Pediatrics

A $12$-day-old male infant is brought to the emergency department by his parents due to lethargy, poor feeding, and rapid breathing that started earlier today. He was born at $39$ weeks gestation via an uncomplicated spontaneous vaginal delivery and was discharged on day $2$ of life. The prenatal course was unremarkable. His temperature is $36.8^\circ\text{C}$ ($98.2^\circ\text{F}$), heart rate is $185/\text{min}$, respiratory rate is $72/\text{min}$, and oxygen saturation is $94\%$ on room air. Blood pressure is $75/45\text{ mmHg}$ in the right arm and $50/30\text{ mmHg}$ in the left leg. On physical examination, the infant appears pale and mottled. Capillary refill time is $4$ seconds. Brachial pulses are bounding, but femoral pulses are barely palpable bilaterally. A grade $2/6$ systolic ejection murmur is heard at the left sternal border. Lung auscultation reveals mild bilateral crackles. Arterial blood gas analysis shows a pH of $7.15$, $p\text{CO}_2$ of $32\text{ mmHg}$, and $\text{HCO}_3^-$ of $11\text{ mEq/L}$. Which of the following is the most appropriate initial pharmacological intervention for this patient?

Match each pediatric patient's clinical presentation with the correct underlying genetic or enzymatic defect.

An 8-year-old girl is referred to the pediatric endocrinology clinic for evaluation of growth failure. Her parents report that she is the shortest in her class and has not needed a larger shoe size or new clothing sizes in the past two years. Review of her growth chart shows a height that has crossed two major percentile lines downward over the last 30 months, currently resting below the 1st percentile. Her weight is tracking consistently at the 45th percentile. She has no history of headaches, visual changes, gastrointestinal symptoms, or cold intolerance. Physical examination is unremarkable, with normal visual fields and Tanner stage 1 pubertal development. Arrange the following diagnostic and management steps in the most appropriate chronological order for evaluating this patient's growth deceleration.

A 2-year-old boy with sickle cell disease (HbSS) is brought to the emergency department by his parents due to the sudden onset of severe lethargy, pallor, and abdominal swelling. His parents report that he was playing normally this morning but became progressively weak and poorly responsive over the past 3 hours. His temperature is 37.1°C (98.8°F), heart rate is 165/min, respiratory rate is 40/min, and blood pressure is 75/40 mm Hg. Physical examination reveals marked conjunctival pallor and a massively enlarged, firm spleen extending into the left lower quadrant. Laboratory studies show a hemoglobin of 3.8 g/dL, platelets of 80,000/mm³, and a reticulocyte count of 18%. What is the most appropriate next step in the management of this patient?

A 9-year-old girl is transported to the emergency department by ambulance due to severe respiratory distress. According to her parents, she has a history of moderate persistent asthma but exhausted her supply of inhaled corticosteroids two weeks ago. Yesterday, she developed a persistent cough and shortness of breath that did not respond to repeated doses of a short-acting bronchodilator. On evaluation, the patient appears exhausted, lethargic, and is leaning forward in a tripod position. Her temperature is $37.1^\circ \text{C}$ ($98.8^\circ \text{F}$), blood pressure is $112/68 \text{ mm Hg}$, heart rate is $152/\text{min}$, and respiratory rate is $44/\text{min}$. Pulse oximetry shows an oxygen saturation of $87\%$ on room air. Physical examination is notable for severe suprasternal and intercostal retractions. Auscultation reveals a "silent chest" with markedly diminished air entry bilaterally and no audible wheezing. An arterial blood gas on room air reveals a pH of $7.36$, a $\text{PaCO}_2$ of $44 \text{ mm Hg}$, and a $\text{PaO}_2$ of $58 \text{ mm Hg}$. Which of the following is the most appropriate next step in management?

A 7-month-old female infant is evaluated in the pediatric neurology clinic due to abnormal body movements that began two weeks ago. Her parents report that she experiences sudden, brief episodes where her neck, trunk, and arms flex symmetrically while her legs pull upward. These movements occur in clusters of 10 to 15, almost exclusively when she is waking up from her daytime naps. Before these episodes began, she was able to roll over and sit with support, but she now appears less interactive and no longer attempts to sit. Her prenatal history is notable for a fetal ultrasound that demonstrated a suspected cardiac mass, which was observed but required no postnatal surgical intervention. Her vital signs are within normal limits. Neurological examination reveals a socially disengaged infant with mild axial hypotonia. Wood's lamp examination of the skin reveals three 1-cm elliptical, hypopigmented macules on her lower back and left thigh. An electroencephalogram (EEG) demonstrates a chaotic, high-voltage background with multifocal spikes and slow waves. Which of the following is the most appropriate initial pharmacotherapy for this patient's current neurological condition?

A 5-day-old female neonate, born prematurely at 28 weeks gestation, is evaluated in the neonatal intensive care unit for increasing respiratory distress. Over the past 12 hours, she has developed worsening tachypnea and an increased need for supplemental oxygen. Vital signs show a heart rate of 168/min, respiratory rate of 72/min, and blood pressure of 55/25 mm Hg. Physical examination reveals bounding peripheral pulses in all four extremities and a hyperactive precordium. Cardiac auscultation demonstrates a prominent, continuous, "machine-like" murmur heard best at the left second intercostal space. Echocardiography confirms a patent vascular connection between the descending aorta and the main pulmonary artery with left-to-right shunting. Which of the following is the most appropriate initial pharmacologic intervention to close this defect?

A 12-day-old male infant is brought to the emergency department by his parents due to excessive vomiting, poor feeding, and lethargy over the past two days. He was born at term without complications and has been exclusively breastfed since birth. Physical examination reveals scleral icterus, diffuse jaundice, and a palpable liver edge 3 cm below the right costal margin. Ophthalmologic examination is notable for bilateral cataracts. Laboratory testing demonstrates hypoglycemia and elevated liver transaminases. Which of the following is the most appropriate next step in the management of this patient's condition?

