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Difficulty: HardPediatric Cardiovascular Disorders

Match the following clinical vignettes describing postoperative complications in pediatric cardiac surgery patients with their corresponding underlying pathophysiologic mechanism.

  • A 4-year-old child presents with low-grade fever, irritability, and chest pain that worsens when supine, occurring three weeks following surgical closure of an atrial septal defect. A friction rub is auscultated on exam.Immune-mediated pleuropericardial inflammation
  • A 6-month-old infant exhibits persistent respiratory effort and right-sided atelectasis one week after an arterial switch operation. Fluoroscopic evaluation demonstrates paradoxical upward movement of the right hemidiaphragm during spontaneous inspiration.Iatrogenic phrenic nerve neurapraxia
  • A 2-year-old child requires prolonged chest tube drainage five days after a bidirectional Glenn shunt. The drained pleural fluid is milky, densely populated with lymphocytes, and has a significantly elevated triglyceride concentration.Traumatic disruption of the thoracic duct
  • A 4-month-old infant becomes abruptly hypotensive 12 hours post-ventricular septal defect repair. Electrocardiography reveals a narrow-complex regular rhythm at 210/min with independent, slower atrial activity (atrioventricular dissociation).Enhanced automaticity of the atrioventricular junction

Answer

The correct matches align the delayed febrile presentation with immune-mediated pleuropericardial inflammation (post-pericardiotomy syndrome); the paradoxical diaphragmatic movement with iatrogenic phrenic nerve neurapraxia; the milky, triglyceride-rich pleural effusion with traumatic disruption of the thoracic duct (chylothorax); and the narrow-complex tachycardia with AV dissociation with enhanced automaticity of the atrioventricular junction (junctional ectopic tachycardia).
Each postoperative complication has a distinct pathophysiologic mechanism directly tied to its clinical presentation. Post-pericardiotomy syndrome is an immune response causing delayed pericarditis. Phrenic nerve injury causes failure of the diaphragm to contract, leading to paradoxical upward motion pulled by negative intrathoracic pressure. Thoracic duct injury leaks lipid-rich chyle into the pleural space. Direct trauma to the conduction system during VSD repair irritates the AV node, causing an automatic junctional tachycardia that functionally dissociates from the sinoatrial node.

Step-by-Step Solution

1
Evaluate the 4-year-old presenting weeks after surgery with fever and positional chest pain.
Identify post-pericardiotomy syndrome, which is driven by immune-mediated pleuropericardial inflammation.
Late-onset sterile inflammation of the pericardium is a known auto-immune response following surgical disruption of the pericardial sac.
2
Analyze the fluoroscopy findings in the 6-month-old infant with respiratory distress.
Identify diaphragmatic paralysis caused by iatrogenic phrenic nerve neurapraxia.
Paradoxical upward movement of the diaphragm during inspiration is the hallmark of phrenic nerve injury, a recognized complication of dissecting near the great vessels.
3
Assess the characteristics of the chest tube output in the 2-year-old child.
Diagnose chylothorax caused by traumatic disruption of the thoracic duct.
Milky pleural fluid with high triglycerides and lymphocyte predominance uniquely characterizes chyle, which leaks when the thoracic duct is injured.
4
Interpret the ECG findings of the hypotensive 4-month-old following VSD repair.
Identify junctional ectopic tachycardia (JET) caused by enhanced automaticity of the atrioventricular junction.
Tachycardia with a narrow QRS complex and AV dissociation in the immediate postoperative period of a VSD repair is pathognomonic for JET due to local trauma/edema to the AV node.

Key Concept

Postoperative Complications in Pediatric Cardiac Surgery
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Topics

Pediatric Cardiovascular Disorders

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