A 3-year-old boy is brought to the emergency department by his mother with a 6-hour history of sudden-onset coughing and difficulty breathing. The mother reports that he was playing with peanuts in the living room when he suddenly started coughing violently. On examination, the child is in mild respiratory distress with stridor. Chest auscultation reveals decreased air entry on the right side with occasional wheezing. Chest X-ray (inspiratory) appears normal, but expiratory film shows hyperinflation of the right lung with mediastinal shift to the left. What is the most appropriate next step in management?

## Clinical Diagnosis **Key Point:** The clinical presentation of sudden-onset coughing, unilateral decreased air entry, and unilateral hyperinflation on expiratory X-ray is pathognomonic for **aspirated foreign body (FB) in the main bronchus**. ## Pathophysiology of Aspirated FB 1. **Mechanism of air trapping:** The FB acts as a one-way valve—air enters during inspiration but cannot exit during expiration due to dynamic airway compression, causing distal hyperinflation. 2. **Why expiratory film is diagnostic:** Inspiratory films may appear normal because the FB does not completely obstruct airflow. The expiratory film reveals the characteristic **unilateral hyperinflation with mediastinal shift** away from the affected side. 3. **Right-sided predominance:** ~70% of aspirated FBs lodge in the right main bronchus due to its more vertical orientation. ## Management Algorithm ```mermaid flowchart TD A[Suspected aspirated FB in child]:::outcome --> B{Stable airway?}:::decision B -->|Yes, partial obstruction| C[Rigid bronchoscopy under GA]:::action B -->|No, complete obstruction| D[Emergency airway management]:::urgent C --> E[FB removal + post-op monitoring]:::action D --> E E --> F[Repeat imaging + follow-up]:::action ``` **High-Yield:** Rigid bronchoscopy is the gold standard for diagnosis AND treatment of aspirated FB. It allows: - Direct visualization of the FB - Controlled removal with appropriate instruments - Assessment of airway damage - Prevention of further distal migration **Clinical Pearl:** Flexible bronchoscopy is contraindicated in acute FB aspiration because it cannot provide adequate airway control or secure removal of the FB, and may push the FB deeper into the airway. ## Why Immediate Bronchoscopy? **Key Point:** Delayed removal increases risk of: - Airway edema and inflammation - Secondary bacterial infection (bronchitis, pneumonia) - Granulation tissue formation - Permanent airway damage [cite:Scott-Brown's Otolaryngology 7e Ch 29]