Assistive Devices for Coughing
It is very important to keep your airway clear when you have Duchenne. Secretions in your airway can impair your breathing, preventing oxygen from getting in and prevent carbon dioxide from getting out. Secretions can also fall into your lungs, collecting bacteria and sometimes resulting in pneumonia. The body normally clears the airway by coughing. In Duchenne, the muscles needed to produce an effective cough (the diaphragm and the tiny muscles between the ribs) weaken. If your cough is becoming weaker, it is important that you assist your cough and keep your airway clear.
Coughing is how you clear your lungs and airway, keeping germs and other toxins out of your respiratory tract. This video explains all that is involved when your body coughs, and why coughing is important.
Effective assisted cough techniques should be taught early, certainly when peak cough flow (PCF) falls below 300 L/min and/or used during a respiratory illness. A cough peak flow <27 L/min is an indication that using an assisted cough method is needed even when you are not sick. For more information regarding cough assist and surveillance of pulmonary function, please visit PPMD’s Care for Lung Muscles section.
When children with Duchenne are younger, cough is often normal until a respiratory infection sets in. For that reason, it is important to know how to use assist a cough before there is a respiratory illness or crisis. Please ask your pulmonologist and/or respiratory therapist about assisting a cough before you need to.
Video: Assisted Cough
Over time, the muscles that help you cough may become too weak to cough effectively. Mucous containing germs and other toxins can remain in your lungs, causing you to get sick more easily. If you cough becomes too weak to remove this mucous from your lungs and airways, you will need some help coughing. This video explains the different ways that your cough can be assisted, keeping your airways clean and your lungs health.
The Vest, or high frequency chest wall oscillation, is a technology employing an inflatable vest connected by an air hose to a pulse generator. The Vest rapidly inflates and deflates, applying gentle pulsed pressure to the chest wall. The aim is to generate “shearing force” between the mucus and the lining of the airways, with the intention of dislodging these secretions that can subsequently be coughed and cleared.
Vest therapy is ideal for patients who have conditions with abnormally thick mucus (such as cystic fibrosis, COPD, chronic bronchitis, etc). Patients with respiratory muscle weakness, however, do not typically have abnormally thick mucus. Their difficulty lies in the inability to clear mucus of normal consistency. Therefore, vest therapy is rarely appropriate for patients with Duchenne. Its use may be instituted during the recovery of an extensive pneumonia or if there is a stubborn area of collapse within a lung. Your pulmonologist will let you know if and when it might be appropriate to use the vest.
Mechanically Assisted Cough
Using a cough assist is appropriate for all patients. New assisted cough machines are small, lighter, and convenient for home and travel. The mechanically assisted cough, or cough assist machine uses a facemask, mouthpiece, or tracheostomy to deliver gradual positive air pressure to the airway (inflation), followed by a rapid shift to negative air pressure (deflation), in an attempt to simulate
a natural cough. As patients with Duchenne have difficulty clearing secretions from their airway, a cough assist is not only appropriate therapy, but is critical for maintaining pulmonary health and reducing the incidence of infections and pneumonias. There are several different types of mechanical cough devices are available. These machines need to be calibrated appropriately for the patient using them – please be sure to ask for instruction about how to use this machine when the machine is delivered to your home. Your pulmonary team will help you to find the best device for you.
Some pulmonologists recommend using the machine prophylactically to preserve lung function. This process (called “breath stacking”) may prevent areas of collapse in lungs (called “atelectasis”) and help with chest wall to stay flexible. PPMDs pulmonary webinar series can help to answer questions about breath stacking, as well as other recommendations for pulmonary carel.
Manually Assisted Cough
A cough can be assisted manually, either by using an Ambu bag or by having a person take “frog breaths” to hyper-inflate (over-fill) their lungs. After the lungs are hyper-inflated, a second person can assist the expulsion of air, by performing either abdominal thrusts or thoracic squeeze. Because the abdomen is being pushed, always practice abdominal thrusts when the stomach is empty! The manually assisted cough method may not be as effective as the mechanically assisted cough method, and may be more difficult if the person has scoliosis or chest wall contractures. In addition, it can be somewhat complicated to learn. However, if no mechanically assisted cough is available, this can be life saving for a person with Duchenne. It is quite possible to cause injury by performing manually assisted cough. Because it is very is important to do abdominal thrusts correctly — do not do this before you have received instruction from your pulmonary team!
For more pulmonary-related care information, please visit PPMD’s Care for Lung Muscles section.