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Pediatric Gastrointestinal Disorders

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Question 81Question →

A 44-year-old girl is brought to the pediatric clinic by her mother due to a 66-month history of foul-smelling, bulky stools and poor weight gain. Her mother reports that the child frequently complains of diffuse abdominal discomfort and has become increasingly irritable. The patient's growth chart indicates that her weight has dropped from the 50th50^{\text{th}} percentile to the 10th10^{\text{th}} percentile over the past year, while her height remains tracking at the 40th40^{\text{th}} percentile. Physical examination reveals a visibly distended abdomen and decreased subcutaneous fat in the extremities. Laboratory evaluation demonstrates a hemoglobin of 9.2 g/dL9.2 \text{ g/dL} with a mean corpuscular volume of 72 fL72 \text{ fL}. Which of the following is the most appropriate initial diagnostic step for this patient?

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Answer: Measurement of serum tissue transglutaminase IgA antibodies

Answer

Measurement of serum tissue transglutaminase IgA antibodies is the best first step.
This patient's presentation of chronic, bulky, foul-smelling stools, failure to thrive (evidenced by her weight dropping multiple major percentiles), abdominal distension, and microcytic anemia is highly suspicious for celiac disease. The initial non-invasive test of choice for suspected celiac disease is the measurement of serum tissue transglutaminase (tTG) IgA antibodies. This test has excellent sensitivity and specificity. It is typically drawn alongside a total serum IgA level to ensure the patient does not have a concurrent selective IgA deficiency, which could cause a false-negative result.

Step-by-Step Solution

1
Analyze the clinical presentation and physical exam findings.
The patient has chronic malabsorptive diarrhea, severe failure to thrive (falling percentiles), and abdominal distension.
These are classic signs of a small bowel mucosal disorder, leading to nutrient malabsorption.
2
Evaluate the laboratory results.
Hemoglobin of 9.2 g/dL and MCV of 72 fL indicate a microcytic anemia.
Microcytic anemia in this context is likely secondary to iron malabsorption in the damaged duodenum, highly characteristic of celiac disease.
3
Determine the appropriate initial diagnostic pathway.
Select non-invasive serologic screening with tissue transglutaminase (tTG) IgA antibodies.
Current guidelines require a highly sensitive serologic test before proceeding to invasive confirmatory procedures like endoscopy.

Key Concept

The initial non-invasive screening step for celiac disease is testing for serum tissue transglutaminase IgA antibodies.
Question 82Question →

A 2-hour-old term male newborn is evaluated in the neonatal nursery for excessive drooling, frothy oral secretions, and episodes of choking and coughing accompanied by perioral cyanosis immediately upon his first feeding. The infant is currently breathing comfortably on room air after the feeding was abruptly stopped. Prenatal ultrasound was notable for severe polyhydramnios. Physical examination is unremarkable except for the continuous reaccumulation of copious oral secretions. Arrange the following steps in the most appropriate chronological order for the acute management and evaluation of this patient.

Drag items to arrange them in the correct order

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Answer

The correct sequence is to first make the patient NPO and elevate the head of the bed, followed immediately by inserting a suctioning orogastric tube. Once the airway is protected from secretions, obtain chest and abdominal radiographs to confirm the diagnosis, then perform a preoperative echocardiogram, and finally proceed with definitive surgical repair.
The management of esophageal atresia with tracheoesophageal fistula follows a strict protocol prioritizing airway protection. Making the infant NPO and elevating the head of the bed passively reduces aspiration, while placing an orogastric tube to continuous suction actively clears the blind pouch. Only after the airway is secured should diagnostic imaging (plain radiographs) be obtained. Once confirmed, preoperative workup for VACTERL anomalies (specifically echocardiography to check aortic arch laterality) must precede definitive surgical repair.

Step-by-Step Solution

1
Initiate strict NPO status and elevate the head of the bed.
Minimizes aspiration risk from pooled secretions and reduces gastric reflux through the fistula.
Immediate airway protection and aspiration prevention is the first step in any patient presenting with choking and copious secretions.
2
Insert an orogastric tube and apply continuous suction.
Actively clears saliva from the blind esophageal pouch.
Passive positioning is insufficient; active suctioning of the proximal pouch is required to prevent overflow aspiration into the trachea.
3
Obtain chest and abdominal radiographs.
Visualizes a coiled radiopaque tube in the upper chest and confirms distal bowel gas.
Confirms the diagnosis of esophageal atresia (coiled tube) and tracheoesophageal fistula (distal gas) without the need for high-risk contrast.
4
Perform a screening echocardiogram.
Evaluates for structural heart defects and determines the position of the aortic arch.
Over 50% of these infants have VACTERL anomalies. A right-sided aortic arch requires a left thoracotomy approach, making pre-operative echocardiography mandatory.
5
Proceed with surgical repair.
Definitive ligation of the fistula and anastomosis of the esophagus.
Surgery is the ultimate curative step once the patient is stabilized, diagnosed, and fully evaluated for complicating anatomical variations.

