Cough Assist Machine – A Clinical Perspective Jonny Smith

Cough assist (or Mechanical Insufflation-Exsufflation) is a chest clearance device which uses negative air pressure to simulate a functional human cough. The machine works by delivering a preset 'breath in', or inhalation, which fully inflates the lungs and moves air behind secretions. It then rapidly switches to a preset 'breath out', or exhalation, which draws secretions mouthwards to be cleared from the chest. This is typically performed through a mouthpiece or mask and the newer machines have various settings to tailor the treatment to the individuals.

Chest infections can be extremely dangerous, particularly if you are unable to clear your chest effectively. Regular use of a Cough assist prevents accumulations of secretions within the chest, which in turn removes favourable conditions for bacteria to multiply and helps to prevent chest infections. In addition, in the event of a chest infection, the cough assist removes infected secretions to clear the airways and improves breathing - just like a functional human cough!

Individuals may require a cough assist when they have weak respiratory muscles - those such as the diaphragm, muscles of the ribs and abdominals - and can no longer effectively clear their chests independently. The guidance for individual need of a cough assist is contained within the British Thoracic Society guidance on Neuromuscular Conditions, which was published in 2012. Cough assist machines are becoming much more widely used because of the advantages they confer over other chest clearance options (such as suction or manual-assisted coughing) with relatively few drawbacks. The most effective method of using a cough assist device is to use it every day, even when you are feeling well, to fully inflate the lungs, keep secretions moving and prevent issues such as chest infections from ever occurring.

If you feel your cough is weak, or has weakened recently, to the point where you are unable to effectively clear your chest, you should alert your physiotherapist or specialist clinician as you may be in need of respiratory support. Even if you feel capable of clearing your chest when you are not unwell, the effects of infection and repeated coughing can leave you fatigued and adversely affect your cough strength. As always, prevention is better than cure! And it is better to have &
rarely need, than rarely need & not have!