarse wheezing that does not respond to inhaled bronchodilators. She is currently 9 months old, and her growth trajectory has continued to decline since hospital discharge despite high-calorie infant formula and additional nutritional support.
Of the following, the MOST accurate statement regarding this girl’s symptoms is that
A. she will likely require tracheostomy and long-term ventilator management B. the noisy breathing and stertor are likely to improve by 18 to 24 months of age C. use of inhaled corticosteroids will improve her wheezing D. use of inhaled ipratropium may be beneficial
use of inhaled corticosteroids will improve her wheezing
Tracheomalacia is common in premature infants.
Most congenital tracheomalacia will improve with time and maturity.
Critical tracheomalacia may require long-term intubation and mechanical ventilation.
Premature infants and those who have had tracheal intubation are the patients most at risk for tracheomalacia.
Most infants with tracheomalacia will improve by 18 to 24 months of age and do not have respiratory compromise requiring ventilator support.
A 24-hour-old term neonate is being evaluated. He was born at 38 weeks’ gestation by cesarean delivery after failed induction for maternal preeclampsia; his birthweight was 3.6 kg. Since birth, he has breastfed 8 times. His nurse reports a good latch. He has had 1 meconium stool and 2 wet diapers. His weight is 3.2 kg and his physical examination findings are unremarkable.
Of the following, the clinical information that SUPPORTS the decision not to supplement with formula is
A. the neonate’s sex B. gestational age C. history of maternal preeclampsia D. mode of delivery
mode of delivery
or full-term neonates, loss of 7% to 10% of birthweight is acceptable and not unexpected over the first week after birth.
Neonates born via cesarean section may lose more weight in the first 2 days after birth than those delivered vaginally.
In an exclusively breastfed neonate, weight loss of greater than 10% in the first 24 to 48 hours after birth should alert clinicians to the possibility of problems with breastfeeding.
n the first 24 to 48 hours after birth, as adequate renal function is established, there is a natural diuresis, likely from the extracellular space. This is followed by an expected weight gain of 15 g/day with adequate oral intake.
A 25-hour-old neonate with abdominal distention is being evaluated. His 34-year-old mother has gestational diabetes controlled by diet; her hemoglobin A1c level is 6.6%. Echogenic bowel was noted on prenatal ultrasonography. He was delivered vaginally with an Apgar score of 9 at 1 and 5 minutes. He has breastfed 6 times with a good latch. He has not yet had a bowel movement. On physical examination, the neonate appears comfortable. He has a prominent white forelock, barrel-shaped chest, moderate abdominal distention, and decreased bowel sounds (Item Q114A). Abdominal radiography is performed (Item Q114B).
Of the following, the MOST likely diagnosis for this neonate is
A. Hirschsprung disease
B. inadequate oral intake
C. necrotizing enterocolitis
D. small left colon syndrome
Hirschsprung disease
Hirschsprung disease typically presents in the neonatal period with delayed passage of meconium, abdominal distention, and feeding intolerance.
Waardenburg syndrome is characterized by a prominent white forelock, wide nasal bridge, sensorineural deafness, heterochromia iridis, and in some types, lateral displacement of the inner canthi.
Waardenburg syndrome type 4 (Waardenburg-Shah syndrome) is always associated with Hirschsprung disease.
Waardenburg syndrome (WS) is inherited in an autosomal dominant pattern
A neonate is born at term via precipitous vaginal delivery to a 22-year-old woman who recently emigrated from El Salvador and did not receive any prenatal care. A rapid human immunodeficiency virus test and rapid plasma reagin test performed on the mother soon after delivery have negative results. The neonate weighs 2.2 kg and has microcephaly. He is alert and has a good cry, normal tone, and normal activity. Red reflex is decreased in the right eye and absent in the left eye. He has mild hepatosplenomegaly, petechiae, and a grade 2/6 systolic ejection murmur on auscultation of the left upper chest. The remainder of his physical examination findings are unremarkable. Laboratory data are notable for thrombocytopenia. A computed tomographic scan of the head reveals calcifications. Audiologic evaluation reveals absent auditory brainstem responses in both ears. Skeletal survey shows the presence of transverse lucent bands in both proximal humeral metaphyses. Evaluation by an ophthalmologist reveals bilateral cataracts.
Of the following, the MOST likely etiology for the findings in this neonate is
A. cytomegalovirus B. rubella C. syphilis D. toxoplasma
rubella
Rubella virus infection of the mother during pregnancy can lead to congenital rubella syndrome, miscarriage, or fetal demise.
The risk of congenital rubella syndrome is highest among neonates born to mothers immigrating to the United States from low-income and middle-income countries because they have received no or incomplete immunizations.
The most common manifestations of congenital rubella syndrome include microcephaly, cataracts, sensorineural deafness, peripheral pulmonic stenosis, and radiolucent bone lesions.
A male neonate is evaluated in the nursery. He is stable on room air. He has midface hypoplasia, up-slanting palpebral fissures, epicanthal folds, single transverse palmar crease, and wide gaps between the first and second toes. An echocardiogram shows an atrioventricular canal defect. A karyotype for the neonate shows trisomy 21 with an unbalanced translocation of chromosomes 14 and 21. On the basis of this result, karyotypes for both parents are recommended.
Of the following, the karyotype that carries the HIGHEST risk of recurrence of this syndrome for these parents in subsequent pregnancies is
A. 45,XY,t(14;21) in the father B. 45,XX,t(14;21) in the mother C. 46,XY,t(14;21) in the newborn D. 47,XY,+21 in the newborn
45,XX,t(14;21) in the mother
Down syndrome is caused by an extra chromosome 21.
Recurrence risk is higher if the mother is a carrier of a balanced translocation and lowest if the child has a freestanding chromosome 21.
A freestanding extra chromosome 21 arises because of meiotic nondisjunction, which in 90% of cases is maternal in origin. The risk of parents’ having another child with Down syndrome with this karyotype would be 1% above the age-adjusted risk of the mother in subsequent pregnancy.
A 35-week-gestation female neonate is delivered at home precipitously. Her mother had routine prenatal care. The father drives the mother and neonate to the nearest hospital, with the mother holding the neonate in a wet receiving blanket. On arrival at the emergency department, the neonate has a temperature of 35.6°C, heart rate of 92 beats/min, respiratory rate of 15 breaths/min, blood pressure of 55/37 mm Hg, and oxygen saturation on pulse oximetry of 87% in room air. Her extremities are cool.
Of the following, the MOST likely mechanism for the neonate’s heat loss is
A. conductive
B. convective
C. evaporative
D. radiant
evaporative
There are 4 primary mechanisms for heat loss in a neonate: evaporative, convective, conductive, and radiant.
Evaporative heat loss is significant in neonates in part because of their high surface area-to-volume ratio.
Immediate skin-to-skin care after delivery is an effective means of preventing hypothermia in term neonates.
The wet blanket wrapped around the neonate allows continuous evaporative heat loss. Radiant heat loss refers to heat loss to the surrounding air. Because the neonate is covered with a blanket, there is likely minimal radiant heat loss. Conductive heat loss describes thermal energy transferred to an adjacent object. Because the neonate is being held by her mother, conductive heat loss should be minimal. Convective heat loss is loss of heat because of moving air around the neonate. If this neonate were exposed to air conditioning or air drafts, the convective heat loss could be more significant.
