Complications of Pediatric Pneumonia
Pulmonary Complications
Pleural Effusion
- Parapneumonic effusion — sterile exudate adjacent to pneumonia; most common
- Identified by CXR (blunting of CP angle) and USS
- Small effusions resolve with antibiotic treatment
- Large effusions require thoracocentesis for diagnosis and drainage
Empyema (Pyothorax)
- Definition: Frank pus in the pleural cavity
- Most common organism in children <2 years: S. aureus (Staphylococcal)
- Other organisms: S. pneumoniae, H. influenzae, Gram-negatives
- Signs: Persistent fever despite antibiotics, respiratory distress, dullness on percussion, absent breath sounds
- CXR: Dense pleural opacity, mediastinal shift
- Treatment: Intercostal drainage (ICD) under water seal or low-pressure aspiration + IV antibiotics
Pyopneumothorax
- Air + pus in pleural space
- Pathognomonic of staphylococcal pneumonia (along with pneumatoceles)
- CXR: air-fluid level in pleural space
- Treatment: ICD under water seal
Pneumatoceles
- Thin-walled, air-filled cysts within lung parenchyma
- Pathognomonic of Staphylococcal pneumonia
- Mechanism: Suppurative lesions → microabscesses → erode bronchial wall → air-filled cysts form progressively
- Usually resolve spontaneously — no specific treatment needed
- Risk: if enlarging, may cause respiratory compromise or rupture
Lung Abscess
- Primary: Aspiration, foreign body, post-obstructive
- Secondary (metastatic): Hematogenous spread from staphylococcal septicemia
- May also occur with Gram-negative organisms (Klebsiella)
- Treatment: Prolonged antibiotics; surgical drainage for metastatic abscesses
- Significant pleural thickening: decortication (thoracotomy or VATS)
Cardiovascular Complications
Purulent Pericarditis
- Staphylococcal lung abscess may erode directly into the pericardium
- Presents with: chest pain, friction rub, muffled heart sounds, pulsus paradoxus
- Treatment: Pericardiocentesis + IV antibiotics (anti-staphylococcal cover)
Septicemia (Bacteremia)
- Particularly with H. influenzae and S. aureus
- H. influenzae pneumonia: nearly always associated with bacteremia
- Presents with toxaemia, high fever, poor perfusion
- Blood culture essential
CNS Complications
- Meningitis: H. influenzae pneumonia — spread via bacteremia
- Meningismus: Apical pneumococcal pneumonia — neck stiffness without meningitis
- Brain abscess (metastatic): Staphylococcal dissemination
Disseminated (Metastatic) Disease — Staphylococcal
Staphylococcal bacteremia → abscesses in:
- Joints (septic arthritis)
- Bone (osteomyelitis)
- Muscles
- Pericardium (purulent pericarditis)
- Liver
- Mastoid
- Brain
Respiratory Failure
- End-stage of severe untreated pneumonia
- Indication for mechanical ventilation: SpO₂ <88% despite high-flow oxygen, rising PaCO₂, worsening sensorium
- CPAP for moderate respiratory distress
- IPPV / mechanical ventilation for respiratory failure
- Extracorporeal membrane oxygenation (ECMO) in extreme cases
Systemic Complications
| Complication | Mechanism |
|---|---|
| SIADH | ADH release due to hypoxia / infection → hyponatremia |
| Febrile convulsions | High fever in young children |
| Septic shock | Gram-negative / Staphylococcal bacteremia |
| Malnutrition | Prolonged illness → poor intake |
Complications by Organism — Quick Reference
| Organism | Key Complications |
|---|---|
| S. aureus | Pneumatoceles, empyema, pyopneumothorax, pericarditis, metastatic abscesses |
| H. influenzae | Bacteremia, meningitis, pericarditis, polyarthritis |
| S. pneumoniae | Empyema, meningitis, bacteremia (5–10%) |
| Streptococcus (Group A) | Serosanguineous empyema (thin, purulent) |
| Gram-negatives | Pneumatoceles (E. coli, Klebsiella) |