Effect of respiratory muscle training on dysphagia in stroke patients-A retrospective pilot study

The Effect of Respiratory Muscle Training on Swallowing Function in Patients With Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

The improvement of swallowing function after stroke is a significant challenge faced by patients and health care professionals. However, the current evidence synthesis of the effects of respiratory muscle training (RMT) on swallowing function is limited.

OBJECTIVE

To assess the effectiveness of RMT on swallowing recovery in patients undergoing stroke.

METHODS

The CKNI, WanFang Data, PubMed, CINAHL, Web of Science, Embase, MEDLINE, and Cochrane Library databases were searched for studies evaluating RMT interventions' effect on swallowing outcomes. Risks of bias were evaluated using the approach recommended by the Cochrane Collaboration tool and a summary of findings table was generated using the GRADE approach. Outcomes were synthesized using a random-effects meta-analysis model.

RESULTS

RMT interventions reduced the risk of aspiration (SMD = 1.19; 95% CI, 0.53-1.84), the recovery process of water swallowing function (RR = 1.22; 95% CI, 1.05-1.42), and the activity of the swallowing muscles (SMD = 2.91; 95% CI, 2.22-3.61). However, there was no significant effect of RMT on the functional level of oral intake (SMD = 0.70; 95% CI, -0.03 to 1.42).

CONCLUSIONS

RMT can be regarded as an innovative, auxiliary means in the near future to better manage and improve swallowing function, given its improving effect on work outcomes in this review.

Effect of respiratory training on swallowing function in swallowing disorders: a systematic review and meta-analysis

PURPOSE

To determine the clinical efficacy of different respiratory training interventions on swallowing function in patients with swallowing disorders through the systematic review.

METHODS

We reviewed the literature regarding the application of respiratory training therapy in patients with swallowing disorders, followed by a PRISMA search of published literature in five databases (PubMed, Web of Science, The Cochrane Library, CINAHL and EMBASE) in December 2022. Two reviewers performed study selection, quality evaluation, and risk of bias, followed by data extraction and detailed analysis.

RESULTS

A total of six randomized controlled studies with a total sample size of 193 cases were included. Respiratory training improved swallowing safety (PAS (n = 151, SMD = 0.69, 95% CI - 1.11 to - 0.26, I2 = 36, p < 0.001)) and swallowing efficiency [residual (n = 63, SMD = 1.67, 95% CI - 2.26 to - 1.09, I2 = 23%, p < 0.001)] compared to control groups. The results of the qualitative analysis conducted in this study revealed that respiratory training enhanced hyoid bone movement but had no effect on swallowing quality of life.

CONCLUSIONS

Respiratory training interventions may improve swallowing safety and efficiency in patients with dysphagia. However, the level of evidence is low, and there is a limited amount of research on the effectiveness and physiology of this intervention to improve swallowing function. In the future, there is a need to expand clinical studies, standardize measurement tools, and improve study protocols.

Implications for respiratory muscle training in patients with stroke-associated pneumonia: a meta-analysis

PURPOSE

To evaluate the effect of respiratory muscle training on improving lung function in patients with stroke-associated pneumonia.

MATERIALS AND METHODS

A systematic retrieval was conducted using the databases of the Cochrane Library, PubMed, the Web of Science, Embase, ProQuest, and others. Studies involving patients who received respiratory muscle training with/without a breathing trainer and those who adopted routine post-stroke rehabilitation training were included in the systematic review. The statistical analysis was performed using RevMan 5.3 software.

RESULTS

Fourteen studies were included involving 850 patients with stroke. According to the results of the meta-analysis, compared with the control group, there were statistically significant differences in forced vital capacity (FVC) measurements (mean difference (MD) = 0.93, p < 0.0001) and improvement values for FEV1/FVC (MD = 0.65, p < 0.00001) in the experimental group. The FEV1 value was higher in the experimental group than in the control group (MD = 5.89, p < 0.0001). Furthermore, respiratory muscle training was superior to routine rehabilitation training for improving the PImax of patients with stroke (MD = 9.20, p < 0.0001). The patients had better respiratory tolerance after respiratory muscle training intervention (MD = 73.40, p < 0.0001).

CONCLUSIONS

The implementation of respiratory muscle training can improve FVC and FEV lung function indicators, inspiratory muscle strength and the 6-min walk test results in patients with stroke.

Characterizing Swallowing Impairment in a Post-Lung Transplant Population

BACKGROUND

Lung transplant recipients carry significant pre- and post-lung transplant dysphagia risk factors related to altered respiratory-swallow coordination as well as acute injury and decompensation resulting in the acute post-lung transplant recovery period. However, we are only beginning to understand the potential physiological contributors to altered swallowing in this population.

