Question 3

Created on Fri, 09/01/2017 - 00:55
Last updated on Thu, 12/07/2017 - 03:39
Pass rate: 49%
Highest mark: 7.5

Other SAQs in this paper

Other SAQs on this topic

A 76-year-old male returns to the ICU following a right sided thoracotomy and right upper lobectomy. He is extubated but has a large air leak from the intercostal catheter.

a) Describe your assessment and specific management of the air leak. (50% marks)

b) The patient desaturates and requires re-intubation. Describe your management of his ventilation (50% marks)

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College answer

  1. Describe your assessment and specific management of the air-leak.                          
    • History: discuss with the surgeon and anaesthetist the intraoperative course and any airleak at the end of the operation
    • Assess his respiratory state-respiratory rate and pattern, saturations and oxygen. Support this as indicated but with awareness that re-intubation and PPV will likely worsen the airleak
    • Examine the patient-are the drains connected correctly, are they on suction, what is the suction set at, is the suction entraining air through the chest wall?

Investigations: ABG and urgent CXR

Management:

    • Assess the degree of right lung expansion on the postoperative CXR 
    • Consider removing or reducing the suction on the drain if lung expanded
    • If lung not expanded check icc patency and insert another icc if needed
    • Discuss with the surgeon any operative interventions         
  1. The patient desaturates and requires re-intubation. Describe your ventilatory management.
    • High ventilation pressures will worsen any air leak so low to no PEEP, low peak airway pressures and toleration of hypercarbia
    • Spontaneous patient triggered ventilator modes with pressure support may reduce the airleak compared with mandatory modes
    • Consider: 
      •  Potential need for lung isolation/bronchial blocker 
      • Oscillation
      • ECMO

Examiners comments:  

Many candidates answered part A as if the patient was already intubated, having not read the stem carefully. Very few referred to suction on the drain, or principles in managing broncho pleural fistula. There was little emphasis on additional drains and importance of try to reinflate lung.

Discussion

Assessment and specific management of this air leak would have to involve some answer to the question,  "does this patient need to go back to the operating theatre?". 

Possible causes of air leak: there are only two. 

  • It's coming from the patient's lung
  • It's coming from the extrathoracic air

First, assess the patient to ensure they are safe:

  • Ensure that they are not in respiratory distress (examine them and assess respiratory rate, pulse oximetery, subcutaneous emphysema, tracheal deviation, etc) - look for immediately lifethreatening issues first.
  • Ensure normoxia and normal metabolic parameters (perform ABG )
  • Assess for haemoptysis (an early feature of operative site breakdown)

Second: equipment issues can be easily excluded: the first step will be to examine the chest drain and ensure that all of the side holes are inside the chest.

Third: If the chest drain is mechanically intact (i.e not tracked) truly well inside the chest,  it is bubbling significantly because there is really an air leak from some respiratory structure into the pleural cavity. This could be because of:

  • The operative site leaking (i.e. the bronchus of the right upper lobe)
  • A new pneumothorax from the remaining lung
  • Air gaining entry through the thoracotomy wound

Further assessment would then consist of:

  • Quantification of the leak:
    • Ask the patient to cough
    • Ask the patient to speak
    • Observe the quantity of bubbles.
    • If bubbling is constantly happening while the patient is speaking, the leak is significant.
    • If the bubbling is only present with cough and diminishes with ssutained coughing, the leak is probably small. 
  • CXR to confirm drain position and assess the size of the pneumothorax; and if this is equivocal or uninformative, a chest CT to clearly define the structures and help surgical planning

Management options would consist of:

  • Do nothing. Keep the drain on suction and wait for it to settle down. Most do within 3 days of the surgery. Generally, about 50% of post-lobectomy patients will have some sort of air leak postoperatively, but this tends to settle down by day 3 or so. 
  • Decrease the level of suction. Cerfolio et al (1998) dropped the suction down from the usual 20cm H2O down to 10cm H2O if there was airt leak on Day 2.
  • Provocative chest drain clamping: the air leak may settle down more easily if the pressure in the pleural space is less negative.
  • Permissive chest tube removal: essentially an irreversible alternative to clamping the chest drain; the advantage is that by doing this one eliminates another hole in the chest cavity which might be bringing in extrathoracic air. 
  • Outpatient management with a chest tube and a Heimlich valve is a legitimate option for patients unsuitable for further surgery.
  • Talc pleurodesis  (60ml of a water/talc slurry is injected via the chest drain) Alternative agents mentioned in the literature included tetracycline and silver nitrate.
  • Blood patch is an alternative to talk, but is not as sclerosant. 
  • Pneumoperitoneum  is an option (actually a preventative measure which is most effective when performed intraoperatively) immediately following lobectomy. 
  • Intrabronchial valve which is placed bronchoscopically. It is invasive, has the potential to dislodge, and can act as a nidus for infection. Moreover, you'd need to remove it a few weeks later.
  • Surgical revision is the ultimate solution for a leak which is not resolving with conservative measures in a patient suitable for surgery. The most aggressive solution (hopefully avoidable) would be a pneumonectomy. 

Ventilatory management of a patient with bronchopleural fistula follows a standard set of principles:

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.

Mueller, Michael Rolf, and Beatrice A. Marzluf. "The anticipation and management of air leaks and residual spaces post lung resection." Journal of thoracic disease 6.3 (2014): 271.

Cerfolio, Robert J., et al. "A prospective algorithm for the management of air leaks after pulmonary resection." The Annals of thoracic surgery 66.5 (1998): 1726-1730.