19. Bronchopleural Fistula Flashcards
Can you tell me what a bronchopleural fistula (BPF) is?
This is a communication between the pleural cavity
and the trachea or a bronchus.
Clinically, this is seen as a persistent air leak for greater
than 24 hours after the development of a pneumothorax.
Why does it occur?
- After lung resection.
Most commonly associated with dehiscence of a
bronchial stump (usually 3–10 days post-op). - Tumour invasion of a bronchus.
- Blunt or penetrating trauma
with disruption of a major bronchus. - Spontaneous pneumothorax
may result in a BPF, seen as persistent bubbling
through an underwater seal chest drain. - Necrotising infection
such as pneumonia, lung abscess, empyema or TB can cause BPF. - ARDS or acute lung injury may be complicated by BPF
How does it usually present?
The presentation depends on the size
of the air leak and the underlying pathology.
- Persistent bubbling from the chest drain.
- Cough which may be productive of foul sputum.
- Dyspnoea the degree of which will depend on the lung compromise and
whether the pleural cavity has been drained with a chest drain. - Systemic features of sepsis if the cause is infective.
- An acute BPF with a large leak causes severe dyspnoea and may cause a
tension pneumothorax if it is not drained (especially if CPAP has been used
to try and help with the dyspnoea).
Problems with a large bronchopleural fistula on ICU
Difficult to wean from a ventilator.
Hypoxia and hypercapnia result from inability to maintain alveolar
ventilation.
Inability to apply PEEP.
Failure of lung re-expansion.
May need dual ventilation (two ventilators).
May need high frequency ventilation.
High mortality.
What features would you particularly look for in the pre-operative
assessment if a patient with a fistula needs to come to theatre?
Often, the patient will have undergone lung surgery in the previous few days
and a review of the anaesthetic chart is essential.
Airway – Information such as laryngoscopy grade and the size and ease of
placement of the double lumen tube are invaluable.
Breathing – An arterial blood gas would help assess respiratory compromise.
A chest X-ray may show loss of pneumonectomy space fluid and often
collapse or consolidation in the remaining lung.
Circulation – Resuscitation is often required. The patient may be septic.
Most of the patients needing surgery have had failed medical treatment
with a chest drain and antibiotics.
The patency of any chest drain should be established. A new drain may
need to be inserted.
Sometimes, the BPF will be amenable to treatment (glue) via bronchoscopy,
which may avoid the need for anaesthetic.
This should be discussed with the surgical team.
What are the principles in providing anaesthesia?
- Involve an experienced thoracic anaesthetist – these are difficult cases.
- Protect the good lung from becoming soiled by infected material ‘spilling
over’ from the affected side. Sit the patient upright as much as can be
tolerated. - Avoid ventilation until the good lung is isolated.
- A double lumen tube will be required to ventilate both lungs independently
and to protect the BPF from positive pressure, which will worsen the leak. - The double lumen tube (DLT) should be inserted into the ‘good’ side, i.e.
avoiding any surgical sutures. - TIVA would avoid the potentially unreliable delivery of volatile agents on
one lung anaesthesia with a large leak. - Close co-operation with the thoracic surgeon is essential. If the airway is
difficult, they may be able to ventilate the patient with the rigid
bronchoscope down the good side. It is likely the patient will have had a
previous rigid bronchoscopy. - The patient should be extubated as soon as possible,
as ‘negative pressure’ ventilation is preferable. - A thoracic epidural along with short acting anaesthetic agents
will help achieve a prompt wake-up with good analgesia.
How would you anaesthetise this patient?
- Establish appropriate monitoring (including an arterial line), i.v. access and
site a thoracic epidural if thoracotomy is planned. - Pre-oxygenation with the patient as upright as possible.
- If an easy intubation is anticipated,
then following i.v. induction with alfentanil and propofol
and muscle relaxation with suxamethonium,
a double lumen tube (DLT) should be inserted into the ‘good’ lung.
If time permits, the position should be verified immediately
using a fibre-optic bronchoscope.
Once the endobronchial cuff is inflated and the lungs
isolated, IPPV can be commenced via the endobronchial lumen.
- TIVA as maintenance with intermittent boluses of non-depolarizing muscle
relaxant. - In the presence of a difficult airway, other options would include
endobronchial intubation with a normal ETT into the good lung with a
fibre-optic scope or using a rigid bronchoscope to either jet ventilate the
good side, endobronchially intubate the good side or place an
endobronchial blocker into the affected side. - Anaesthesia for a BPF is classically described in textbooks with either awake
endobroncial intubation with topical analgesia of the airway, or
inhalational induction and intubation under deep volatile anaesthesia. Both
of these methods are difficult (especially in a compromised patient) and
when dealing with bulky DLTs.
How would you insert a DLT into a patient with a difficult airway?
You are doing very well if you get on to this question!
One technique that has been described firstly involves awake fibre-optic
intubation with a single lumen tube through the topically anaesthetised
nose and upper airway.
Once general anaesthesia is induced, the DLT is mounted on the fibre-optic
scope which is then repassed via the mouth. Once the fibre-optic scope is in
the trachea alongside the nasal ETT, then the nasal tube’s cuff can be
deflated and the tube withdrawn slightly to allow the DLT to be railroaded
into the trachea.
The final position can be checked with the fibre-optic scope.
