Pediatrics

A female infant born at 26 weeks gestation is evaluated in the neonatal intensive care unit on day 16 of life. The nursing staff notes that she has become increasingly lethargic over the last 6 hours and has had multiple episodes of apnea and bradycardia. She has been tolerating small volumes of expressed breast milk via an orogastric tube. Vital signs show a temperature of 35.1°C (95.2°F), heart rate of 178/min, and blood pressure of 42/22 mm Hg. Physical examination reveals a tense, shiny, and grossly distended abdomen with absent bowel sounds. Capillary refill time is 4 seconds. Laboratory studies demonstrate a leukocyte count of 3,200/mm³ and a serum bicarbonate of 11 mEq/L. A supine anteroposterior abdominal radiograph displays air in the bowel wall and a distinct area of radiolucency outlining the falciform ligament. Which of the following is the most appropriate next step in management?

During a busy winter shift in the pediatric emergency department, a physician evaluates an infant born at term who is now 7 months of age. The child's parents report a three-day prodrome of rhinorrhea and low-grade pyrexia, which has recently progressed to marked work of breathing and a refusal to breastfeed. Vital signs demonstrate a temperature of 37.9°C (100.2°F), respiratory rate of 74/min, heart rate of 172/min, and a pulse oximetry reading of 87% on ambient air. Physical examination reveals an irritable infant with significant nasal flaring, prominent suprasternal retractions, and diffuse bilateral polyphonic wheezes and fine crackles. The child has no history of atopy, eczema, or previous wheezing episodes. Which of the following interventions represent appropriate management for this patient? (Select exactly 2 options)

An $8$-year-old boy with a known history of severe hemophilia A is brought to the emergency department by his parents after falling from a tree and striking his head. The parents report a brief loss of consciousness. He is now awake but complains of a severe headache and has vomited twice. His vital signs are temperature $37.1^\circ\text{C}$, heart rate $110\text{ /min}$, blood pressure $115/75\text{ mmHg}$, and respiratory rate $20\text{ /min}$. Physical examination reveals a large boggy hematoma over the right parietal region. Neurologic examination shows a Glasgow Coma Scale score of $14$ (confused conversation). Arrange the following management steps in the most appropriate chronological order for this patient.

Match each of the following definitive histopathologic or mucosal biopsy findings to the corresponding pediatric gastrointestinal disorder it most accurately diagnoses.

A 14-month-old infant is brought to the emergency department with a 3-day history of severe watery diarrhea and non-bilious vomiting. On examination, the infant is lethargic, has sunken eyes, dry mucous membranes, and a delayed capillary refill of 4 seconds. Vital signs show a heart rate of 170/min, respiratory rate of 40/min, and blood pressure of 70/40 mmHg. Arrange the following management steps in the correct sequential order from immediate priority to subsequent care.

A 4-year-old unimmunized boy is brought to the emergency department by his parents due to the sudden onset of a high fever and difficulty breathing. His parents state that he was well yesterday but woke up this morning complaining of a severe sore throat and pain with swallowing. In the exam room, the child appears toxic, anxious, and is leaning forward with his neck extended and mouth open. He is actively drooling. His temperature is $39.5^\circ\text{C}$ ($103.1^\circ\text{F}$), heart rate is $145/\text{min}$, respiratory rate is $32/\text{min}$, and oxygen saturation is $94\%$ on room air. Inspiratory stridor is audible without a stethoscope.

Arrange the following steps in the most appropriate chronological order for the management of this patient.

The parents of a 6-month-old boy of Mediterranean descent bring him to the clinic for a routine evaluation. They report that he has been increasingly fussy, easily fatigued, and feeding poorly over the past month. The parents also express two additional concerns: they are worried because he cannot sit up independently, and they request he receive his measles, mumps, and rubella (MMR) vaccine today to finish his immunizations early. He was born at full term, and his growth has consistently tracked along the 50th percentile. His temperature is $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), heart rate is $155/\text{min}$, and respiratory rate is $36/\text{min}$. On physical examination, the infant appears notably pale. A grade 2/6 systolic ejection murmur is auscultated at the left lower sternal border. The liver edge is palpated $3\text{ cm}$ below the right costal margin, and the spleen is palpable $4\text{ cm}$ below the left costal margin. Neurologic examination reveals normal symmetric tone; he sits with truncal support and successfully rolls from front to back.

