Lung abscess (Lungenabszess)

General information:

• Result of a necrotizing pneumonia (e.g. after aspiration of gastric juice, GER).
  
• Streptococci, Staphylococcus aureus, Klebsiella pneumoniae, Pseudomonas aeruginose, or other gram – negative enteric organisms have been found to be responsible.
  
• Frequent in children with neurological impairment, seizure disorders and immune suppression.
  
• Location: posterior segment of the right upper lobe and the superior segments of the right and left lower lobe.
  
• 10% of the affected children have more than one abscess.
  
• Notice the probability of an abscess formation in etiological connection with an unknown pre-existing localized pulmonary malformation (CCAM, bronchogenic cyst, lung cyst, infected sequestration).

Symptoms:

• Cough, fever, tachypnea, decreased (no) breathing sounds and dullness to percussion on the involved side.
  
• Respiratory distress.
  
• Pulmonary infiltrate, cavity with fluid level.
  
• Usually quick development of pleural effusion.
  
• Perforation into the pleural cavity leads to empyema usually combined with pneumothorax.

Diagnostic workout:

• Thoracic X-ray, CT or MRI scan.
  
• Bronchial lavage guided by flexible fiberoptic bronchoscopy or thoracocentesis is useful in obtaining culture material used to determine specific antibiotic treatment.

Indication for operation:

• Bronchopleural fistula.
  
• Operation frequently needed in younger and more debilitated children.
  
• Large abscesses (approx. more than 5 cm in diameter) with fluid levels, especially located near the lung surface, unresponsive after aggressive conservative treatment.
  
• No complete expansion of the lung over a period of about two weeks.

Treatment/Operation:

• Intravenous antibiotic management continued orally.
  
• Closed drainage (multiple chest tubes sometimes necessary).
  
• Open drainage (including decortication) of the pleural effusion usually with two large chest tubes.
  
• Resection, usually of the complete involved lobe (covering the bronchial closure additionally with a dorsally based intercostal muscle flap). Care must be taken with the induction of anaesthesia or positioning the patient to prevent a spill of the abscess contents into the contralateral lung (bronchoscopically guided suction before!).

Postoperative management:

• Chest tubes may be removed if the lung is fully expanded and drainage volumes decrease below 20 to 50cc during a 24 hours period.
  
• Antibiotic management continued orally after release from the hospital.

Prognosis:

• Good.
  
• Resolution of a sufficiently drained abscess needs several weeks.

Pneumatocele

General information:

• Thin walled, air filled cyst usually after a necrotizing Staphylococcus aureus pneumonia (other germs involved: Streptococcus, Hemophilus influenzae, Klebsiella, E. coli and Pseudomonas).
  
• Endotoxin released from the staphylococcal organisms contributes to the extremely destructive inflammatory process.
  
• Mechanically ventilated patients are at increased risk of developing pneumatocele.
  
• Adjacent structures may be compressed or a mediastinal shift may occur, when tension pneumatocele develops.
  
• 25% of the pneumatoceles rupture, causing a usually insignificant pneumothorax.

Symptoms:

• Respiratory insufficiency.

Diagnostic workout:

• Thoracic X-ray or CT scan.
  
• Thoracic ultrasound.

Indication for operation:

• Rapidly enlarging pneumatocele producing mediastinal shift (tension pneumatocele).

Treatment/Operation:

• Most pneumoatoceles require no treatment, just observation.
  
• Percutaneous needle aspiration or chest tube for drainage in large cysts.
  
• Thoracotomy, suture or resection is rarely necessary.

Postoperative management:

• Chest tubes may be removed if the lung is fully expanded and drainage volumes decrease below 20 to 50cc during a 24 hour period.
  

Prognosis:

• Good. About 50% resolve within 6 weeks and the remainder within 12 months.