METHOD

A retrospective, cross-sectional, cohort study of post-lung transplant patients was performed. All participants received a modified barium swallow study (MBSS) as part of standard care during their acute hospitalization using the Modified Barium Swallow Impairment Profile (MBSImP) protocol and scoring metric. A combination of MBSImP scores, Penetration-Aspiration Scale (PAS) scores, Functional Oral Intake Scale (FOIS) scores, International Dysphagia Diet Standardization Initiative (IDDSI) scale levels, and the time from lung transplant to MBSS was collected, as well as measures of swallowing impairment and swallowing-related outcomes. Differences in swallowing physiology and swallowing-related outcomes between participants with typical versus atypical PAS were explored.

RESULTS

Forty-two participants met our prespecified inclusion criteria. We identified atypical laryngeal penetration and/or aspiration in 52.4% of our post-lung transplant cohort. Silent aspiration occurred in 75% of those patients who aspirated. Comparing typical versus atypical PAS scores, we found statistically significant associations with laryngeal elevation (Component 8), p < .0001; anterior hyoid excursion (Component 9), p = .0046; epiglottic movement (Component 10), p = .0031; laryngeal vestibule closure (Component 11), p < .0001; pharyngeal stripping (Component 12), p = .0058; pharyngeal total scores, p = .0001; FOIS scores, p = .00264; and IDDSI liquid levels, p = .0009.

CONCLUSIONS

Swallowing impairment resulting in abnormal bolus invasion is prevalent in post-lung transplant patients. Airway invasion in this cohort was related to pharyngeal swallow impairment and resulted in modified oral intake. Our findings help expand upon prior literature, which only reported the incidence of aspiration and pathological laryngeal penetration. Our results suggest that the potential for aerodigestive system impairment and negative sequela should not be underestimated in the post-lung transplant population.

Changes in Cough Airflow and Acoustics After Injection Laryngoplasty

OBJECTIVE/HYPOTHESIS

We explored the following hypotheses in a cohort of patients undergoing injection laryngoplasty: (1) glottic insufficiency affects voluntary cough airflow dynamics and restoring glottic competence may improve parameters of cough strength, (2) cough strength can be inferred from cough acoustic signal, and (3) glottic competence changes cough sounds and correlates with spectrogram morphology.

STUDY TYPE/DESIGN

Prospective interventional study.

METHODS

Subjects with glottic insufficiency secondary to unilateral vocal fold paresis, paralysis, or atrophy, and scheduled for injection laryngoplasty completed an instrumental assessment of voluntary cough airflow using a pneumotachometer and a protocolized voluntary cough sound recording. A Wilcoxon signed-rank test was used to compare the differences between pre- and post-injection laryngoplasty in airflow and acoustic measures. A Spearman rank-order correlation was used to evaluate the association between airflow and acoustic cough measures.

RESULTS

Twenty-five patients (13F:12M, mean age 68.8) completed voluntary cough airflow measurements and 22 completed cough sound recordings. Following injection laryngoplasty, patients had a statistically significant decreased peak expiratory flow rise time (PEFRT) (mean change: -0.03 s, SD: 0.06, p = 0.04) and increased cough volume acceleration (mean change: 13.1 L/s2 , SD: 33.9, p = 0.03), suggesting improved cough effectiveness. Correlation of cough acoustic measures with airflow measures showed a weak relationship between PEFRT and acoustic energy (coefficient: -0.31, p = 0.04) and peak power density (coefficient: -0.35, p = 0.02).

CONCLUSIONS

Our study thus indicates that injection laryngoplasty may help avert aspiration in patients with glottic insufficiency by improving cough effectiveness and that improved cough airflow measures may be tracked with cough sounds.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:S1-S14, 2023.

Dosages of swallowing exercises in stroke rehabilitation: a systematic review

PURPOSE

To investigate the dosages of swallowing exercises reported in intervention studies on post-stroke dysphagia through systematic review.

METHODS

Five electronic databases were searched from inception until February 2022 with reference tracing of included studies. Studies were included, where adults with post-stroke dysphagia received rehabilitative, behavioural swallowing exercises, pre/post outcomes were reported, and intervention dosage was described in detail, including frequency, intensity, time, and type of exercise. Two reviewers independently screened studies and rated quality using ASHA Levels of Evidence tool. Data was tabulated and narratively described.

RESULTS

54 studies were included with a total 1501 participants. Studies included 28 randomised controlled trials, 8 non-randomised controlled trials, 12 pre/post studies, 3 retrospective case controls and 3 case studies. Results showed inconsistent reporting of intervention dosage, with intensity the least consistently reported dosage component. While swallowing intervention was most commonly provided five times per week for four weeks, there was a wide breadth of type, frequency, intensity and duration of swallowing exercises reported. Dosage under-reporting and variation was particularly observed in "standard care" co-interventions or control groups. Study strengths included following PRISMA guidelines, providing a comprehensive review of swallowing exercise methodology and dosages, and including non-English studies. The limitation was lack of meta-analysis due to the heterogeneity of included studies.

