Pediatrics

An $8$-week-old male infant is evaluated in the pediatric clinic for a two-week history of difficulty feeding. His parents report that he takes much longer to finish a bottle, becomes excessively sweaty during feeds, and seems to "breathe fast" constantly. He was born full-term at $39$ weeks gestation weighing $3.2\text{ kg}$. His current weight is $3.6\text{ kg}$. His temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), heart rate is $165/\text{min}$, respiratory rate is $68/\text{min}$, and blood pressure is $85/50\text{ mmHg}$. Oxygen saturation is $97\%$ on room air. Brachial and femoral pulses are equal and robust. Physical examination reveals a hyperactive precordium. Auscultation demonstrates a grade $4/6$ harsh holosystolic murmur at the left lower sternal border with a palpable thrill, and a faint mid-diastolic rumble at the cardiac apex. Lung examination reveals mild bilateral basilar crackles. The liver edge is palpated $3\text{ cm}$ below the right costal margin. Which of the following is the most appropriate next step in the management of this patient?

A 6-year-old boy is brought to the emergency department by his parents due to progressive lethargy, weakness, and severe pallor over the past 2 days. One week ago, he had a low-grade fever, rhinorrhea, and a brightly erythematous rash on both cheeks that spared his nasal bridge. His past medical history is significant for neonatal jaundice requiring 4 days of phototherapy. His father underwent a cholecystectomy at age 22. Vital signs show a temperature of 37.1°C (98.8°F), heart rate of 135/min, and blood pressure of 90/60 mm Hg. Physical examination reveals marked conjunctival pallor and a palpable spleen 4 cm below the left costal margin. Laboratory studies reveal the following:

Which of the following is the most likely primary mechanism for this patient's current severe anemia?

A 9-month-old male infant is brought to the emergency department due to sudden episodes of severe, inconsolable crying during which he draws his legs up to his abdomen. Between episodes, he appears lethargic but calm. The parents report one episode of dark, bloody, mucus-like stool on the way to the hospital. He is tachycardic but normotensive, and the abdomen is soft with a palpable 'sausage-shaped' mass in the right upper quadrant. Arrange the following steps in the correct chronological sequence for the evaluation and management of this patient.

A 12-month-old boy is brought to the pediatric genetics clinic for evaluation of global developmental delay and recurrent otitis media. His parents report that he sat independently at 9 months but is not yet crawling or pulling to stand. Vital signs are within normal limits. Physical examination reveals macrocephaly, a prominent forehead, thickened facial features, and a flattened nasal bridge. Ophthalmologic examination shows bilateral corneal clouding. Abdominal examination demonstrates a firm liver edge palpable 4 cm below the right costal margin and a palpable spleen tip. Initial skeletal radiography shows anterior beaking of the lumbar vertebrae and thickened, shortened diaphyses (dysostosis multiplex). The physician suspects a severe metabolic disorder.

Arrange the following diagnostic and management steps in the most appropriate chronological sequence for this patient, from initial evaluation to definitive long-term therapy.

A 3-year-old girl is rushed to the emergency department by her parents due to sudden onset of high fever, severe sore throat, and difficulty breathing. The family recently immigrated, and the child has not received any childhood immunizations. On examination, the patient appears toxic, is leaning forward with her neck extended, and is drooling. Her temperature is 39.4°C (102.9°F), heart rate is 150/min, and respiratory rate is 42/min. She has prominent suprasternal retractions and a muffled, "hot potato" voice. Inspiratory stridor is audible without a stethoscope.

Arrange the following steps in the management of this patient in the most appropriate chronological order from first to last.

An $8$-day-old male infant is brought to the emergency department via ambulance after several episodes of dark green vomiting. The mother reports that the infant has been increasingly lethargic over the past $12$ hours and has not produced a wet diaper since yesterday. Vital signs include a temperature of $35.4^\circ \text{C}$ ($95.7^\circ \text{F}$), heart rate of $195$/min, respiratory rate of $65$/min, and blood pressure of $52/28$ mm Hg. Physical examination reveals an ill-appearing, mottled infant. The abdomen is markedly distended and exquisitely tender to palpation, demonstrating involuntary guarding. A localized area of cutaneous erythema and edema is noted extending across the right hemiabdomen. The skin over the trunk shows scattered blanching erythematous macules with central yellow papules, which the mother states have been present since hospital discharge. Capillary refill is $5$ seconds. Arterial blood gas analysis on room air shows a pH of $7.20$, $\text{pCO}_2$ of $20$ mm Hg, and $\text{HCO}_3^-$ of $8$ mEq/L. Which of the following is the most appropriate next step in the management of this patient?

