The Passy-Muir Valve

Created on Mon, 07/13/2015 - 02:03
Last updated on Thu, 08/27/2015 - 03:53

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This device was asked about in Question 27.3 from the second paper of 2011. A more detailed exploration is carried out in  a chapter dedicated to the Passy-Muir Valve from the Mechanical Ventilation section. In brief, it is a one-way valve which allows a uni-directional movement of air across a tracheostomy with an inflated cuff. Exhaled air comes out through the upper airway, allowing speech, expectoration of secretions, and a more effective cough.

Indications for use

  • Enabling speech in a tracheostomy patient
  • Enabling forceful expectoration of upper airway secretions in a tracheostomy patient
  • Decreasing the risk of aspiration in a patient with a cuff-down tracheostomy

This device prevents the need to finger-block one's tracheostomy each time one is inclined to speak or spit.

Contraindications for use

  • Inflated (or foam filled) tracheostomy cuff (you wont be able to exhale)
  • Absence of a cuff leak with tracheostomy cuff deflated (you wont be able to exhale)
  • Thick uncontrolled tracheal secretions (you will clog the valve)
  • Thick uncontrolled oral secretions (you need to swallow those, or they will get inhaled)
  • Severe respiratory weakness (you will not be able to overcome the valve resistance to inspiration)
  • Unconsciousness (You cant deflate the cuff in these people)
  • Gas trapping with autoPEEP (the valve will increase PEEP)

Complications of use

  • The valve may block
  • If the upper airway fails, you wont be able to exhale
  • A good cough can dislodge the valve, sending it across the room
  • Work of breathing may increase
  • A small amount of apparatus dead space is added



Dettelbach, Mark A., et al. "Effect of the Passy‐Muir valve on aspiration in patients with tracheostomy." Head & neck 17.4 (1995): 297-302.