Laboratory testing reveals:
Hemoglobin: $6.2\text{ g/dL}$
Mean corpuscular volume (MCV): $62\text{ fL}$
Reticulocyte count: $7\%$
Thyroid-stimulating hormone (TSH): $2.5\text{ \mu U/mL}$ (normal: $0.5-5.0\text{ \mu U/mL}$)
Free T4: $1.4\text{ ng/dL}$ (normal: $0.9-2.3\text{ ng/dL}$)

A peripheral blood smear shows microcytic, hypochromic red blood cells with numerous target cells.

Which of the following is the most appropriate next step in the management of this patient?

Evaluate the following histologic, cytogenetic, and clinical descriptions. Pair each specific finding with its corresponding pediatric hematologic or oncologic diagnosis.

A 2-day-old full-term male neonate is evaluated in the neonatal intensive care unit for progressive abdominal distension and bilious emesis. The infant has not passed meconium since birth. Vital signs are within normal limits. Physical examination reveals a markedly distended, tympanic abdomen. Digital rectal examination produces a forceful expulsion of foul-smelling gas and stool, which temporarily relieves the distension. Arrange the following steps in the most appropriate sequential order for the diagnostic evaluation and management of this patient's most likely condition.

A 14-month-old boy is evaluated in the pediatric ward due to a new-onset fever and worsening work of breathing. He was admitted 3 days ago for respiratory distress secondary to respiratory syncytial virus (RSV) bronchiolitis. Yesterday, he was weaning off supplemental oxygen and tolerating oral feeds well. Today, his temperature is 39.0°C (102.2°F), blood pressure is 90/55 mm Hg, pulse is 155/min, and respiratory rate is 55/min. Pulse oximetry shows 91% on room air. Physical examination reveals intercostal retractions and new localized crackles over the right lower lung field, along with persistent diffuse expiratory wheezing. A chest radiograph demonstrates a new lobar consolidation in the right lower lobe. Blood cultures obtained during a febrile episode earlier today are rapidly growing Streptococcus pneumoniae that is susceptible to penicillin. Which of the following interventions are indicated in the current management of this patient? (Select all that apply)

During a routine well-child visit, the mother of a $4$-year-old girl expresses concern about multiple new bruises on her daughter's legs over the past few days. The mother notes the child had a self-resolving upper respiratory tract infection approximately three weeks prior. The patient is otherwise active and has no history of excessive bleeding, epistaxis, or melena. Physical examination reveals a well-appearing, playful child. Vital signs are within normal limits for age. Skin examination shows scattered petechiae and small ecchymoses confined to the bilateral lower extremities. There is no jaundice, lymphadenopathy, or hepatosplenomegaly.

Laboratory evaluation demonstrates:
Hemoglobin: $12.8 \text{ g/dL}$
Leukocyte count: $8,200/\text{mm}^3$ (normal differential)
Platelet count: $16,000/\text{mm}^3$

Which of the following is the most appropriate next step in management for this patient?

A $6$-year-old boy is brought to the clinic by his parents due to fatigue and yellowish discoloration of his eyes for the past $3$ days. He had a mild upper respiratory tract infection one week ago. His past medical history is unremarkable, and his immunizations are up to date. Family history is notable for a paternal aunt who underwent an unexplained splenectomy in her twenties. Vital signs are within normal limits. Physical examination reveals scleral icterus, pale conjunctivae, and a palpable spleen edge $4 \text{ cm}$ below the left costal margin. Laboratory studies show the following:

Direct antiglobulin (Coombs) testing is negative.

Which of the following is the most appropriate next step in diagnostic evaluation?

A 4-year-old boy is brought to the pediatric emergency department by his parents due to recurrent episodes of severe abdominal pain that started 12 hours ago. During the episodes, he cries inconsolably and pulls his knees to his chest; between episodes, he appears exhausted and lethargic. He has had two episodes of bilious emesis. His last bowel movement consisted of dark red, gelatinous stool. Temperature is 37.2°C (99.0°F), heart rate is 125/min, blood pressure is 95/60 mm Hg, and respiratory rate is 24/min. Physical examination reveals a palpable, sausage-shaped mass in the right middle quadrant. An abdominal ultrasound demonstrates a "target sign." An ultrasound-guided hydrostatic enema is performed, successfully reducing the obstruction. A detailed post-reduction ultrasound identifies a 3.5-cm blind-ending tubular structure protruding from the antimesenteric border of the distal ileum. The patient is now pain-free and resting comfortably. Which of the following is the most appropriate next step in management?

