Battling a new and unknown Covid-19 virus over the last year resulted in challenges across healthcare settings. Patients were left with severe debility following prolonged admissions requiring multiple medical interventions. New York City (NYC) was an epicenter of the COVID-19 outbreak during the spring of 2020. Therapists around the country were faced with the same question: “What tools can we use to help our patients recovery while maintaining safety?” This post is a discussion of our decision making process surrounding the use of Respiratory Muscle Strength Training (RMST) with individuals recovering from Covid-19 and includes a single case discussion on how RMST was implemented to support recovery
Respiratory Muscle Strength Training: Why, When, How?
The Speech Language Therapy department at NYU Langone Medical Center had initiated a RMST program prior to the onset of the Covid-19 pandemic on our acute and inpatient rehabilitation units. The RMST program was suspended when Covid -19 hit the New York area. But as we continued to see patients recovering with severe respiratory deconditioning and generalized weakness, we felt strongly that respiratory muscle strength training could be an effective tool to aide in the rehab process. Integration of RMST into treatment made sense given the constellation of symptoms the Covid-19 population presented with including:
- Impaired respiratory strength and endurance
- Reduced cough strength and secretion clearance
- High prevalence of tracheostomies and supplemental oxygen needs
- Oropharyngeal dysphagia with reduced airway protection and reduced bolus clearance
- Impaired functional communication secondary to reduced breath support
- Vocal cord paresis/paralysis
Inspiratory muscle strength training (IMST) targets the muscles of inspiration, strengthens the force of the diaphragmatic contraction, improves vocal fold movement patterns, and assists with vent weaning. Expiratory muscle strength training (EMST) targets the muscles of expiration with empirical outcomes indicating improved cough strength, improved airway protection, and improved vocal loudness and self-perception of improved voice function. Research demonstrates improved velopharyngeal closure, increased submental activation, hyolaryngeal elevation, upper esophageal opening during critical swallow events, laryngeal framework lift and pharyngeal shortening enhancing the oropharyngeal swallow physiology . (1, 2, 3, 4, 5). We continued to receive many patients post-Covid-19, and after discussion with our hospital Infection and prevention control teams and medical director, the program was restarted for patients who met the criteria for being Covid-19 recovered in conjunction with therapists utilizing appropriate personal protective equipment (PPE) for aerosol generating procedures including an N95 and face shield.
Rabbi Greenberg is a 67 year old husband, father, grandfather and teacher who, prior to September of 2020, was in overall good health with no significant medical history. However, like so many others, he developed shortness of breath in September of 2020 and tested positive for COVID-19. His respiratory status declined rapidly, requiring hospitalization with intubation, tracheostomy, and eventual transition to extracorporeal membrane oxygenation (ECMO). His course was complicated, but he stabilized and was able to transition to inpatient rehabilitation by late December of 2020, after a 3 month acute care stay. He presented to the inpatient rehabilitation unit with profound ICU (intensive care) neuropathy, ICU delirium, tracheostomy with the continued need for supplemental O2 via trach collar, and severe oropharyngeal dysphagia with alternate means of nutrition and hydration following assessment via a Fiberoptic endoscopic evaluation of swallowing (FEES).
Therapy goals were varied but included improving respiratory strength and endurance for secretion clearance, functional communication, trach weaning, and improving oropharyngeal swallow function to target his self-stated goal of safely resuming eating and drinking.
