Pediatrics

A 2-month-old male infant is brought to the clinic for evaluation of frequent, forceful regurgitation after almost every feed. His parents report that he frequently arches his back, cries during feedings, and seems generally irritable. Review of his growth chart shows he has dropped from the 50th percentile for weight at birth to the 10th percentile currently. Physical examination is unremarkable, with a soft, non-tender abdomen and normal bowel sounds. There are no signs of acute infection. Arrange the following steps in the most appropriate sequential order for the evaluation and management of this patient's condition, from the initial intervention to the final option for severe, refractory disease.

A $4$-year-old boy is evaluated in the pediatric oncology clinic for an urgent follow-up. He was diagnosed with standard-risk B-cell acute lymphoblastic leukemia (ALL) eight months ago and is currently in the maintenance phase of chemotherapy. Today, he has mild rhinorrhea but is otherwise active and playful. His mother reports that the patient spent the weekend with his $6$-year-old cousin. Three days after the exposure, the cousin developed a low-grade fever and a diffuse vesicular rash that was subsequently diagnosed as chickenpox by a pediatrician. The patient has never had chickenpox and missed his routine preschool immunizations due to his cancer diagnosis. The patient's temperature is $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), blood pressure is $95/60 \text{ mmHg}$, heart rate is $100/\text{min}$, and respiratory rate is $20/\text{min}$. Physical examination reveals clear lungs, normal heart sounds, and no skin lesions. Laboratory studies show a leukocyte count of $3,200/\text{mm}^3$ with an absolute neutrophil count of $1,600/\text{mm}^3$. The mother asks how to protect her son from the exposure. Which of the following is the most appropriate next step in management?

A 3-year-old boy is brought to the pediatrician by his parents due to worsening behavioral outbursts and a decline in his communication skills. Over the past year, he has stopped using two-word phrases and has become increasingly hyperactive and aggressive. The parents also report that he has "noisy breathing," chronic nasal discharge, and recurrent wheezing that has not improved with multiple trials of inhaled albuterol. His medical history is notable for bilateral inguinal hernia repairs at age 1. Vital signs are within normal limits. Physical examination reveals a macrocephalic child with prominent supraorbital ridges, a broad nose, and a large tongue. Abdominal examination demonstrates a firm liver edge 4 cm below the right costal margin and a palpable splenic tip. Skin examination reveals distinct, grouped, ivory-colored papules over the scapular region. Slit-lamp examination of the eyes shows perfectly clear corneas. Laboratory studies show a serum thyroid-stimulating hormone (TSH) of 2.1 µU/mL (normal: 0.5–5.0 µU/mL). Which of the following is the most likely underlying etiology of this patient's condition?

Match each pediatric gastrointestinal emergency clinical presentation with its most appropriate definitive surgical management.

A $7$-year-old male child presents to the outpatient clinic accompanied by his mother due to an altered gait that began approximately $8$ weeks ago. The mother describes a progressive limp that worsens towards the end of the day. The child occasionally mentions mild aching in his left groin and distal anterior thigh. He has not had any recent infections, and there is no history of preceding trauma. Vital signs show a temperature of $37.1^\circ\text{C}$ ($98.8^\circ\text{F}$), pulse of $84/\text{min}$, and blood pressure of $102/64\text{ mm Hg}$. On physical examination, the patient has a noticeable Trendelenburg gait. Inspection reveals $1\text{ cm}$ of muscle atrophy in the left quadriceps compared to the right. When the patient is supine, the left hip exhibits limited abduction and restricted internal rotation. Examination of the left knee reveals no swelling, erythema, or pain with movement. Laboratory analysis demonstrates a leukocyte count of $7,200/\text{mm}^3$, an erythrocyte sedimentation rate of $10\text{ mm/h}$, and a C-reactive protein of $2.0\text{ mg/L}$. Which of the following is the most appropriate initial step in the evaluation of this patient?

A 6-year-old boy is newly diagnosed with Burkitt lymphoma. He presents with a large abdominal mass, and laboratory studies reveal a significantly elevated serum lactate dehydrogenase (LDH) and uric acid level. The oncology team is preparing to begin his treatment but must first address his high risk for developing tumor lysis syndrome (TLS). Arrange the following management steps in the most appropriate sequential order, starting from the most critical initial preventive measure to the intervention reserved for severe, refractory complications.