A 2-year-old boy is brought to the emergency department by his parents after they found a large amount of maroon-colored stool in his diaper. The parents report that the child has had no episodes of emesis, diarrhea, or apparent abdominal pain. He has been active and playing normally at home today. His medical history is unremarkable, and his immunizations are up to date. His temperature is 36.9°C (98.4°F), heart rate is 112/min, respiratory rate is 22/min, and blood pressure is 92/58 mm Hg. On physical examination, the child appears comfortable and in no acute distress. The abdomen is soft, non-tender, and non-distended, with no palpable masses. Bowel sounds are active. Inspection of the perianal area shows no fissures. Laboratory studies reveal a hemoglobin of 10.2 g/dL and a mean corpuscular volume of 78 fL. Which of the following is the most appropriate next step in evaluating this patient's condition?

Concerned parents bring their 5-month-old son to the acute care clinic in mid-December. They report that for the past 24 hours, the infant has been breathing very rapidly and refusing his formula. His symptoms began 3 days earlier with clear rhinorrhea and a tactile fever. His medical history includes delivery at 31 weeks of gestation. Current vital signs indicate a temperature of 38.1°C (100.6°F), heart rate of 158/min, and respiratory rate of 70/min. Pulse oximetry demonstrates an oxygen saturation of 88% while breathing room air. On examination, the infant exhibits grunting, severe subcostal retractions, and widespread expiratory wheezing mixed with fine crackles on auscultation. Which of the following best describes the predominant underlying mechanism responsible for this patient's respiratory distress?

Match each pediatric patient's clinical presentation with the most likely corresponding imaging finding.

A 3-month-old infant is admitted to the pediatric intensive care unit with severe respiratory syncytial virus (RSV) bronchiolitis. Over the next 24 hours, the infant's condition progressively deteriorates, demonstrating worsening tachypnea, severe intercostal retractions, and increasing oxygen requirements. The clinical team must escalate respiratory support as the infant progresses toward impending respiratory failure. Arrange the following respiratory interventions in the standard step-wise escalation sequence, starting with the least invasive initial measure and ending with the most advanced rescue therapy.

Match the following classic radiologic findings with the most appropriate pediatric gastrointestinal pathology.

A $9$-year-old boy is diagnosed with Burkitt lymphoma after presenting with a rapidly enlarging abdominal mass and abdominal pain. Laboratory studies reveal a white blood cell count of $14,000/\text{mm}^3$, a uric acid level of $11.2 \text{ mg/dL}$, potassium of $5.1 \text{ mEq/L}$, phosphorus of $6.5 \text{ mg/dL}$, and calcium of $7.2 \text{ mg/dL}$. His serum creatinine is $0.8 \text{ mg/dL}$. He is admitted to the pediatric intensive care unit for management. Arrange the following steps in the most appropriate chronological order for the prevention and management of tumor lysis syndrome (TLS) and its potential complications in this patient, starting from the initial intervention upon admission.

An 8-week-old male infant is brought to the emergency department by his parents due to a 24-hour history of severe abdominal distension, lethargy, and multiple episodes of explosive, foul-smelling diarrhea. His mother notes he has been feeding poorly and had two episodes of nonbilious emesis this morning. The patient's past medical history is notable for delayed passage of meconium, which required glycerin suppositories during his first week of life, and he has suffered from chronic constipation since discharge. His temperature is $38.9^\circ C$ ($102^\circ F$), blood pressure is $65/35\text{ mm Hg}$, pulse is $188/\text{min}$, and respirations are $62/\text{min}$. On physical examination, the infant appears mottled and lethargic. The abdomen is markedly distended and tense, with sluggish bowel sounds. Digital rectal examination produces a sudden, high-pressure expulsion of liquid stool and gas. A plain abdominal radiograph demonstrates markedly dilated loops of bowel with multiple air-fluid levels, but no free air is visible under the diaphragm. Which of the following is the most appropriate next step in management?