Chronic lung infections

BRONCHIECTASIS

J47

DESCRIPTION

Irreversible dilatation of the subsegmental airways, inflammatory destruction of bronchial and peribronchial tissue, and accumulation of exudative material in dependent bronchi that occurs as a result of recurrent bacterial infections and aspiration pneumonia. There is bronchial luminal obstruction; ciliary dyskinesia; thick, tenacious secretions and lung tissue damage.

Complications include pulmonary hypertension, cor pulmonale and respiratory failure. Predisposing conditions include HIV, TB, cystic fibrosis, primary ciliary dyskinesia and primary immunodeficiency syndromes.

DIAGNOSTIC CRITERIA

  • Chronic cough, usually with mucopurulent sputum and occasional haemoptysis.
  • Clubbing and halitosis.
  • Recurrent and persistent lower respiratory tract infections.
  • A bout of coughing on physical activity or change in posture, particularly while reclining.
  • Fever, malaise, anorexia, poor weight gain.
  • Respiratory failure, cyanosis
  • Pulmonary hypertension and cor pulmonale.
  • Chest X-ray showing cystic dilatation and tram tracking.
  • If diagnosis is uncertain or where localised disease on chest X-ray is suspected, perform high resolution computed tomography. Features include cystic dilatation, signet ring sign and tram tracking.

GENERAL AND SUPPORTIVE MEASURES

  • Identify and treat the underlying disorder or bacterial source.
  • Clear secretions effectively with postural drainage and physiotherapy.
  • Eliminate all foci of infection.
  • Nutritional support.

Method of sputum induction

Precaution: If undertaking procedure in acutely sick child with respiratory compromise, be prepared to manage acute bronchospasm as this may be an associated adverse effect.

  • Nebulise with sodium chloride 0.9% or sodium chloride 3% (hypertonic saline) to aid sputum expectoration. Mix 3 mL of 5% sodium chloride with 2 mL water to make 3% solution.

In the acutely sick child:
Nebulise with a bronchodilator:

  • Salbutamol, solution, 0.15–0.3 mg/kg/dose in 2–4mL of sodium chloride 3% delivered at a flow of 5 L/minute with oxygen for 20 minutes.
    • Perform physiotherapy.
    • Encourage patient to cough up sputum or if infant or small child obtain nasopharyngeal aspirate post physiotherapy.
    • Send sample for culture and cytology as indicated.

SURGICAL TREATMENT

Consider in localised severe disease or progressive disease despite adequate medical treatment.

MEDICINE TREATMENT

Acute lung infections: worsening cough accompanied by increased dyspnoea or tachypnoea and/or signs of sepsis.

Empiric antibiotic therapy for acute lung infections:

  • Ampicillin, IV, 25 mg/kg/dose, 6 hourly.

PLUS

  • Gentamicin, IV, 6 mg/kg once daily.

Change antibiotics according to culture and sensitivity results.

If poor response and no culture to guide antibiotic choice, consider infection due to S. aureus , TB or fungal infection.

If there is evidence of good clinical response, change to:

  • Amoxicillin/clavulanic acid, oral, 45 mg/kg/dose of amoxicillin component 12 hourly.
    • Total antibiotic duration of 14 days.

Note: These antibiotic regimens do not apply to children with cystic fibrosis , seek specialist advice.

In the acute phase if wheeze is present:

  • Salbutamol solution, 5 mg/mL, nebulise 4 hourly.
    • 5 mg salbutamol in 2–4 mL sodium chloride 0.9%.
  • Annual influenza vaccination.
  • Pneumococcal vaccine (conjugated), 2 additional doses 8 weeks apart.

REFERRAL

  • All patients for confirmation of the diagnosis, assessment of severity and evaluation of underlying condition.
  • Poor response to therapy, increased frequency of exacerbations, poor lung function.
  • For early surgical intervention of localised disease.

LUNG ABSCESS

J85

DESCRIPTION

A suppurative process that results from destruction of the pulmonary parenchyma and formation of a cavity. The cavity may be single, e.g. after aspiration or multiple, e.g. staphylococcal disease and cystic fibrosis.
Lung abscess may follow pneumonia caused by:

  • S. aureus ,
  • K. pneumoniae ,
  • anaerobic organisms,
  • S pneumoniae ,
  • H. influenza ,
  • M. tuberculosis .

Metastatic lung abscesses due to septicaemia or septic emboli may also occur.

Complications include:

  • bronchiectasis,
  • rupture into the bronchial tree or pleural cavity or vessels,
  • empyema,
  • pulmonary osteo-arthropathy,
  • brain abscess,
  • bronchopleural fistula.

DIAGNOSTIC CRITERIA

  • Intermittent or recurrent fever, malaise, weight loss, anorexia and clubbing.
  • Productive, purulent cough with halitosis and haemoptysis.
  • Amphoric breathing over the cavity may be present.
  • Chest X-ray will confirm cavity/cavities with or without an air-fluid level.

GENERAL AND SUPPORTIVE MEASURES

  • Identify underlying cause.
  • Physiotherapy and postural drainage.
  • Correct anaemia.
  • Nutritional support.

MEDICINE TREATMENT

Empiric antibiotic therapy for at least 14 days.

  • Ampicillin, IV, 25 mg/kg/dose, 6 hourly.

PLUS

  • Gentamicin, IV, 6 mg/kg/day as a single daily dose.

PLUS

  • Metronidazole, IV, 7.5 mg/kg/dose, 8 hourly.

Change antibiotics according to culture and sensitivity results.
Poor response and no culture to guide antibiotic choice:
ADD

  • Cloxacillin, IV, 50 mg/kg/dose, every 6 hours.

If there is evidence of good clinical response, change to:

  • Amoxicillin/clavulanic acid, oral, 45 mg/kg/dose of amoxicillin component 12 hourly.

SURGICAL TREATMENT

Consider surgical drainage of abscess and/or resection if medical treatment fails.

REFERRAL

  • Complicated lung abscess not responding to therapy.
  • Lung abscess where the underlying cause has not been established.