5.1 Pediatric GI Surgical Emergencies

5.1 Pediatric GI Surgical Emergencies

Gastrointestinal emergencies in pediatric patients demand rapid triage, systematic abdominal assessment, and immediate recognition of life-threatening conditions requiring emergency surgical consultation. Because infants and young children possess limited physiological reserve, delayed diagnosis of conditions such as midgut volvulus or bowel ischemia can lead to catastrophic short bowel syndrome, septic shock, or death.

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1. Hypertrophic Pyloric Stenosis (HPS)

Hypertrophic Pyloric Stenosis (HPS) is caused by progressive hypertrophy and hyperplasia of the circular muscle layer of the pyloric sphincter, resulting in complete or partial gastric outlet obstruction.

Epidemiology & Pathophysiology

• Peak Age of Onset: Typically presents between 2 and 8 weeks of age (peak incidence at 3 to 5 weeks). It is rare after 12 weeks of age.
• Demographics: Strong male predominance (4:1 male-to-female ratio), with first-born males having the highest statistical risk.
• Pathophysiology: Gastric outflow tract obstruction prevents gastric emptying, leading to severe vomiting, loss of gastric hydrochloric acid (HCl), sodium, and potassium, resulting in a classic metabolic derangement.

Clinical Presentation & Physical Examination Findings

• Non-Bilious Projectile Vomiting: The hallmark symptom is immediate postprandial, non-bilious projectile vomiting. The vomitus contains gastric contents and curdled milk but never bile because the obstruction is proximal to the ampulla of Vater.
• Persistent Hunger ("Hungry Vomiter"): Following emesis, the infant is immediately hungry, eager to feed, and exhibits vigorous rooting and sucking reflexes until severe dehydration and lethargy set in.
• Palpable "Olive" Mass: Pathognomonic physical exam finding is a firm, mobile, non-tender, olive-shaped mass approximately 1 to 2 cm in size located in the right upper quadrant (RUQ) or epigastrium, best palpated after emesis or NG decompression when the stomach is empty.
• Visible Peristaltic Waves: Peristaltic waves moving from left to right across the epigastrium may be observed immediately before projectile emesis.

Laboratory & Diagnostic Evaluation

• Electrolyte & Acid-Base Derangement: Hypochloremic, hypokalemic metabolic alkalosis with paradoxical aciduria. Vomiting causes loss of hydrogen (H⁺), chloride (Cl⁻), and potassium (K⁺). As hypokalemia worsens, the renal tubules exchange H⁺ for Na⁺ to preserve intravascular volume, leading to acidic urine despite systemic alkalosis.
• Abdominal Ultrasound: The diagnostic modality of choice. Confirms HPS when pyloric muscle thickness is >3 to 4 mm and pyloric channel length is >14 to 15 mm.

Emergency Nursing Priorities

1. Airway Protection & Gastric Decompression: Place infant on side or upright after feeds; insert a Salem sump nasogastric (NG) tube if vomiting is intractable.
2. NPO Status & Fluid Resuscitation: Maintain strict NPO status. Initiate IV fluid rehydration with isotonic crystalloid boluses (0.9% Normal Saline) to restore intravascular volume.
3. Electrolyte & Acid-Base Correction BEFORE Surgery: Pyloromyotomy (Fredet-Ramstedt procedure) is a semi-elective surgical repair. Surgery must be delayed until metabolic alkalosis and electrolyte deficits are fully corrected to prevent intraoperative and postoperative apnea.

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2. Intussusception

Intussusception occurs when a proximal segment of the intestine invaginates or "telescopes" into an adjacent distal intestinal segment, most commonly at the ileocecal junction (ileocolic intussusception).

+-----------------------------------------------------------------------+
| PROXIMAL BOWEL (Ileum)  =======>  [ DISTAL BOWEL (Colon) ]            |
| -> Telescoping leads to venous obstruction -> Edema -> Ischemia       |
| -> Mucosal sloughing -> "Currant Jelly Stool" -> Bowel Perforation   |
+-----------------------------------------------------------------------+

Epidemiology & Pathophysiology

• Peak Age: Most common cause of intestinal obstruction in children between 6 months and 3 years (peak 5 to 9 months).
• Etiology: >90% of pediatric cases are idiopathic, often preceded by a viral upper respiratory infection or gastroenteritis leading to hypertrophied Peyer’s patches that serve as a lead point. In children >3 years, pathologic lead points (e.g., Meckel diverticulum, intestinal polyp, duplication cyst, Henoch-Schönlein purpura) must be investigated.
• Ischemic Cascade: Telescoping compresses mesenteric blood vessels, causing venous stasis, severe bowel wall edema, arterial compromise, mucosal necrosis, and sloughing of mucosal tissue mixed with blood and mucus.