An 8-year-old girl is evaluated in the emergency department due to rapidly worsening shortness of breath. She has a known history of moderate persistent asthma. Two days ago, she developed rhinorrhea, a mild cough, and a low-grade fever. Over the past hour in the emergency department, she has received three consecutive nebulized albuterol-ipratropium treatments and a dose of intravenous methylprednisolone, but her work of breathing continues to increase. She is up to date on all childhood immunizations. Vital signs show a temperature of $37.4^\circ\text{C}$ ($99.3^\circ\text{F}$), a heart rate of $152/\text{min}$, a respiratory rate of $44/\text{min}$, and an oxygen saturation of $89\%$ on $4\text{ L/min}$ supplemental oxygen via nasal cannula. On physical examination, she is diaphoretic, visibly fatigued, and sitting forward. There are prominent supraclavicular and intercostal retractions. Lung auscultation reveals markedly diminished air entry bilaterally without audible wheezing. Which of the following interventions are indicated as part of the immediate management bundle for this patient? (Select all that apply)

Match each clinical vignette describing a neonate with a congenital infection to the most likely causative pathogen.

A $6$-day-old term neonate is brought to the pediatric emergency department presenting with progressive lethargy, a weak suck, and recurrent emesis over the past $24$ hours. On physical examination, the infant is hypotonic, difficult to arouse, and exhibits deep, rapid respirations. Initial laboratory studies reveal a severe high anion gap metabolic acidosis, significant ketonuria, and a plasma ammonia level of $320 \mu\text{mol/L}$ (normal: $10-50 \mu\text{mol/L}$). The clinical picture is highly suspicious for an acute metabolic crisis secondary to an underlying organic acidemia.

Arrange the following management and diagnostic steps in the most appropriate, chronologically prioritized sequence for this patient.

A $14$-month-old girl is brought to the emergency department due to progressive lethargy, vomiting, and rapid breathing over the past $24$ hours. Two days ago, she developed a mild viral upper respiratory tract infection. Her parents report that she had been developing normally until $8$ months of age, but she subsequently lost the ability to sit unsupported and no longer babbles. Vital signs reveal a temperature of $37.6^\circ\text{C}$ ($99.7^\circ\text{F}$), heart rate of $165/\text{min}$, respiratory rate of $55/\text{min}$, and blood pressure of $80/40\text{ mm Hg}$. Physical examination is notable for marked hypotonia, diminished deep tendon reflexes, and deep, rapid, unlabored respirations without wheezing or crackles.

Laboratory studies show:
* Sodium: $138\text{ mEq/L}$
* Potassium: $4.8\text{ mEq/L}$
* Chloride: $102\text{ mEq/L}$
* Bicarbonate: $10\text{ mEq/L}$
* Blood glucose: $45\text{ mg/dL}$
* Blood urea nitrogen: $18\text{ mg/dL}$
* Creatinine: $0.4\text{ mg/dL}$

Arterial blood gas (room air):
* pH: $7.15$
* **PaCO $_2$**: $28\text{ mm Hg}$
* **PaO $_2$**: $98\text{ mm Hg}$

Urine organic acid analysis demonstrates massively elevated levels of methylmalonic acid.

Which of the following statements regarding this patient's condition and clinical presentation is most accurate?

During a routine follow-up visit, the parents of a 40-day-old infant report an alarming pattern of vomiting that began one week ago. They describe the vomiting as projectile, occurring 10 to 15 minutes after breastfeeding. The vomitus consists solely of undigested milk. Despite the frequent vomiting, the infant exhibits a strong appetite and eagerly attempts to feed again. Upon review of systems, the parents note the infant has had only one wet diaper in the past 24 hours. Vital signs in the clinic show a heart rate of 180/min, a respiratory rate of 32/min, and a blood pressure of 68/38 mm Hg. Physical examination reveals lethargy, a sunken anterior fontanelle, dry oral mucosa, and poor skin turgor. A firm, movable, 2-cm mass is palpated in the right epigastric region. Stat laboratory testing demonstrates the following:

What is the most appropriate initial step in managing this patient's condition?

A 5-week-old male infant is evaluated in the emergency department for persistent vomiting over the past 5 days. His parents report that he forcefully vomits large amounts of milk immediately after every feed. The vomitus does not contain bile or blood. Despite the frequent vomiting, the infant appears extremely hungry and eagerly feeds when offered. He has had only one wet diaper in the last 24 hours. He was born at full term via uncomplicated vaginal delivery. Vital signs show a heart rate of $168 \text{ /min}$, respiratory rate of $30 \text{ /min}$, and blood pressure of $72/40 \text{ mm Hg}$. Physical examination reveals a lethargic infant with sunken eyes, dry mucous membranes, and a depressed anterior fontanelle. Palpation of the abdomen reveals a firm, mobile, $2 \text{-cm}$ mass in the right upper quadrant.

