Question 23

Created on Wed, 06/29/2016 - 20:18
Last updated on Fri, 04/28/2017 - 16:34
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Outline the strategies for management of a persisting broncho-pleural fistula (BPF) in a mechanically ventilated patient. Include in your answer, where relevant, the advantages and disadvantages of the strategies listed.

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College Answer

Principles of Management:

1. Drainage                                                                                                                                                 

  • Adequate drainage of the fistula with an intercostal catheter of adequate size to manage a large air leak.
  • May require multiple catheters, and ability to manage large flow rates.
  • Minimise suction.                                                                                                                                                                 

2.Ventilatory management                                                                                                    

  • Aim is to reduce mean airway pressure to reduce flow through fistula tract.
  • Low tidal volume and PEEP.
  • Low mandatory breath rate.
  • Permissive hypercapnoea.
  • Short inspiratory time.
  • Attempt to wean to spontaneous breathing mode from mandatory ventilation as soon as practicable and preferably from ventilatory support altogether.

3. Independent Lung Ventilation                                                                                           

  • Advantages: - May minimise leak in injured lung whilst preserving gas exchange with conventional parameters in normal lung.
  • Disadvantages: -requires some form of double lumen tube – difficult to place and secure.
  • May not be tolerated in hypoxic patients.
  • Requirement for two ventilators –either synchronous or asynchronous – technically demanding and complex.                                                            

4.High Frequency Ventilation                                                                                                                

  • Advantages are that it may reduce peak air pressures and theoretically reduce air leak.
  • Disadvantages - not widely available. Recent evidence suggesting an increase in mortality for this ventilatory technique in ARDS patients.      

5.Surgery                                                                                                                                  

  • Advantages – Definitive management strategy. May be only option to seal leak.  Disadvantages – Patient may not be fit enough to tolerate.                             

6. Endobronchial Occlusion                                                                                                                    

  • Advantages – Widely available, can be definitive treatment.
  • Disadvantages – may be technically challenging, not feasible with multiple leaks.

7. Application of PEEP to intercostal catheter                                                   

  • Advantages – may decrease leak volume and maintain intra-thoracic PEEP.
  • Disadvantages – compromise drainage, risk of tension, not feasible with multiple tubes.

8. ECMO                                                                                                                                                      

  • Advantages – may be only option to treat hypoxia.
  • Disadvantages – not widely available, complex, little experience.

Discussion

Management Strategies for Bronchopleural Fistula
Strategy Advantages Disadvantages
Drainage
- large-bore drain
- or, multiple drains
- minimise suction
  • easy and readily available
  • Usually well tolerated
  • Does not interfere with weaning of ventilation
  • Risk of damaging more lung and creating larger leaks
  • Potentially, perpetuates the fistula by negative pressure suction
  • Invasive
Ventilator strategy:
- low VT
- low PEEP
- low resp rate
- short insp. time
- tolerate high PCO2
- wean rapidly
- extubate early
 
  • easy and readily available
  • Usually well tolerated
  • Early extubation is the ideal step to aim for, as spontaneous negative pressure breathing is better for BPF healing than positive pressure ventilation.
  • The BPF itself may frustrate weaning off ventilation
  • Mandatory mode may prolong ventilation time
  • Permissive hypercapnea may lead to respiratory acidosis, which is not ideal for the patient with traumatic brain injury
Independent lung ventilation
- dual-lumen tube
- or, bronch blocker
 
  • Isolation of one lung permits the selective low-volume low-pressure ventilation of the affected lung, and more rapid higher volume ventilation of the unaffected lung.
  •  PCO2 levels may be easier to control in this manner
  • Technically difficult: DLT insertion is one thing; running two ventilators is another.
  • There may be leak of gas and pressure from one lung to another if the seal is imperfect
  • Sedation requirements will  be higher, to tolerate the larger tube and the very unnatural respiratory pattern
  • Local pressure effects of the DLT are also more problematic
     
Surgical repair
  • The affected lung can be surgically repaired. USually, this means segmental lobectomy (for alveolar leaks) or patching and oversowing of the bronchial leak
  • Apparently, success rates are between 80 and 95%
  • It may be impossible to find the leak intraoperatively
  • It may be unfeasible to remove so much lung
  • It may be impossible if there are multiple leaks
  • The patient must tolerate one-lung ventilation
  • This approach requires thoracotomy
Bronchial stenting
  • The affected bronchus can be stented over bronchoscopically, thereby blocking the leak.
  • This is a minimally invasive alternative to surgical patch repair
  • You need to be sure of where the leak is
  • The leak must be in an accessible bronchus.
  • This may not work if there are multiple leaks
  • The procedure requires technical expertise
  • The patient must be fit to tolerate the bronchoscopy
Bronchial occlusion
  • Similarly to surgery, the affected pronchus is blocked with either a one-way valve or a plug. In fact, the Lois article lists options such as blood clot, cyanoacrylate glue, fibrin, lead shot,  gel foam, calf bone, and various others.
  • You need to be sure of where the leak is
  • The leak must be in an accessible bronchus
  • A major part of the lung may be sacrificed
  • The atelectatic lung may develop infection
Application of PEEP to the ICC
  • The equal intra and extrathoracic PEEP decreases the leak volume
  • Maintained intra-thoracic PEEP permits higher PEEP levels to be used
  • Drainage is compromised
  • There is a major risk of rapid tension pneumothorax
HFOV
  • May reduce peak pressures
  • Certainly reduces tidal volume (to ~50ml)
  • Thus, theoretically reduces flow across the BPD, allowing it to heal
  • This is avery unnatural form of ventilation, and may be poorly tolerated
  • Large amounts of sedation or paralysis will be required
ECMO
  • This may be the only option for severely hypoxic patients
  • With ECMO, one can limit or totally abolish gas flow through the BPF
  • All the risks of ECMO apply, as it is a maximally invasive therapy
  • It is not widely available.
  • There is little experience with this in BPF.

References

Lois, Manuel, and Marc Noppen. "Bronchopleural fistulas: an overview of the problem with special focus on endoscopic management." CHEST Journal 128.6 (2005): 3955-3965.

Baumann, Michael H., and Steven A. Sahn. "Medical management and therapy of bronchopleural fistulas in the mechanically ventilated patient." CHEST Journal 97.3 (1990): 721-728.

Pierson, David J., et al. "Management of bronchopleural fistula in patients on mechanical ventilation." (2012) - from UpToDate.