A 5-year-old girl is brought to the ENT clinic 3 days after her parents noticed she was coughing intermittently and had a low-grade fever (38.2°C). She had been playing with small toy beads the previous week. On examination, she is afebrile now, with mild bilateral wheezing on auscultation. Anteroposterior and lateral neck X-rays are normal. Chest X-ray shows patchy consolidation in the right lower lobe. Flexible bronchoscopy reveals a small plastic bead lodged in the right lower lobe bronchus with surrounding mucosal edema and purulent secretions. What is the most likely complication that has already occurred?

Explanation

## Clinical Diagnosis **Key Point:** This child has a **post-obstructive pneumonia** — a common complication of delayed FB removal. The triad of fever, consolidation on imaging, and purulent secretions around the FB is pathognomonic. ### Pathophysiology of Post-Obstructive Pneumonia ```mermaid flowchart TD A[FB lodges in bronchus]:::outcome --> B[Distal airway obstruction]:::outcome B --> C[Impaired mucociliary clearance]:::outcome C --> D[Stasis of secretions]:::outcome D --> E[Bacterial overgrowth]:::outcome E --> F[Inflammation + Consolidation]:::action F --> G[Fever + Cough + Purulent sputum]:::outcome ``` ### Timeline of Complications | Time Frame | Complication | Clinical Features | |------------|--------------|-------------------| | **Acute (0–24 hrs)** | Airway obstruction | Stridor, cyanosis, respiratory distress | | **Subacute (1–7 days)** | Post-obstructive pneumonia | Fever, cough, consolidation, purulent secretions | | **Chronic (>2 weeks)** | Bronchiectasis, granulation, stenosis | Persistent cough, recurrent infections | **High-Yield:** Post-obstructive pneumonia occurs because: 1. The FB blocks normal airflow and mucociliary clearance 2. Secretions pool distal to the obstruction 3. Bacteria (typically *Streptococcus pneumoniae*, *Haemophilus influenzae*) proliferate 4. Inflammation and consolidation develop **Clinical Pearl:** The presence of **purulent secretions** around the FB on bronchoscopy is the gold standard for diagnosing post-obstructive pneumonia. The patchy consolidation on chest X-ray (typically in a lobar or segmental distribution) confirms the diagnosis. [cite:Dhingra 8e Ch 12] ### Management of Post-Obstructive Pneumonia 1. **Immediate:** Rigid bronchoscopy for FB removal (do NOT delay) 2. **Antibiotics:** Broad-spectrum coverage (amoxicillin-clavulanate or second-generation cephalosporin) pending culture 3. **Supportive care:** Oxygen, hydration, antipyretics 4. **Follow-up:** Repeat chest X-ray in 2–4 weeks to ensure resolution **Warning:** Do NOT assume the consolidation will resolve after FB removal — antibiotics are essential. Persistent consolidation after 4 weeks suggests bronchiectasis or abscess formation.