Mechanical insufflation-exsufflation, also called a cough assist, cough insufflator, or mechanical cough device, is a non-invasive approach to suctioning, that alternates positive pressure to fill the lungs (insufflation) and negative pressure to pull air out (exsufflation). These cycles mimic a strong cough to help remove mucus when natural coughing is weak.1,2
Coughing is the body’s built-in way of clearing germs, dust, and excess mucus from the airways. A single cough can generate high airflow, fast enough to sweep particles away. When cough is ineffective—because of weak respiratory muscles, neurologic injury, or illness—mucus can build up and increase infection risk.1,2
When coughing is weak due to neuromuscular disorders or spinal cord injury, mucus can build up and increase the risk of infection. This is where Mechanical Insufflation Exsufflation or cough assist is recommended.1,2,3
A mechanical insufflation-exsufflation or cough assist device is designed to use programmed pressure delivery into and out of the lungs, to aid in the clearance of mucus from the upper airways. By alternating between pushing air into the lungs and creating a vacuum to pull air out, the device effectively replicates the body’s action of a strong, productive cough. Therapy can be delivered with a mask, mouthpiece, or tracheostomy adapter, depending on the patient’s needs.
Mechanical insufflation-exsufflation is typically prescribed for people who have trouble clearing mucus because their cough is weak. Most commonly for individuals with neuromuscular diseases or conditions, also spinal cord injuries.1,2,3,5
Selecting the right mechanical insufflation exsufflation system is a critical decision that can significantly impact the efficacy of therapy and the patient’s experience.
Mechanical insufflation-exsufflation (cough assist) is a non-invasive way to help when natural coughing is weak. By understanding how it works, its potential benefits, and safe use under a clinician’s guidance, patients and care teams can make informed choices to support respiratory health.
When used as part of a comprehensive airway-clearance plan, and with therapy settings titrated to the individual using pressure/flow waveforms6,7,8,9,10, cough assist may help increase peak cough flow1,2,3,4,5 and move mucus, which can reduce pulmonary complications.
What is a mechanical cough device?
A non-invasive cough assist system that alternates positive and negative pressure to simulate a strong cough and clear mucus.
How do you use a cough assist device at home?
With a face mask, trach adapter or mouthpiece under clinician-programmed settings. You repeat couch cycles, and rest as instructed.
Is Mechanical Insufflation Exsufflation (MI-E) therapy the same as suctioning?
No. MI-E is non-invasive and uses positive/negative pressure cycles to generate mimic a cough, while suctioning removes mucus via a catheter. Some patients need both, as directed by a clinician.1,2
Who most commonly benefits from MI-E?
People with neuromuscular weakness (e.g., ALS, muscular dystrophy) or spinal cord injury who can’t generate effective peak cough flows. Other use is clinician-directed.1,2,4,5,11
When should assisted cough be considered?
When spontaneous peak cough flow <270 L/min, or when secretions are difficult to clear despite coaching and other airway-clearance techniques.1,2,4,5,11
How are MI-E settings chosen?
Clinicians adjust inspiratory/expiratory pressures and timing while observing pressure/flow waveforms and patient response to optimize peak cough flow and comfort.6,7,8,9,10
Why might lower insufflation and higher exsufflation help in some patients?
Upper-airway/laryngeal behavior can limit pressure transmission; studies show exsufflation pressures transmit differently than insufflation, so a balance (e.g., lower +Pins, relatively higher −Pexp) can improve flow when glottic closure is an issue.4,8