Clinical Manifestations

• Severe Episodic Colicky Pain: Sudden onset of severe, paroxysmal abdominal pain. The infant draws their knees up to the chest, screams hysterically, and appears inconsolable for 15 to 20 minutes.
• Quiescent / Lethargic Intervals: Between painful paroxysms, the child appears completely normal, calm, or progressively lethargic/somnolent due to endogenously released opioids or exhaustion.
• Currant Jelly Stool: Stools containing a mixture of dark red blood and mucus ("currant jelly stool") represent a late sign of advanced mucosal ischemia and sloughing.
• Abdominal Mass & Dance Sign: Palpable sausage-shaped mass in the right upper quadrant or epigastrium, with emptiness in the right lower quadrant (Dance sign).

Emergency Interventions & Management

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3. Pediatric Appendicitis

Appendicitis is the most common pediatric emergency surgical condition. Delayed diagnosis is frequent in infants and toddlers, resulting in perforation rates exceeding 80% in children under 5 years of age.

Clinical Presentation Nuances by Age

• Classic Presentation (Older Children & Adolescents): Vague periumbilical pain migrating to McBurney’s point (one-third the distance from the anterior superior iliac spine to the umbilicus), followed by anorexia, nausea, vomiting, low-grade fever, and focal RLQ peritoneal signs.
• Atypical Presentation (Infants & Toddlers <5 Years): Cannot localize pain. Present with nonspecific lethargy, irritability, fever, diffuse abdominal distension, refusal to walk, a limp, or pain when hopping ("heel-tap test" or "jump test").

Clinical Assessment Signs

• McBurney's Point Tenderness: Focal tenderness in the right lower quadrant.
• Rovsing's Sign: Palpation of the left lower quadrant causes referred pain in the right lower quadrant.
• Psoas Sign: Pain with passive hip extension (indicates retrocecal appendicitis).
• Obturator Sign: Pain with passive internal rotation of the flexed right hip (indicates pelvic appendicitis).

Diagnostic Workup & Emergency Nursing Care

• Ultrasound First: Abdominal ultrasound is the primary imaging modality to avoid ionizing radiation. Findings include a non-compressible, blind-ending tubular structure with an outer diameter >6 mm. Abdominal CT scan with IV contrast is reserved for equivocal ultrasound findings.
• Nursing Interventions:
  • Keep NPO; establish IV access and initiate isotonic hydration.
  • Administer IV broad-spectrum antibiotics (e.g., ceftriaxone plus metronidazole, or ampicillin/sulbactam) promptly, especially if perforation or peritonitis is suspected.
  • Analgesia: Administer IV opioids (e.g., morphine or fentanyl) as ordered; pain control does not obscure clinical examination or delay surgical decision-making.
  • CONTRAINDICATIONS: Never apply local heat to the abdomen or administer enemas/laxatives, as these increase intraluminal pressure and precipitate appendiceal rupture.

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4. Malrotation with Midgut Volvulus

Malrotation with Midgut Volvulus is a catastrophic, life-threatening surgical emergency occurring when the embryological gut fails to undergo normal 270-degree counterclockwise rotation and fixation, leaving a narrow mesenteric root.

Clinical Emergency & Pathophysiology

• Volvulus Mechanism: The narrow mesentery permits the entire midgut to twist around the superior mesenteric artery (SMA).
• Ischemic Timeline: SMA occlusion produces total midgut ischemia. Complete intestinal necrosis occurs within hours if surgical reduction is not performed immediately.