A 12-day-old girl is brought to the emergency department by her parents due to two days of worsening vomiting, hypotonia, and decreased responsiveness. She was born at 39 weeks gestation and was feeding well on standard infant formula until this episode. Her temperature is 36.5°C (97.7°F), heart rate is 170/min, and respiratory rate is 68/min with deep, rapid breaths. Physical examination shows a lethargic neonate with dry mucous membranes and decreased muscle tone.

Laboratory studies show the following:

Arterial blood gas analysis on room air shows a pH of 7.20 and a $pCO_2$ of 23 mm Hg. Urinalysis demonstrates large ketones but is negative for reducing substances. Further metabolic testing reveals markedly elevated serum propionic acid and methylcitric acid levels, with normal methylmalonic acid levels.

Which of the following is the most appropriate specific long-term dietary management for this patient's underlying condition?

Match each pediatric cardiovascular clinical presentation with its most appropriate targeted therapeutic intervention.

An 8-month-old male infant presents for a routine wellness examination accompanied by his parents. The family is anxious because the child is not yet walking on his own and has not started speaking in two-word sentences. Upon physical evaluation, the clinician notes that the infant exclusively uses his right hand to grasp objects while keeping his left hand tightly clenched. Neurological assessment demonstrates increased muscle tone and hyperactive deep tendon reflexes in the left upper and lower extremities. A review of his past medical history reveals he was delivered prematurely at 29 weeks of gestation. The clinician suspects spastic hemiplegic cerebral palsy. Which of the following statements regarding this patient's clinical presentation and appropriate management are correct? (Select 2)

A 4-day-old term female infant is brought to the emergency department by her parents due to multiple episodes of green-tinged vomiting that began 6 hours ago. She has been exclusively breastfed and previously had normal stooling and wet diapers. Her temperature is 37.1°C (98.8°F), heart rate is 148/min, respiratory rate is 42/min, and blood pressure is 76/42 mm Hg. Physical examination reveals a soft, non-distended, and non-tender abdomen with active bowel sounds. Capillary refill time is 2 seconds. Arrange the following steps in the most appropriate sequence for the evaluation and management of this patient, from the first step to the definitive final step.

Match each classic clinical presentation and associated diagnostic imaging finding with the most appropriate pediatric gastrointestinal diagnosis.

Paramedics bring a $9$-year-old girl to the emergency department due to acute-onset, severe shortness of breath. She has a history of moderate persistent asthma but exhausted her supply of inhaled fluticasone-salmeterol two months ago. Her symptoms began abruptly after she visited a relative's house that has multiple indoor cats. In the emergency department, she receives three continuous nebulized treatments of albuterol and ipratropium, along with a dose of intravenous methylprednisolone. Reassessment $45$ minutes later reveals a temperature of $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), heart rate of $148/\text{min}$, and respiratory rate of $38/\text{min}$. Pulse oximetry is $91\%$ on a $4\text{ L/min}$ nasal cannula. On examination, the patient appears exhausted and somnolent. She is sitting in a tripod position and using prominent suprasternal and intercostal accessory muscles to breathe. Chest auscultation reveals a "silent chest" with markedly diminished air entry bilaterally and no audible wheezing. Arterial blood gas analysis on supplemental oxygen reveals a $\text{pH}$ of $7.31$, $\text{PaCO}_2$ of $46 \text{ mmHg}$, and $\text{PaO}_2$ of $62 \text{ mmHg}$. Which of the following is the most appropriate next step in management?

A $4$-day-old male infant born at term is admitted to the neonatal intensive care unit with progressive lethargy, hypothermia, and poor feeding over the past $24$ hours. Physical examination reveals a somnolent neonate with profound hypotonia and tachypnea. Initial laboratory studies show a severe respiratory alkalosis and a serum ammonia level of $1,250 \mu\text{mol/L}$ (normal: $15$-$50 \mu\text{mol/L}$). There is no metabolic acidosis or ketosis. The clinical team suspects a urea cycle disorder and recognizes a severe hyperammonemic crisis. Arrange the following interventions in the most appropriate chronological sequence for the acute management of this patient.