Laboratory studies show:
Sodium: $131 \text{ mEq/L}$
Potassium: $2.8 \text{ mEq/L}$
Chloride: $85 \text{ mEq/L}$
Bicarbonate: $35 \text{ mEq/L}$
Blood urea nitrogen (BUN): $34 \text{ mg/dL}$
Creatinine: $0.8 \text{ mg/dL}$

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

A 4-week-old male infant is brought to the pediatric clinic by his first-time parents who are concerned about multiple symptoms. They report that he "spits up" approximately one to two tablespoons of uncurdled milk after nearly every feed, although he feeds eagerly and does not appear irritable. The parents also noted a "terrible rash" that appeared on his face a week ago. Furthermore, they are worried because his hands remain tightly fisted, he does not yet reach for objects, and his breathing occasionally sounds noisy and raspy when he is crying. The infant was born at 39 weeks gestation via an uncomplicated vaginal delivery. His weight has increased from 3.2 kg (7 lb 1 oz) at birth to 4.1 kg (9 lb). Current vital signs show a rectal temperature of 37.5°C (99.5°F), heart rate of 145/min, and respiratory rate of 40/min. Physical examination reveals multiple erythematous papules and pustules confined to the cheeks and forehead without a surrounding erythematous base. Lung auscultation is clear with no retractions, and the cardiac examination is unremarkable. Which of the following is the most appropriate next step in management?

An 11-year-old boy is brought to the pediatric emergency department due to severe, worsening shortness of breath over the past 24 hours. He has a known history of moderate persistent asthma and has been using his albuterol inhaler every 2 hours at home without relief. On arrival, the patient appears lethargic and diaphoretic. He is only able to speak in single syllables. His temperature is $37.2^\circ\text{C}$ ($99.0^\circ\text{F}$), pulse is $155/\text{min}$, respirations are $14/\text{min}$, and blood pressure is $112/68\text{ mm Hg}$. Pulse oximetry is $87\%$ on room air. Lung auscultation reveals a "silent chest" with profoundly diminished air entry bilaterally and minimal wheezing.

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

A 15-month-old male toddler is evaluated in the pediatric emergency center due to worsening respiratory effort and poor oral intake over the last 24 hours. The parents note that he developed a profuse runny nose, mild fever, and a paroxysmal cough three days ago. His birth history is notable for delivery at 34 weeks gestation. He has no history of atopy or prior wheezing episodes. On physical examination, the patient's temperature is $38.2^\circ\text{C}$ ($100.8^\circ\text{F}$), heart rate is $165/\text{min}$, respiratory rate is $72/\text{min}$, and oxygen saturation is $87\%$ on room air. The child appears lethargic but is easily arousable. He exhibits pronounced nasal flaring, intercostal retractions, and expiratory grunting. Auscultation of the chest reveals widespread coarse crackles and high-pitched expiratory polyphonic wheezing. Which of the following interventions are indicated as part of the most appropriate management bundle for this patient? (Select all that apply)

Correlate the following pediatric clinical vignettes with their most likely underlying embryologic or pathophysiologic etiology.

A 3-year-old girl is brought to the pediatrician by her parents for a routine well-child visit. The parents express concern that she might be experiencing developmental delays compared to her older brother at this age. They report that she cannot yet catch a bounced ball, hop on one foot, or draw a person. Furthermore, while she frequently speaks in three-word sentences, strangers can only understand her about 75% of the time, and she is unable to tell a cohesive story. Currently, the patient can safely ride a tricycle, alternate her feet when walking up a flight of stairs, copy a circle, and feed herself with a fork. She knows her age and gender and frequently engages in imaginative play. Vital signs are within normal limits. Physical examination reveals normal muscle tone, intact reflexes, and no dysmorphic features. Which of the following is the most appropriate next step in management?

A 36-month-old boy is brought to the clinic for a routine well-child evaluation. His parents express concern regarding his development, specifically noting that he frequently talks to an "invisible dinosaur" in his bedroom. They also report that he refuses to share toys with his peers at daycare, often snatching items away from other children during playtime. Furthermore, the parents mention that while they understand most of his speech, his daycare teachers and extended family members can only understand about 75% of what he says. The patient has no significant past medical history. On physical examination, the child is active and cooperative. He speaks in three-word sentences, successfully pedals a tricycle down the clinic hallway, copies a circle drawn by the physician, and builds a tower of 9 blocks. Which of the following is the most appropriate next step in management?

Match the following developmental milestones, clinical red flags, and pubertal changes to their corresponding expected age thresholds or clinical classifications.

A healthy two-year-old boy presents to the outpatient clinic with his father for a routine health maintenance evaluation. The father reports that the child is active, eats a balanced diet, and sleeps well through the night. On observation, the toddler easily kicks a ball, climbs onto the examination table, and stacks a set of six wooden blocks. When evaluating this patient's speech and language progression, which of the following findings is the most age-appropriate expectation?