A $5$-year-old boy is brought to the emergency department via ambulance in active status epilepticus. His parents report that he developed a high fever earlier in the day and subsequently began exhibiting generalized tonic-clonic movements that have now lasted for $7$ continuous minutes without cessation. Upon arrival, he remains unresponsive with ongoing rhythmic jerking of all four extremities. His temperature is $39.2^\circ\text{C}$ ($102.6^\circ\text{F}$), blood pressure is $105/65\text{ mmHg}$, pulse is $145/\text{min}$, and respiratory rate is $28/\text{min}$. The patient has no history of epilepsy. Assuming the seizure remains refractory to each sequential intervention, arrange the following management steps in the correct chronological order according to standard pediatric status epilepticus guidelines.

Match the following pediatric clinical vignettes with the most likely diagnosis.

Match each common pediatric congenital cardiovascular disorder with its classic physical examination finding.

Match each characteristic peripheral blood smear or microscopic finding with the most likely corresponding pediatric hematologic or oncologic diagnosis.

Match the following clinical presentations of pediatric limp and lower extremity pain with their most accurate underlying pathophysiologic description.

A 14-day-old term male infant is brought to the emergency department due to acute onset of irritability and three episodes of bright green emesis over the past 4 hours. The infant was born at 39 weeks gestation without complications and had been feeding well until today. Vital signs are within normal limits for age. Physical examination reveals a soft, non-distended abdomen without palpable masses, guarding, or erythema. There is no hemodynamic instability. Assuming this patient proceeds through standard evaluation and requires surgical intervention for the most likely underlying etiology without evidence of bowel perforation at any stage, arrange the following diagnostic and therapeutic steps in the correct chronological sequence.

Match each pediatric patient's clinical presentation with the most likely congenital cardiac anomaly.

A 4-week-old boy is brought to the emergency department by his parents due to a 3-day history of worsening vomiting. The parents report that he forcefully vomits a large amount of milk immediately after almost every feed. The vomitus does not contain bile. Despite the vomiting, the infant appears hungry and eagerly accepts feeds right after an episode. He has had only one wet diaper in the past 12 hours. Vital signs are temperature 37.0°C (98.6°F), heart rate 165/min, blood pressure 70/40 mm Hg, and respiratory rate 40/min. Physical examination reveals a sunken anterior fontanelle, dry mucous membranes, and markedly decreased skin turgor. Palpation of the abdomen reveals a firm, mobile, olive-shaped mass in the right upper quadrant. Laboratory studies are obtained and show the following:

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

An 8-year-old boy with a known history of moderate persistent asthma presents to the emergency department with acute, severe shortness of breath. He is visibly distressed, using accessory muscles to breathe, and speaking in fragmented sentences. Vital signs reveal a respiratory rate of 42 breaths/min and an oxygen saturation of 88% on room air. Auscultation demonstrates markedly diminished breath sounds with faint expiratory wheezing bilaterally. Arrange the following acute management steps in the most appropriate sequential order for this patient, from first to last.

A 3-year-old boy is brought to the pediatric neurology clinic by his mother and 14-year-old sister for a routine follow-up of his seizure disorder. He has a history of infantile spasms that have now evolved into focal impaired awareness seizures. Examination of the boy reveals erythematous, papular facial lesions clustered around the nose and a thickened, elevated plaque on his lumbosacral region.

During the developmental assessment, the mother expresses concern about the boy's progress. He can walk up steps with assistance and build a tower of six blocks, but he is unable to copy a cross or hop on one foot.

During the visit, the 14-year-old sister asks to speak to the physician privately. She requests a prescription for oral contraceptives, explicitly asking that her mother not be informed. Additionally, the sister complains of a mild cough, rhinorrhea, and sore throat that began 48 hours ago; her physical exam is consistent with an uncomplicated viral upper respiratory infection, yet she asks for a strong antibiotic to "knock it out quickly."

Which of the following statements regarding the management and clinical evaluation of these patients are correct? (Select all that apply)

During a routine kindergarten physical, the physician notes that a 5-year-old boy has grown significantly faster than his peers. His parents report that he has developed axillary hair and adult-like body odor over the last six months. He is otherwise healthy and takes no medications. Vital signs show a blood pressure of $134/86\text{ mm Hg}$ (greater than the 99th percentile for his age and height). Physical examination reveals a muscular habitus and moderate facial acne. Genitourinary examination demonstrates Tanner stage III pubic hair, an enlarged phallus, and bilateral testicular volumes of $2\text{ mL}$. Radiographic imaging of the left wrist indicates a bone age of 9 years, and his serum testosterone is markedly elevated. Which of the following laboratory abnormalities is most likely to be found in this patient?

A 4-year-old boy is brought to the pediatrician's office by his parents after they noticed a red, pinpoint rash on his legs and arms this morning. The patient had a mild upper respiratory tract infection two weeks ago but has completely recovered. He is currently active and well-appearing. His temperature is 37.0°C (98.6°F), blood pressure is 95/60 mmHg, pulse is 90/min, and respirations are 20/min. Physical examination reveals scattered petechiae and purpura over the lower extremities. There is no hepatosplenomegaly, lymphadenopathy, or joint swelling. Laboratory evaluation shows:

Hemoglobin: 12.2 g/dL
Leukocyte count: 7,500/mm³
Platelet count: 15,000/mm³
Prothrombin time: 11 seconds (normal: 11-15 seconds)
Activated partial thromboplastin time: 30 seconds (normal: 25-40 seconds)

Which of the following is the most likely diagnosis?