Rabbi Greenberg’s cognition improved early in his admission, his vitals began to stabilize, and he progressed to tolerate daytime tracheal occlusion with a Passy Muir Speaking valve. A videofluroscopic swallow study (VFSS) was completed at the end of December 2020, which revealed a moderate oropharyngeal dysphagia characterized by impaired timing and generalized oropharyngeal weakness resulting in reduced airway protection, impaired bolus clearance, and aspiration of thin liquids. He was initiated on a PO diet (food by mouth) of nectar liquids with minced and moist solids and tolerated small quantities. He initially required increased O2 supports and rest breaks with intake due to fatigue. His course was complicated by a change in cognitive status and work up revealed an ileus and suspected onset of pneumonia requiring return to non-oral feeding (NPO) status. After discussion with the medical team, RMST was initiated to help improve oropharyngeal strength and endurance. At this time, Rabbi Greenberg was tolerating capping trials with speech therapy, but continued to have periods of desaturation during mobility requiring removal in both physical and occupational therapy. Maximal inspiratory and expiratory pressures were measured to establish a baseline level of function, both falling well below the normal range for age and sex (MIP= 19 cmH20, MEP= 23 cmH2O). Therapy was initiated with pressure threshold trainers set to 80% of maximal pressures with close monitoring of his vitals signs. Initially, Rabbi Greenberg required frequent rest breaks and cues for pacing to help prevent tachycardia, but he maintained O2 saturation levels greater than 95% consistently across trials. RMST was utilized over a 45 day period as a component of his therapy program. He was successfully decannulated, was independently clearing secretions, communicating effectively with apparently adequate breath support during that time. He was able to resume teaching via the internet and had continued a regular diet with removal of alternate means of nutrition.
The use of RMST in the Covid-19 population posed unique challenges, specifically given the prevalence of cardiopulmonary compromise resulting in tachycardia and high levels of oxygen support to maintain safe saturation levels. Each case required individual assessment, collaboration with the medical team and close monitoring to ensure safety during use of RMST, but has been well-tolerated in the pool of patients we have implemented it with. Treatment varied among patients, often times initiating use at 50% of maximal inspiratory and expiratory pressures, frequent rest breaks and pacing and/or reduction in the number of trials completed to help compensate for the rapid fatigue and fluctuations in vital signs. Formal assessment of the efficacy of RMST has not yet been achieved in our Covid-19 population. Still, we feel strongly the rationale for use is sound and subjectively believe it has supported and contributed greatly to Rabbi Greenberg’s recovery and so many others on the long road of recovery from Covid–19
- Burkhead, L, Sapienza, C, & Rosenbeck, J. (2007). Strength-Training Exercise in Dysphagia Rehabilitation: Principles, Procedures, and Directions for Future Research. Dysphagia, 22(3): 251-265.
- Laciuga H, Rosenbek JC, Davenport PW, Sapienza CM. (2014). Functional outcomes associated with expiratory muscle strength training: Narrative review. The Journal of Rehabilitation Research and Development, 51: 535-546
- Troche MS. (2015). Respiratory Muscle Strength Training for the Management of Airway Protective Deficits. Perspect Swal and Swal Dis(Dysph), 24 (2), 58-64
- Wheeler KM, Chiara T, Sapienza CM.(2007). Surface electromyographic activity of the submental muscles during swallow and expiratory pressure threshold training tasks. Dysphagia. Apr;22(2):108-16.
- Wheeler-Hegland KM, Rosenbek JC, Sapienza CM.(2008). Submental sEMG and hyoid movement during Mendelsohn maneuver, effortful swallow, and expiratory muscle strength training. J Speech Lang Hear Res. Oct;51(5):1072-87.
About the Authors:
Colleen Frayne, MS, CCC-SLP, BCS-S is a Clinical Specialist working on the acute inpatient rehabilitation unit at NYU Health- Rusk Rehabilitation. She obtained her Bachelor of Arts from Loyola College in Baltimore, MD and Masters of Science from MGH Institute of Health Professions. She completed her Clinical Fellowship at Beth Israel Deaconess Medical Center in Boston, MA where she remained until transitioning to Rusk rehabilitation in 2013. She obtained Board Certification in Swallowing in 2014 and has a clinical interest in dysphagia, complex medical patients and the use of Respiratory Muscle Strength Training (RMST). Colleen.email@example.com
Liat Rabinowitz, MS, CCC-SLP is Program Manager of Speech Language Pathology at NYU Langone Orthopedic Hospital- Rusk Rehabilitation. She has worked in the field of TBI at both at the acute and sub acute level. She teaches as adjunct instructor at New York University- Steinhardt on neurogenic communication disorders. Her primary areas of interest include aphasia, cognitive disorders Linguistic impairments following TBI and disorders of consciousness. She has presented both at the state and national level on TBI related topics/ adult neurogenic communication disorders. Liat.firstname.lastname@example.org