An $11$-month-old boy is rushed to the emergency department due to a sudden episode of severe cyanosis and unresponsiveness. The parents report that the child became extremely agitated and inconsolable during a blood draw at a local clinic, after which his lips and fingers turned deep blue. He has a history of an uncorrected congenital heart defect for which he is awaiting surgical repair. On arrival, the child is lethargic. Vital signs show a heart rate of $175/\text{min}$, respiratory rate of $55/\text{min}$, and oxygen saturation of $65\%$ on room air. Physical examination reveals a harsh, grade 4/6 systolic ejection murmur at the left mid-to-upper sternal border and a single S2. The emergency physician immediately places the infant in a knee-chest position and applies $100\%$ supplemental oxygen via a non-rebreather mask. Intravenous morphine and a normal saline bolus are administered. Ten minutes later, the infant's oxygen saturation remains at $68\%$. Which of the following is the most appropriate next pharmacologic intervention and its primary physiologic mechanism in this patient?

A 48-hour-old full-term male neonate is evaluated in the nursery because he has not yet passed meconium. The nurses report that the infant has had three episodes of bilious vomiting in the past 12 hours. On physical examination, the infant's abdomen is visibly distended and tympanitic. During a digital rectal examination, there is an explosive release of gas and foul-smelling stool, after which the abdomen becomes notably less distended. Which of the following is the most likely underlying pathophysiology of this patient's presentation?

A 9-month-old boy arrives at the emergency department accompanied by his parents after a frightening episode at home. His mother reports that while he was crying vigorously during a diaper change, his lips, hands, and feet suddenly turned a deep blue color, and he appeared unusually limp. The mother instinctively held him tightly with his knees tucked against his chest, and his normal skin color slowly returned over 15 minutes. The infant was diagnosed with a heart murmur in the neonatal nursery but missed his scheduled cardiology follow-up. Current vital signs are temperature 37.0°C (98.6°F), heart rate 138/min, respiratory rate 32/min, and blood pressure 94/56 mm Hg. Oxygen saturation is 93% on room air. Cardiac auscultation reveals a prominent right ventricular heave, a single S2, and a grade 3/6 harsh, crescendo-decrescendo systolic murmur heard best at the left mid-to-upper sternal border. The remainder of the physical examination is unremarkable. If a similar hypercyanotic episode occurs during evaluation and fails to improve with supplemental oxygen and knee-chest positioning, which of the following is the most appropriate next pharmacologic step in management?

A 7-year-old boy with a history of moderate persistent asthma is brought to the emergency department for severe shortness of breath. He is speaking in single words, sitting in a tripod position, and using accessory muscles to breathe. Physical examination reveals diffuse expiratory wheezing and a prolonged expiratory phase. His oxygen saturation is 88% on room air. Arrange the following steps in the most appropriate sequential order for the acute management of this patient.

A 5-year-old boy is brought to the emergency department by his parents due to extreme fatigue, decreased urination over the past 24 hours, and a new rash. One week ago, he had a 3-day episode of severe, bloody diarrhea accompanied by abdominal cramps, which was treated with oral ciprofloxacin at an urgent care clinic. Today, he appears pale and lethargic. Vitals show a temperature of $37.2^\circ\text{C}$, heart rate of $135/\text{min}$, respiratory rate of $24/\text{min}$, and blood pressure of $118/78 \text{ mmHg}$. Physical examination reveals scleral icterus and scattered petechiae over the lower extremities. The abdomen is soft and non-tender with no hepatosplenomegaly. Laboratory studies show:

A peripheral blood smear demonstrates numerous fragmented red blood cells. Which of the following is the most appropriate next step in the management of this patient?

During a busy winter shift at the pediatric emergency department, a $6$-week-old female infant is triaged for severe respiratory distress. The parents describe a prodrome of clear rhinorrhea and a mild cough that began $4$ days prior. However, since this morning, she has been refusing to feed and appears to be struggling for each breath. She was born via spontaneous vaginal delivery at $39$ weeks gestation with an uncomplicated postnatal course.

Vital signs are as follows:
- Temperature: $37.6^\circ\text{C}$ ($99.7^\circ\text{F}$)
- Heart rate: $172$/min
- Respiratory rate: $70$/min
- Blood pressure: $85/50$ mm Hg
- Oxygen saturation: $85\%$ on room air

Physical examination reveals an ill-appearing infant with marked head bobbing, severe intercostal and subcostal retractions, and prominent nasal flaring. Lung auscultation demonstrates bilateral diffuse fine crackles and high-pitched expiratory wheezing. Capillary refill time is $3$ seconds.

Which of the following therapies are currently indicated for this patient? (Select all that apply)

Correctly map each pediatric patient's specific clinical vignette to the corresponding underlying biochemical or genetic defect.