CONCLUSIONS

Dosages of swallowing exercises are inconsistently reported and vary significantly in post-stroke dysphagia studies. Results indicate the need for consistent and comprehensive dosage reporting in dysphagia studies, and for further research into evidence-based principles to optimise swallowing exercise dosages.

SYSTEMATIC REVIEW REGISTRATION NUMBER

131294.

Statistical Power and Swallowing Rehabilitation Research: Current Landscape and Next Steps

Despite rapid growth in the number of treatments to rehabilitate dysphagia, studies often demonstrate mixed results with non-significant changes to functional outcomes. Given that power analyses are infrequently reported in dysphagia research, it remains unclear whether studies are adequately powered to detect a range of treatment effects. Therefore, this review sought to examine the current landscape of statistical power in swallowing rehabilitation research. Databases were searched for swallowing treatments using instrumental evaluations of swallowing and the penetration-aspiration scale as an outcome. Sensitivity power analyses based on each study's statistical test and sample size were performed to determine the minimum effect size detectable with 80% power. Eighty-nine studies with 94 treatment comparisons were included. Sixty-seven percent of treatment comparisons were unable to detect effects smaller than d = 0.80. The smallest detectable effect size was d = 0.29 for electrical stimulation, d = 0.49 for postural maneuvers, d = 0.52 for non-invasive brain stimulation, d = 0.61 for combined treatments, d = 0.63 for respiratory-based interventions, d = 0.70 for lingual strengthening, and d = 0.79 for oral sensory stimulation. Dysphagia treatments examining changes in penetration-aspiration scale scores were generally powered to reliably detect larger effect sizes and not smaller (but potentially clinically meaningful) effects. These findings suggest that non-significant results may be related to low statistical power, highlighting the need for collaborative, well-powered intervention studies that can detect smaller, clinically meaningful changes in swallowing function. To facilitate implementation, a tutorial on simulation-based power analyses for ordinal outcomes is provided ( https://osf.io/e6usd/ ).

Obstructive Sleep Apnea and Role of the Diaphragm

Obstructive sleep apnea (OSA) causes multiple local and systemic pathophysiological consequences, which lead to an increase in morbidity and mortality in patients suffering from this disorder. OSA presents with various nocturnal events of apnoeas or hypopneas and with sub-clinical airflow limitations during wakefulness. OSA involves a large percentage of the population, particularly men, but the estimate of OSA patients could be much broader than data from the literature. Most of the research carried out in the muscle field is to understand the causes of the presence of chronic nocturnal desaturation and focus on the genioglossus muscle and other muscles related to dilating the upper airways. Sparse research has been published regarding the diaphragm muscle, which is the main muscle structure to insufflate air into the airways. The article reviews the functional anatomy of the muscles used to open the upper respiratory tract and the non-physiological adaptation that follows in the presence of OSA, as well as the functional anatomy and pathological adaptive aspects of the diaphragm muscle. The intent of the text is to highlight the disparity of clinical interest between the dilator muscles and the diaphragm, trying to stimulate a broader approach to patient evaluation.

Stress Resilience Program for Health Care Professionals During a Pandemic: A Pilot Program

BACKGROUND

The COVID-19 pandemic has led to increased burnout and staff turnover for health care providers (HCPs). The purpose of this pilot study was to evaluate the safety and acceptability of a Stress Resilience Program (SRP) for reducing perceived stress and improving resilience among HCPs during a pandemic.

METHOD

Of the 12 HCPs expressing interest in the study, 10 were enrolled in this study. Participants attended three in-person visits (consent/screen, baseline, and end-of-study). The SRP consisted of education related to resilience enhancement and a breathing device (BreatherFit®) for combined respiratory muscle training (cRMT). Participants completed 4 weeks of cRMT and applied situational breathing strategies as needed. Outcomes measured were changes in stress (PSS-10), resilience (BRS), depression (PRIME-MD), and sleep (PSQI and Ōura Ring®).

FINDINGS

The majority of participants were male (60%) and White (60%) with an average age of 39.7 years. Changes from baseline to end-of-treatment indicated a positive trend with significant stress reduction (-3.2 ± 3.9, p = .028) and nonsignificant depression reduction (-0.5 ± 0.7, p = .05). Resilience was high at baseline and continued to stay high during the study with a nonsignificant increase at end-of-study (+0.07 ± 0.7, p = .77). No changes in overall sleep scores were noted. All participants agreed the study was worthwhile, 80% indicated they would repeat the experience, while 90% indicated they would recommend the study to others.

CONCLUSION/APPLICATION TO PRACTICE

Because of its size and portability, SRP is an easily applicable and promising option for reducing stress among HCPs during a high-stress period, such as a pandemic. Larger studies are needed.

