FRCA Notes

Bronchopleural Fistula

The curriculum asks for knowledge of 'the common problems associated with the postoperative care of patients who have had thoracic surgery', of which this is one.

As with massive haemoptysis, the topic could feasibly form the basis of a question on one-lung ventilation.

Resources

  • An abnormal, persisting (>24hrs) communication between the bronchial tree and pleural space
  • It is associated with a high (up to 67%) mortality
  • Right (as opposed to left) pneumonectomy; incidence as high as 20%
  • Residual tumour in bronchial stump
  • Large diameter stump
  • High suction on chest drain

  • Ventilation
    • Prolonged post-operative ventilation
    • High inspiratory pressures
    • High tidal volume

  • By far the most common cause is PPV following surgical intervention e.g. pneumonectomy, lobectomy, lung biopsy
  • Presents 3 - 10 days post-surgery
Classification Examples
Infection Lung abscess
Empyema
TB
Aspergillus
Trauma Ruptured bullae
Thoracic trauma
Gastrointestinal Barrett's oesophagus + rupture
Boerhaave syndrome
Neoplastic Bronchial tumour
Oesophageal tumour
Iatrogenic Post-thoracotomy
Bronchoscopic airway trauma
Post-chemo/radiotherapy
Bougie during intubation
CVC replacement


  • In bronchopleural fistula following pneumonectomy, there is dehiscence of the bronchial stump and thus an abnormal bronchial-pleural communication

  • More common following right pneumonectomy as:
    1. The right main bronchus has only a single arterial supply (right bronchial artery) vs. the two left bronchial arteries
    2. The right bronchial stump is exposed following surgery and requires a surgically-crafted flap to protect it
    3. The left bronchial stump typically retracts into the aortopulmonary window and is protected by native mediastinal tissue

  • Severity of leak can be established by degree of pneumothorax bubbling:
    • Inspiration only
    • Inspiration & expiration
    • Inspiration and expiration with detectable volume difference of >100ml per breath

Early (<2 weeks)

  • Cough
  • Dyspnoea
  • Hypoxia
  • Continued air leak from chest drain
  • New or changing air-fluid level on chest radiograph
  • Pneumothorax or pneumomediastinum

Late (>2 weeks)

  • Features may be non-specific
  • Empyema ± sepsis

  • Antibiotics
  • High FiO2 may denitrogenate the pneumothorax and allow healing
  • Large bore chest drain with minimal/low/no suction

Ventilatory strategy

  • Issues here include:
    • V/Q mismatching causing hypoxia and hypercapnoea
    • Need to use strategies to limit flow in order to aid fistula healing, but these impair ventilation
    • Need to use selective ventilation of the two lungs e.g. with a DLT or HFOV, which each carry their own complications

  • Keep patient spontaneously breathing with chest drain on low suction
    • Avoid PPV
    • Excessive suction will perpetuate the fistula

  • If mandatory ventilation is required:
    • Use DLT
    • Use two ventilators, one for each lung
    • For bad lung, try to aid healing of the fistula with:
      • Low RR
      • Low tidal volume
      • Short Ti
      • Low PEEP and Pinsp
      • No suction on chest drain
    • Early weaning and extubation

  • High-frequency oscillatory ventilation
    • Reduces tidal volume and possibly peak pressures too
    • Theoretically reduces flow across the fistula, allowing it to heal
    • Is an unnatural form of ventilation which is poorly tolerated and requires high sedation loads ± paralysis

  • ECMO

Surgical

  • Used to treat large bronchopleural fistulae which are either not amenable to, or have failed, conservative management

  • Bronchoscopy & application of sealants or patches/stents, which may be suitable for small bronchoscopically-accessible leaks
  • VATS
  • Thoracotomy and flap closure, additional lobectomy or decortication