In a recent web chat, participants discussed the role of respiratory muscle strength training (RMST) in swallowing rehabilitation. The chat was sponsored by Special Interest Group (SIG) 13, Swallowing and Swallowing Disorders (Dysphagia).
By Renee Kiourkas and Christine Sapienza
Participant: What is the difference between expiratory (EMST) and inspiratory (IMST) muscle strength training?
Christine Sapienza: Just as it sounds, inspiratory training works on strengthening the inspiratory muscles, primary and secondary. Likewise expiratory trains expiratory muscles, although there are secondary and important effects on swallow muscles with the expiratory training. The goal is to develop these muscles to generate higher forces to produce higher pressures
Renee Kiourkas: They use two different sets of muscles. Internal intercostals and the external intercostal muscles along with the diaphragm. Expiratory muscle strength training helps to keep air in the lungs longer and allows for better control of breathing for most of our patients with COPD (chronic obstructive pulmonary disease).
Participant: How do you know which device to choose for your facility? I work with both acute medical inpatient caseload as well as adult neuro/voice.
Sapienza: Think of the physiology. What do you want to train? If it is swallow and cough, then expiratory. If it is voice, expiratory. While inspiratory would help, the literatures shows expiratory has the primary positive effect. For vent weaning, inspiratory.
Participant: When do you consider inspiratory and expiratory muscle strength training rather than just expiratory?
Kiourkas: I look at the expiratory muscle strength to measure diaphragm weakness, cough force and air entrainment to help with phlegm and saliva control for patients. Inspiratory muscle strength is very helpful for shortness of breath.
Participant: Can RMST be used with biofeedback?
Sapienza: Yes, it can be used for biofeedback, as the patient is getting direct feedback that they can generate the calibrated pressure on the valve—much like you do when you see yourself move a weight on a weight machine. Patients love it for that very reason.
Kiourkas: RMST can be used in all areas. It is great for biofeedback, as the training helps patients to relax and control the muscles associated with breathing and reduces the panic associated with dyspnea or dysphagia since they have a little more control.
Participant: What is the rationale behind using RMST to treat dysphagia?
Kiourkas: By performing the RMST, you are increasing strength of the muscles that open and close the glottis and the tracheal folds that prevent aspiration from occurring.
Sapienza: The studies have shown that during EMST, not IMST, the suprahyoid muscles are co-contracting and generating greater muscle activity than that exhibited during normal dry or wet swallow, and that the muscle force produced is on par with effortful swallow exercises. The vocal fold adductor muscles also co-contract when you develop high expiratory pressures and the VP port (levator palatine shows increased muscle activation). All positive correlates with the swallow process.
Participant: What are specific co-morbidities that would contra-indicate use of RMST with a patient?
Sapienza: Expiratory: Pregnancy, hiatal hernia, uncontrolled GERD (gastroesophageal reflux disease).
Kiourkas: Tracheostomy, throat surgery, severe mucosal secretions, advanced Bulbar involvement are what I am familiar with from ALS patient population. This is from a respiratory standpoint.
Participant: Are there any contraindications to the use of EMST following cardiac or thoracic surgery?
Kiourkas: I would not perform RMST on these patients until at least six weeks post-surgery. The risk of tearing stitches or increasing the intra-thoracic pressure would need to be addressed on a case-by-case scenario with the physician for respiratory failure issues in post-patient populations.
Participant: What adjustments do you make when RMST leads to mucus in mouth or congestion in ears?
Sapienza: I switch to a scuba mouthpiece attachment. If congestion is in ears, then you need to back down the training pressure or stop the training and have the Eustachian tube function examined.
Kiourkas: From a respiratory view I am happy to see increased mucus in the mouth, because it is out of the lungs. As a respiratory therapist, I will work on helping patients to expectorate the mucus and increase the RMST a little more to help maintain airway clearance.
Participant: Is it better to do EMST/IMST to balance out the muscles? I have both an EMST device and a combination device.
Kiourkas: I do not think it is the same thing as weightlifting 20 pounds on one side and only five on the other side of your body. Both exercises would be beneficial to breathing, but EMST would be more beneficial to speech and dysphagia. It would not hurt you to perform both, but the EMST would increase the muscle strength to help with dysphagia and speech. You will not become weak in inspiratory muscle strength if you only perform expiratory muscle strength.
Participant: Other than the EMST150, are there any other devices can we use with our patients that give use objective data?
Sapienza: The objective data comes from what you measure as an outcome. The device is the trainer. Again, use pressure threshold and then set out to measure the outcomes, a scale, a swallow exam, a cough flow rate, a voice quality, etc.
Participant: How do you establish goals? There are norms for peak cough, is this what you use?
Kiourkas: Respiratory uses cough peak flow to qualify for noninvasive ventilation for ALS and neuromuscular patients. The norms are different for each person. Suggested ranges are used as a guide to assist in determining if the patient is getting worse at subsequent visits. We also use a SNIP (sniffing pressure) when they are extremely weak as a trending tool.
Participant: Would you recommend using RMST in the pediatric population?
Kiourkas: I would. Children are very resourceful, they would learn quickly, and they would enjoy the improved ability to swallow. I do not know how well it could work under the age of 5. In the NICU, they would use CPAP or nasal prongs with end expiratory pressure.
Renee Kiourkas, MS, RRT, RPFT, is a respiratory care practitioner, Rush Pulmonary Function Lab, and adjunct faculty, Department of Cardiopulmonary Sciences, Division of Respiratory Care Program, Rush University Medical Center, Chicago. Renee_d_kiourkas@rush.edu
Christine Sapienza, PhD, CCC-SLP, is the dean of The Brooks Rehabilitation College of Healthcare Sciences, and professor of Communication Sciences and Disorders, Jacksonville University, Jacksonville, Florida. firstname.lastname@example.org