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CRITICAL CLINICAL PEARL: BILIOUS VOMITING IN AN INFANT
Any neonate or infant presenting with BILIOUS (bright green or yellow-green)
vomiting MUST be treated as Malrotation with Volvulus until proven otherwise!
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Clinical Presentation & Diagnostic Confirmation

• Bilious Vomiting: Sudden onset of green/yellow-green vomitus in a previously healthy neonate (75% present in the first month of life).
• Abdominal Findings: Initial exams may reveal a scaphoid, non-tender abdomen; as ischemia progresses, severe abdominal distension, peritonitis, hematochezia (late sign of bowel infarction), and hypovolemic/septic shock develop rapidly.
• Upper GI Series (Gold Standard): Radiographic finding of a "corkscrew" duodenal configuration or failure of the duodenojejunal junction (ligament of Treitz) to cross the midline to the left of the spine.

Emergency Nursing Actions

1. Immediate pediatric surgical consultation for an emergency Ladd procedure (untwisting volvulus, dividing Ladd's peritoneal bands, widening mesentery, appendectomy).
2. Establish two large-bore IVs or IO access and administer aggressive isotonic fluid boluses (20 mL/kg NS).
3. Place Salem sump NG tube on low continuous suction for gastric decompression.
4. Administer IV broad-spectrum antibiotics and prepare for immediate transfer to the operating room.

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5. Hirschsprung Disease (Congenital Aganglionic Megacolon)

Hirschsprung Disease is characterized by the congenital absence of parasympathetic ganglion cells (Auerbach and Meissner plexuses) in the distal bowel wall, extending proximally from the internal anal sphincter.

Pathophysiology & Clinical Features

• Functional Obstruction: Aganglionic bowel segment cannot relax, resulting in tonic contraction, functional intestinal obstruction, and massive dilation of the proximal, normally innervated colon (megacolon).
• Neonatal Presentation: Failure to pass meconium within 24 to 48 hours of life in a full-term infant, accompanied by abdominal distension, bilious vomiting, and feeding refusal.
• Digital Rectal Exam (DRE): Digital examination reveals a tight anal sphincter followed by an explosive release of gas and liquid stool ("blast sign" or "squirt sign").
• Diagnosis: Rectal suction biopsy demonstrating absence of ganglion cells is the definitive diagnostic gold standard.

Hirschsprung-Associated Enterocolitis (HAEC)

• Definition: A fulminant, life-threatening inflammatory complication of Hirschsprung disease caused by bacterial overgrowth, stasis, and mucosal ischemia.
• Clinical Signs: High fever, severe abdominal distension, foul-smelling explosive diarrhea, lethargy, and rapid progression to septic shock and bowel perforation.
• Emergency Management: Immediate aggressive IV fluid resuscitation, NPO status, placement of an NG tube, IV broad-spectrum antibiotics covering enteric gram-negative and anaerobic pathogens, and emergency serial rectal irrigations with warm normal saline (using a large-bore rectal tube) to decompress the colon.

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Chronic Gastrointestinal Conditions in the ED (IBD and GERD)

System-Focused GI blueprint content includes chronic conditions such as inflammatory bowel disease (IBD) and gastroesophageal reflux disease (GERD), not only acute surgical emergencies.

Inflammatory Bowel Disease (Crohn Disease / Ulcerative Colitis)

Adolescents with known IBD may present with flare (crampy abdominal pain, bloody diarrhea, fever, weight loss) or complications:

• Abscess / fistula / perforation → peritonitis signs, sepsis pathway
• Toxic megacolon (more typical of ulcerative colitis) → marked distension, toxicity, risk of perforation; NPO, IV fluids, antibiotics, surgical consult, avoid antimotility agents
• Severe anemia / dehydration from ongoing GI losses
• Medication-related issues (steroid-dependent patients may need stress-dose steroids during critical illness—confirm home regimen)

ED priorities: ABCs, isotonic fluid resuscitation for hypovolemia, CBC/CRP/ESR/electrolytes, stool studies when infection must be excluded, early GI/surgery involvement for peritonitis or obstruction, and careful immunosuppression history (anti-TNF agents raise infection risk).

GERD and Related ED Presentations

GERD is common in infants and children; emergency relevance includes:

• Poor weight gain / feeding aversion overlapping failure-to-thrive workups
• Aspiration risk with frequent regurgitation in neurologically impaired children
• Distinguishing simple spit-up from bilious emesis (surgical emergency), hematemesis, or apnea/ALTE-type events in infants

Teach caregivers warning signs that require return: bilious vomiting, lethargy, respiratory distress with feeds, or bloody stools.