BPF

Asian Intensive Care: coming of age
International intensive care conference, Hong Kong, December 14th-15th
Register now!
Click here for details

Continued air leak for >24 h after development of a pneumothorax

- persistent pneumothorax
- inadequate ventilation
- VQ mismatching
- infection of pleural space
- inability to maintain PEEP
- inappropriate cycling of ventilator

- direct trauma
- iatrogenic: puncture, laceration, barotrauma
- spontaneous alveolar rupture
- necrotizing infection
- acute lung injury

Main factors which perpetuate BPF are:

• high airway pressures that increase leak during inspiration
• increased mean intrathoracic pressures throughout the respiratory cycle (PEEP, inspiratory pause, high I:E) that increase leak throughout the breath
• high negative suction

All these factors tend to be present in patients with ARDS because they are necessary to support gas exchange and lung inflation

- large chest drain to allow sufficient gas flow. Air leaks range from 1-16 l/min
- application of positive intrapleural pressure equivalent to PEEP via chest tube ± synchronized closure of chest tube during inspiration has been tried in an attempt to decrease leak. Risk of increased or tension pneumothorax and very close observation is essential
- ensure drainage system is capable of dealing with flow rates
- ventilation: aim is to reduce flow through fistula to promote healing and to decrease wasted ventilation while still maintaining adequate ventilation and oxygenation. Use lowest possible tidal volumes, ventilatory rates, PEEP and inspiratory time. Encourage spontaneous breathing. IMV may have an advantage over assist control
- high frequency jet ventilation (HFJV) may be useful in severe BPF, particularly when there is a tracheal or bronchial fistula in the presence of normal lung parenchyma
- independent lung ventilation may be useful
- bronchoscopy may be useful to identify sites of proximal leak and can be used to localize distal leaks with the use of a balloon catheter passed down the suction channel and into more distal airways. Reduction of air leak on inflation of balloon indicates that catheter is in correct area. An occluding material can then be injected. For distal fistulae a PA catheter has been used. Experience with this technique is extremely limited. It cannot be used for proximal leaks
- definitive management frequently involves surgery including thoracoplasty, mobilization of pectoralis or intercostal muscles, bronchial stump stapling and decortication

- mortality higher when:

• BPF develops late in the illness of a mechanically ventilated patient
• not related to chest trauma
• volume of leak greater (leaks of 500 ml or more associated with 100% mortality in one study)

© Charles Gomersall December 1999

©Charles Gomersall, October, 2009 unless otherwise stated. The author, editor and The Chinese University of Hong Kong take no responsibility for any adverse event resulting from the use of this webpage.
Copyright policy    Contributors