Pediatric Gastrointestinal Disorders

A 1-month-old boy is evaluated in the pediatric emergency department due to a 4-day history of progressively forceful vomiting. The parents report that he eagerly feeds but regurgitates the entire volume immediately afterward. The vomitus consists of undigested milk and does not appear green. The infant has not had a bowel movement in two days and is producing fewer wet diapers. Vital signs show a heart rate of $170/\text{min}$, respiratory rate of $35/\text{min}$, and blood pressure of $75/45 \text{ mm Hg}$. Physical examination reveals a lethargic infant with a sunken anterior fontanelle, dry mucous membranes, and delayed capillary refill. Palpation of the abdomen reveals a $2\text{-cm}$, firm, mobile mass in the right epigastrium. Laboratory studies reveal a pH of $7.52$, serum sodium of $132 \text{ mEq/L}$, potassium of $2.9 \text{ mEq/L}$, and chloride of $88 \text{ mEq/L}$. What is the most appropriate next step in the management of this patient?

A 2-week-old full-term female infant is brought to the emergency department due to a 12-hour history of persistent bilious vomiting. The parents report that she has become increasingly lethargic and has not had a wet diaper in the past 18 hours. On physical examination, her temperature is 37.6°C (99.7°F), heart rate is 185/min, respiratory rate is 55/min, and blood pressure is 55/35 mm Hg. The abdomen is notably distended and rigid to palpation with involuntary guarding. Bowel sounds are absent. Capillary refill is delayed at 4 seconds. An upright abdominal X-ray reveals a paucity of distal bowel gas. Following initial fluid resuscitation, what is the most appropriate next step in management?

Match each classic pediatric gastrointestinal clinical presentation to its most appropriate definitive management or next best therapeutic step.

A primigravid mother rushes her 12-day-old male newborn to the acute care clinic because he has been persistently vomiting a bright green substance since the morning. The pregnancy and delivery were entirely normal. The mother mentions the infant is usually calm but has been inconsolably fussy and repeatedly drawing his legs up toward his chest. Upon triage assessment, the infant is lethargic with a heart rate of 188/min, respiratory rate of 58/min, and a palpable systolic blood pressure of only 55 mm Hg. Capillary refill time is prolonged at 4 seconds. The abdominal examination is notable for a tense, distended contour with involuntary guarding and absent auscultatory bowel activity. Intravenous access is rapidly secured, and a bolus of normal saline is administered. A bedside abdominal X-ray displays minimal gas in the distal intestine without free intraperitoneal air. Which of the following is the most appropriate next step in the management of this patient?

Paramedics arrive at the emergency department with a 4-week-old infant who is lethargic and feverish. The infant's parents report a 12-hour history of explosive, foul-smelling diarrhea and progressive abdominal swelling. Medical history is notable for delayed meconium passage after birth, which required a glycerin suppository. Vital signs show a temperature of $39.2^\circ\text{C}$ ($102.6^\circ\text{F}$), a heart rate of $185\text{/min}$, a respiratory rate of $60\text{/min}$, and a blood pressure of $58/30\text{ mm Hg}$. The capillary refill time is 4 seconds. On physical examination, the infant is poorly responsive and has a markedly distended, tense abdomen. The clinical picture is highly suspicious for Hirschsprung-associated enterocolitis complicated by septic shock.

Arrange the following management steps in the most appropriate chronological sequence for this patient's immediate care.

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.

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

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?

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

A first-time mother brings her $4$-week-old boy to the acute care clinic because he has been forcefully vomiting after every meal for the last $48$ hours. The vomit does not contain bile. She notes that he appears extremely hungry and eagerly attempts to feed again immediately after these episodes. Vital signs reveal a heart rate of $162 \text{ beats/min}$ and a respiratory rate of $32 \text{ breaths/min}$. On physical examination, the infant has dry mucous membranes, a sunken anterior fontanelle, and delayed capillary refill. Careful abdominal palpation reveals a firm, olive-shaped mass in the right upper quadrant.

Laboratory analysis demonstrates:

Which of the following represents the most appropriate initial step in the care of this patient?

A $10$-month-old female infant is brought to the emergency department by her parents due to severe, episodic abdominal pain and lethargy. The parents report she has been pulling her legs up to her chest and crying inconsolably for the past $24$ hours. In the last $4$ hours, she has become increasingly difficult to arouse. She recently passed a stool described by the parents as looking like "currant jelly."

Physical examination reveals:
Temperature: $38.7^\circ\text{C}$ ($101.7^\circ\text{F}$)
Heart rate: $185/\text{min}$
Respiratory rate: $55/\text{min}$
Blood pressure: $65/40\text{ mmHg}$

The infant appears toxic, mottled, and lethargic. The abdomen is grossly distended, rigid, and exquisitely tender to light palpation. Bowel sounds are absent.

Laboratory results:
pH: $7.24$
PaCO $_2$: $30\text{ mmHg}$
HCO $_3^-$: $12\text{ mEq/L}$
Lactate: $5.8\text{ mmol/L}$ (Normal: $0.5-1.5$)

After initiating airway management and aggressive intravenous fluid resuscitation, which of the following is the most appropriate next step in the management of this patient?