Key Concept

Management sequence of Esophageal Atresia with Tracheoesophageal Fistula (EA/TEF)
Estimated Time:1m 15s
Question 83Question →

Parents bring their 44-week-old male infant to the acute care clinic because he has been forcefully vomiting after feeds for the past five days. The nonbilious vomitus frequently shoots across the crib. Despite the recurrent emesis, the infant appears remarkably hungry and demands to feed again immediately. Over the last 4848 hours, his urine output has decreased to only one wet diaper per day. Vital signs show a heart rate of 165/min165\text{/min}, blood pressure of 68/38 mm Hg68/38\text{ mm Hg}, and respiratory rate of 32/min32\text{/min}. Physical examination reveals a lethargic infant with sunken eyes, a depressed anterior fontanelle, and a capillary refill time of 55 seconds. Abdominal examination is notable for a palpable, firm, olive-shaped mass in the right upper quadrant.

Laboratory studies demonstrate the following:

Laboratory TestResultReference Range
Sodium131 mEq/L131\text{ mEq/L}135−145 mEq/L135 - 145\text{ mEq/L}
Potassium2.8 mEq/L2.8\text{ mEq/L}3.5−5.0 mEq/L3.5 - 5.0\text{ mEq/L}
Chloride85 mEq/L85\text{ mEq/L}98−106 mEq/L98 - 106\text{ mEq/L}
Bicarbonate35 mEq/L35\text{ mEq/L}22−28 mEq/L22 - 28\text{ mEq/L}
Blood urea nitrogen32 mg/dL32\text{ mg/dL}5−18 mg/dL5 - 18\text{ mg/dL}
Creatinine0.7 mg/dL0.7\text{ mg/dL}0.2−0.4 mg/dL0.2 - 0.4\text{ mg/dL}

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

Show answer & explanation

Answer: Administration of an intravenous normal saline bolus

Answer

Administration of an intravenous normal saline bolus
The most appropriate initial step in the management of this patient is the administration of an intravenous normal saline bolus. This infant presents with the classic triad of hypertrophic pyloric stenosis: projectile nonbilious vomiting, a palpable olive-shaped abdominal mass, and visible gastric peristalsis (often seen in hungry infants). The profound vomiting of gastric contents (hydrochloric acid) results in a hypochloremic, hypokalemic metabolic alkalosis. This infant is hemodynamically unstable, exhibiting tachycardia, hypotension, lethargy, and a prolonged capillary refill time indicative of hypovolemic shock. According to pediatric advanced life support guidelines, the immediate priority in a patient with decompensated hypovolemic shock is rapid restoration of intravascular volume using an isotonic crystalloid, such as 0.9%0.9\% normal saline. Only after the patient's intravascular volume is restored and urine output is established should maintenance fluids with added potassium be initiated. Pyloromyotomy is the definitive treatment, but it is considered an elective procedure that must be delayed until the patient's acid-base status and electrolyte derangements are fully corrected.

Step-by-Step Solution

1
Identify the primary diagnosis based on the clinical presentation and physical exam.
The infant has hypertrophic pyloric stenosis, characterized by projectile nonbilious vomiting, an 'olive-shaped' abdominal mass, and an eagerness to feed.
Recognizing the classic triad of symptoms is essential for guiding subsequent workup and management.
2
Analyze the laboratory data and vital signs to determine the patient's physiological state.
The patient has severe hypovolemia (tachycardia, hypotension, prolonged capillary refill, elevated BUN/creatinine) and classic hypochloremic, hypokalemic metabolic alkalosis.
Prolonged vomiting of gastric acid leads to depletion of fluid, hydrogen, and chloride ions. The kidneys compensate by excreting potassium to retain hydrogen, worsening the hypokalemia.
3
Select the most appropriate immediate intervention based on acuity.
The patient requires immediate fluid resuscitation with an isotonic crystalloid solution (normal saline).
In any hemodynamically unstable patient, restoring intravascular volume and organ perfusion takes absolute precedence over definitive surgical treatment or imaging.

Key Concept

Medical optimization of hypertrophic pyloric stenosis prior to surgery
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