Correlation between Forced Vital Capacity and the Severity of Frailty-Induced Dysphagia

Introduction: Frailty syndrome is a complex condition characterized by the gradual deterioration of an individual’s physical, mental, and social functions. Dysphagia is a dysfunction triggered by frailty. However, in patients with frailty syndrome, dysphagia is often undermined, and a proper evaluation is not performed. Therefore, we tried to identify the factors that can provide proper information regarding dysphagia in the frail population. Methods: Patients with dysphagia were divided into those with frailty-induced dysphagia and those with brain-lesion-induced dysphagia. Factors related to the participants’ pulmonary function test (PFT) results were evaluated. The severity of dysphagia was evaluated by determining modified videofluoroscopic dysphagia scale (mVDS) and penetration−aspiration scale (PAS) scores based on videofluoroscopic swallowing studies. Statistical analysis was performed to determine the correlation between PFT results and the parameters indicating dysphagia severity. Results: Multivariate logistic regression analysis revealed that forced vital capacity (FVC) was significantly correlated with mVDS scores in frailty-induced dysphagia (p < 0.05). However, no such significance was detected in brain-lesion-induced dysphagia (p ≥ 0.05). Conclusion: FVC was correlated with the severity of dysphagia (mVDS scores) in patients with frailty-induced dysphagia. Thus, serial FVC-based follow-up can be helpful for understanding patients’ dysphagia status. However, studies with a general population of patients with frailty-induced dysphagia are needed for definite generalization.

Using Ultrasound to Document the Effects of Expiratory Muscle Strength Training (EMST) on the Geniohyoid Muscle

Expiratory muscle strength training (EMST) is an exercise program designed to strengthen the muscles of expiration by increasing expiratory load during breathing exercises using either resistive or pressure threshold devices. Previous research has shown that EMST may increase submental suprahyoid muscle activity as measured with surface electromyography. The impact of EMST on submental muscles is of interest to those who treat dysphagia. The purpose of this study was to determine whether the cross-sectional area of the geniohyoid muscle changes as observed with ultrasound during a 5-week EMST program performed at 75% of maximum expiratory strength using the EMST150 device in healthy adults. Ten healthy adults participated in the 5-week program. Maximum expiratory pressure (MEP) and cross-sectional area of the geniohyoid muscle were measured weekly. Geniohyoid cross-sectional area was measured from ultrasound images recorded in the coronal plane. Repeated Measures ANOVA was used to determine whether there were significant changes among the dependent variables over the study period. Both MEP and geniohyoid area increased significantly in response to a 5-week program of EMST. EMST in healthy adults is effective at strengthening the geniohyoid muscle as reflected by significantly increased cross-sectional area measured with B-mode ultrasound. This is the first study to document weekly change in muscle morphology as a result of EMST. Increasing geniohyoid muscle mass and consequent strength through a program of EMST may be beneficial for persons with pharyngeal stage dysphagia resulting from reduced hyolaryngeal elevation, reduced laryngeal closure, or reduced UES opening.

Effect of Combined Respiratory Muscle Training (cRMT) on Dysphonia following Single CVA: A Retrospective Pilot Study

BACKGROUND

Although dysphonia is less prevalent than dysphagia following cerebrovascular accidents, dysphonia does contribute to the burden of disease resulting from stroke. Strengthening muscles of the larynx and respiratory tract through respiratory muscle training (RMT) has proven effective in improving voice after neurological insult. However, approaches to strengthen only the expiratory muscle groups (EMST) dominate the clinical study literature, with variable outcomes. By focusing on exhalation, the contribution of inspiratory muscles to phonation may have been overlooked. This study investigated the effect of combined respiratory muscle training (cRMT) to improve voice function in stroke patients.

METHODS

Recorded data of twenty patients with dysphonia following stroke were allocated to an intervention (IG) or a control group (CG) based upon whether they chose cRMT or not while awaiting pro bono voice therapy services. The intervention group (n = 10) was treated daily with three 5-minute sessions of combined resistive respiratory muscle training for 28 days, while the control group (n = 10) received no cRMT or other exercise intervention. Perceptual and acoustic measurements as well as a pulmonary function test were assessed pre-and post-intervention.

RESULTS

The intervention group demonstrated significant improvements after 28 days of cRMT in peak flow (127%), patient self-perception of voice improvement (84.41%), as well as in five of the six categories of the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V) overall severity (63.22%), breathiness (61.06%), strain (63.43%), pitch range (48.11%) and loudness (57.51%), compared to the control group who did not receive treatment. Furthermore, cRMT also led to significant improvements in maximum phonation time (212.5%), acoustic parameters of vocal intensity, and total semitone range (165.45%).

CONCLUSIONS

This pilot study shows promise of the feasibility and effectiveness of cRMT to lessen the signs and symptoms of dysphonia while simultaneously improving breath support.