A $3$-year-old boy is brought to the pediatric emergency department due to sudden onset of severe, colicky abdominal pain that began $12$ hours ago. Initially, the pain was intermittent, but it has now become constant. He has vomited bilious material four times in the past $6$ hours. The parents report that over the last month, the child had two episodes of painless, dark red rectal bleeding, which resolved spontaneously. On physical examination, the child appears lethargic and toxic. Temperature is $39.1^\circ\text{C}$ ($102.4^\circ\text{F}$), pulse is $160/\text{min}$, respirations are $32/\text{min}$, and blood pressure is $75/40\text{ mmHg}$. Abdominal examination reveals a rigid, distended abdomen with diffuse guarding, rebound tenderness, and a palpable sausage-shaped mass in the right mid-abdomen. Laboratory studies show:

Following initial fluid resuscitation, 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 noticed a large amount of maroon-colored stool in his diaper this morning. He has had one additional bloody bowel movement since arrival. The parents report that the child has been completely asymptomatic otherwise; he has had no fever, vomiting, diarrhea, or apparent abdominal pain, and his appetite has been normal. He has no significant past medical history and has met all developmental milestones. Vital signs are temperature $37.1^\circ$ C ($98.8^\circ$ F), blood pressure $95/60$ mm Hg, pulse $115$/min, and respiratory rate $22$/min. Physical examination reveals an alert and playful child. The abdomen is soft, non-distended, and non-tender to palpation, with no palpable masses. Laboratory studies show a hemoglobin level of $10.4$ g/dL and a platelet count of $250,000$/mm $^3$. Which of the following is the most appropriate next step in the diagnostic evaluation of this patient?

A 14-year-old girl is hospitalized for an acute, severe exacerbation of newly diagnosed ulcerative colitis. Over the past 48 hours, she has been treated with intravenous fluids, methylprednisolone, and prophylactic low-molecular-weight heparin. The nursing staff urgently calls the physician to the bedside due to an abrupt deterioration in her clinical status. The patient reports continuous, excruciating abdominal pain that is no longer crampy. Her temperature is 39.4°C (102.9°F), blood pressure is 84/50 mmHg, heart rate is 142/min, and respiratory rate is 28/min. Physical examination demonstrates a markedly distended, tympanitic abdomen with diffuse rigidity, guarding, and rebound tenderness. Bowel sounds are absent. A portable supine abdominal radiograph reveals a transverse colon diameter of 7.5 cm, loss of normal haustral markings, and mucosal edema, with no free intraperitoneal air.

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

A 2-day-old male neonate is evaluated in the neonatal intensive care unit after two episodes of bilious emesis. He was born at 38 weeks gestation via uncomplicated spontaneous vaginal delivery to a 29-year-old primigravida. Prenatal ultrasonography at 32 weeks revealed polyhydramnios. His temperature is 37.1°C (98.8°F), heart rate is 145/min, blood pressure is 65/40 mm Hg, and respiratory rate is 42/min. Physical examination reveals a soft, non-distended abdomen without guarding, rigidity, or erythema of the abdominal wall. Bowel sounds are decreased. A nasogastric tube is placed, returning 25 mL of dark green fluid. An anteroposterior abdominal radiograph demonstrates a distended stomach and proximal duodenum (double bubble sign), along with a small amount of scattered gas in the distal small and large bowels. There is no pneumatosis intestinalis or free intraperitoneal air. Which of the following is the most appropriate next step in management?

An 8-month-old female infant is brought to the pediatric emergency department due to sudden episodes of severe, inconsolable crying. During these episodes, she draws her knees to her chest. The episodes began 24 hours ago and have progressively worsened in frequency. Earlier today, she began having non-bilious vomiting, which recently transitioned to bilious emesis. Her last bowel movement contained dark red blood and thick mucus.

On physical examination, her temperature is 38.8°C (101.8°F), heart rate is 175/min, respiratory rate is 45/min, and blood pressure is 68/40 mmHg. She appears lethargic and pale. Abdominal examination reveals a rigid, distended abdomen with severe, diffuse tenderness and involuntary guarding. Bowel sounds are absent. Arterial blood gas analysis demonstrates a $pH$ of 7.24, $pCO_2$ of 28 mmHg, and $HCO_3^-$ of 12 mEq/L.

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

A 28-day-old male infant is urgently evaluated in the emergency department after his parents noted a sudden onset of inconsolable crying and repeated episodes of vomiting over the past 5 hours. The vomitus was initially composed of digested breast milk but has recently become dark green. He was born at 38 weeks gestation without complications and had been feeding well until this morning. On physical examination, the infant appears mottled and lethargic. Vital signs reveal a temperature of 38.1°C (100.6°F), heart rate of 192/min, respiratory rate of 65/min with intercostal retractions, and blood pressure of 54/32 mm Hg. Capillary refill time is prolonged at 6 seconds. The abdomen is distended, markedly rigid, and exquisitely tender to palpation, with a faint erythematous discoloration of the periumbilical skin. Bowel sounds are absent. A portable plain radiograph of the abdomen demonstrates a paucity of distal bowel gas with no evidence of pneumoperitoneum. Which of the following is the most appropriate next step in the management of this patient?

Match each pediatric patient's clinical vignette (left) with the underlying pathophysiological or embryological mechanism responsible for the condition (right).

A 6-year-old boy is brought to the emergency department by his parents due to severe, intermittent abdominal pain that began 12 hours ago. During the episodes, the patient cries out and pulls his knees to his chest. He has also had two episodes of non-bilious vomiting. Over the past week, the parents noted a low-grade fever, bilateral ankle swelling, and a bumpy, reddish-purple rash on his buttocks and posterior thighs that does not disappear when pressure is applied. Today, he passed a stool containing dark red blood and mucus. Vital signs are temperature 37.8°C (100.0°F), heart rate 118/min, and blood pressure 105/65 mmHg. Abdominal examination reveals diffuse tenderness and a palpable, sausage-shaped fullness in the right middle quadrant. A point-of-care abdominal ultrasound shows a multi-layered, alternating echogenic and hypoechoic concentric ring mass in the right abdomen. Which of the following best describes the underlying pathogenesis of the focal abnormality that directly triggered this patient's acute gastrointestinal complication?