Selective Lung Ventilation

Reviewed and revised 3 September 2015

OVERVIEW

• Selective Lung Ventilation involves the isolation of one lung from the other allowing independent ventilation.
• Usually performed with a double lumen tube (DLT); alternatives are the use of a univent tube or an endobronchial blocker

RATIONALE

Anatomical lung separation

• Massive hemoptysis (protect normal lung from blood)
• Whole lung lavage for pulmonary alveolar proteinosis (lavage worst lung first)
• Copious secretions (e.g. bronchiectasis, lung abscess) (protect normal lung from pus)

Physiological lung separation

• Unilateral parenchymal injury:
  — Aspiration
  — Pulmonary contusion
  — Pneumonia
  — Unilateral pulmonary edema
• Single lung transplant (post operative complications)
  — e.g. COPD patient with lung transplant requiring different ventilation strategies for each lung
• Bronchopleural fistula
  — allow ventilation of normal lung without worsening leak through fistula
• Unilateral bronchospasm
• Thoracic surgery e.g. pneumonectomy
  — right-sided DLT only used if left pneumonectomy or surgery on left main bronchus

DOUBLE LUMEN TUBES

• right or left depending on bronchus they are designed to intubate
• right sided tubes have a slit to be positioned to facilitate ventilation of RUL
• size = external diameter of tube (French Gauge – 26-41 Fr)
• males; 39-41 Fr
• females; 37-39 Fr
• children use bronchial blocker technique
• remember in an emergency (ie. pulmonary haemorrhage) a standard ETT can be advanced into non-diseased lung (a bougie may help facilitate this)

Table below give diameter of bronchus (usually left) measured on PA CXR (magnifies air bronchogram by 10%)

• bronchoscope must be a narrow scope (<4 mm diameter)
• Mallinckrodt; high volume, low pressure cuff, bronchial tube + pilot balloon blue, radioopaque marker stripe running to tip of bronchial lumen

INSERTION

Technique

• ensure lumens are patent and individual cuffs are working
• anaesthetise and paralyse patient
• direct laryngoscopy
• insertion of endotracheal tube with bronchial concave curve facing anteriorly
• as tip passes through larynx rotate the ETT anti-clockwise 90 degrees until resistance met
  1. once trachea cannulated and tracheal cuff just below the vocal cords, inflate tracheal cuff and ensure ventilation of both lungs via inspection and auscultation
  2. check ventilation through bronchial lumen (clamp off gas flow to tracheal lumen at Y connector and open the tracheal sealing cap to air) – inflate bronchial cuff 1mL at a time until leak stops
  3. check whether can isolate other lung via tracheal lumen – close the sealing cap, remove Y connector and ventilate

Trouble shooting techniques include

• use stylet to help place
• using a bougie as an introducer
• using fiberoptic bronchoscope to cannulate bronchus and rail road tube over scope
• clinically check ventilation once changes have been made between normal ventilation and isolated lung ventilation.
• once tracheal cuff below cords, rotate tube towards bronchus that is to be cannulated, turn patient’s head to opposite side, gently slide tube down until resistance felt

INITIATING

• start with typical ventilation settings (FiO2 0.3, TV 6-8 mL/kg)
• if PAW >35cmH2O think: mechanical problem, malposition, obstruction
  adjust ventilator setting to keep PAW <30cmH2O

WEANING TO TWO LUNG VENTILATION

• gently suction non-ventilated lung
• close sealing cap on lumen to non-ventilated lung and remove clamp on Y connector
• manually ventilate to re-expand collapsed lung (may need pressures up to 35-40cmH2O)
• return to two lung mechanical ventilation

PROBLEMS

Problems with DLT /SLV

• creates shunt (blood flow to non-ventilated / collapsed lung) resulting in hypoxaemia
• sizing and placement of DLT can be difficult
• DLT can be easily malpositioned during patient movement or care (e.g. in ICU)
• muscosal ischemia or trauma and tracheo-bronchial stenosis from cuff inflation and repositioning
• risk of bronchial rupture
• expertise required for insertion
• need for skilled and intensive nursing and specialised monitoring
• need ready availability of fibreoptic bronchoscopy

MANAGEMENT OF HYPOXIA DURING SLV

Objectives

1. minimise atelectasis in the ventilated lung
2. minimise shunt in the non-ventilated lung

Approach

• Set initial tidal volume at 10 ml/kg and adjust RR to maintain normocapnia
• Use FIO₂ of 0.5 initially and increase to 1.0 if required
• Ensure proper tube position (auscultate, bronchoscopy)
• suction regularly
• Apply CPAP to the non-ventilated lung to expand it just enough so as not to interfere with the surgery, thus reduce shunt.
• Application of PEEP to the ventilated lung may reduce atelectasis but oxygenation may deteriorate due to increase in shunt through the other lung.
• Oxygenation can be insufflated into the non-ventilated lung via a suction catheter. Alternatively, the non-ventilated lung can be inflated briefly with 100% oxygen periodically.
• Persistent hypoxia that does not respond to the above manoeuvres may require two-lung ventilation with 100% O2. Failing this, clamping of the pulmonary artery (of the surgical lung) should improve oxygenation.

VIDEO

From Dr Gallagher’s Neighbourhood:

References and Links

LITFL

• CCC — Bronchial blocker

Journal articles

• Anantham D, Jagadesan R, Tiew PE. Clinical review: Independent lung ventilation in critical care. Crit Care. 2005;9(6):594-600. PMC1414047.
• Brodsky JB. Lung separation and the difficult airway. Br J Anaesth. 2009 Dec;103 Suppl 1:i66-75. doi: 10.1093/bja/aep262.PMID: 20007992.
• Campos JH, Ueda K. Lung separation in the morbidly obese patient. Anesthesiol Res Pract. 2012;2012:207598. PMC3287015.
• Campos JH. An update on bronchial blockers during lung separation techniques in adults. Anesth Analg. 2003 Nov;97(5):1266-74. Review. Erratum in: Anesth Analg. 2004 Jan;98(1):131. PMID: 14570636. [Free Fulltext]
• Karzai W, Schwarzkopf K. Hypoxemia during one-lung ventilation: prediction, prevention, and treatment. Anesthesiology. 2009 Jun;110(6):1402-11. PMID: 19417615. [Free Fulltext]

FOAM and web resources

• W. John Russel — Insertion of a double lumen tube