Predicting aspiration in patients with ischemic stroke: comparison of clinical signs and aerodynamic measures of voluntary cough

Hypotussic cough in persons with dysphagia: biobehavioral interventions and pathways to clinical implementation

Cough is a powerful, protective expulsive behavior that assists in maintaining respiratory health by clearing foreign material, pathogens, and mucus from the airways. Therefore, cough is critical to survival in both health and disease. Importantly, cough protects the airways and lungs from both antegrade (e.g., food, liquid, saliva) and retrograde (e.g., bile, gastric acid) aspirate contents. Aspiration is often the result of impaired swallowing (dysphagia), which allows oral and/or gastric contents to enter the lung, especially in individuals who also have cough dysfunction (dystussia). Cough hyposensitivity, downregulation, or desensitization- collectively referred to as hypotussia- is common in individuals with dysphagia, and increases the likelihood that aspirated material will reach the lung. The consequence of hypotussia with reduced airway clearance can include respiratory tract infection, chronic inflammation, and long-term damage to the lung parenchyma. Despite the clear implications for health, the problem of managing hypotussia in individuals with dysphagia is frequently overlooked. Here, we provide an overview of the current interventions and treatment approaches for hypotussic cough. We synthesize the available literature to summarize research findings that advance our understanding of these interventions, as well as current gaps in knowledge. Further, we highlight pragmatic resources to increase awareness of hypotussic cough interventions and provide support for the clinical implementation of evidence-based treatments. In culmination, we discuss potential innovations and future directions for hypotussic cough research.

Sentinels of the airways

Epithelial cells in the larynx and trachea sense harmful cues and trigger protective reflexes.

Neuroendocrine cells initiate protective upper airway reflexes

Airway neuroendocrine (NE) cells have been proposed to serve as specialized sensory epithelial cells that modulate respiratory behavior by communicating with nearby nerve endings. However, their functional properties and physiological roles in the healthy lung, trachea, and larynx remain largely unknown. In this work, we show that murine NE cells in these compartments have distinct biophysical properties but share sensitivity to two commonly aspirated noxious stimuli, water and acid. Moreover, we found that tracheal and laryngeal NE cells protect the airways by releasing adenosine 5'-triphosphate (ATP) to activate purinoreceptive sensory neurons that initiate swallowing and expiratory reflexes. Our work uncovers the broad molecular and biophysical diversity of NE cells across the airways and reveals mechanisms by which these specialized excitable cells serve as sentinels for activating protective responses.

Cough Correlates of Functional Swallow Outcomes in Atypical Parkinsonism

BACKGROUND

Swallow and cough impairments lead to aspiration and reduced clearance of aspirate material. Both behaviors are impaired in Parkinson's disease, but it is unknown whether a similar relationship of dysfunction exists in forms of atypical Parkinsonism (APD). Elucidating this association in APD may lead to early, comprehensive airway protection treatment.

OBJECTIVES

We tested the hypotheses that swallow deficits in APD are associated with impaired cough and that airway protective dysfunction is associated with longer disease duration.

METHODS

Swallowing difficulty was described by 11 participants with APD. Penetration-Aspiration Scale (PAS) and DIGEST scores for thin liquid trials were extracted from medical records of videofluoroscopic swallow study reports. Voluntary and capsaicin induced-reflex cough measures of flow, volume, and timing were analyzed.

RESULTS

While most participants did not have post-swallow residue, ~80% received abnormal PAS scores and reported swallowing difficulty. Those with abnormal PAS scores had lower voluntary cough expired volume (P = 0.037; mean rank difference = 5.0); lower reflex inspiratory flow rate (P = 0.034; mean rank difference = 5.5); and longer reflex expiratory flow rise time (P = 0.034; mean rank difference = 5.5). Higher PAS scores and reduced reflex cough volume acceleration were significantly correlated (r = -0.63; P = 0.04) and longer disease duration predicted larger voluntary cough expired volume (R2  = 0.72) and longer flow rise times (R2  = 0.47).

CONCLUSIONS

As swallow safety worsens, so might the ability to clear the airways with effective cough in in APD; particularly with longer disease duration. Assessing cough in conjunction with swallowing is important for informing airway protection treatment plans in APD.

Pulmonary function in patients with chronic stroke compared with a control group of healthy people matched by age and sex

BACKGROUND

Effects of chronic stroke on pulmonary function are largely unknown.

AIM

To compare lung volumes in people with chronic stroke with a control group of healthy people matched by age and sex, as well as to investigate the relationship between the lung volumes and functional capacity.

METHODS

A cross-sectional study involving people with chronic stroke. Cases were matched to a control group of healthy people. Lung function and the distance walked during the Six-Minute Walk Test (6MWD) were the main outcomes. Independent t-tests were used to compare pulmonary function between groups and the Pearson correlation coefficient was used to assess any relationship between lung volumes and the 6MWD in the stroke group.

RESULTS

Sixty-six participants (24 males in each group; 56.5 ± 15.5 years) were included. People with stroke presented significantly lower lung volumes when compared to the control group. The median of forced vital capacity (FVC) was 79% and peak expiratory flow was 64% of the reference value. The 6MWD was found to be weakly correlated with inspiratory reserve volume (r = 0.39, p = .03) and peak inspiratory flow (r = 0.35, p = .05).

CONCLUSIONS

People with chronic stroke show decreased lung volumes when compared with healthy people and this likely impacts on their functional capacity.

Assessing the effect of transcranial magnetic stimulation on peak cough flow in patients with supratentorial cerebral infarction: A retrospective cohort study

Respiratory dysfunction following supratentorial cerebral infarction leads to pneumonia and is a major cause of mortality. Decreased voluntary cough function impairs the ability to clear mucus or secretions from the airways and increases the risk of aspiration pneumonia. Peak cough flow (PCF) is one of the objective tools for evaluating voluntary cough function. Repetitive transcranial magnetic stimulation (rTMS) could be applied to the respiratory motor cortex to improve respiratory function. Little is known about the effect of rTMS on PCF in patients with supratentorial cerebral infarction during the subacute period. This study aimed to determine whether rTMS treatment could improve PCF in patients with supratentorial cerebral infarction. We retrospectively recruited patients with subacute supratentorial cerebral infarction who underwent a PCF test. The rTMS group received a combination of rTMS treatment for 2 weeks and conventional rehabilitation for 4 weeks. However, the control group underwent only conventional rehabilitation for 4 weeks. PCF tests were performed before and after treatment and the results were compared between the 2 groups. In total, 145 patients with supratentorial cerebral infarctions were recruited. The PCF parameters before and after treatment increased in both the rTMS and control groups. However, the rTMS group showed a greater increase in PCF values compared with the control group. In patients with supratentorial cerebral infarction, the combination of conventional rehabilitation and rTMS in the subacute period may be helpful in improving voluntary cough function compared with conventional rehabilitation alone.

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.

A Decision Guide for Assessing the Recently Extubated Patient's Readiness for Safe Oral Intake

BACKGROUND

Postextubation dysphagia is a known consequence of endotracheal intubation. Several risk factors for postextubation dysphagia have been identified that could be used to help determine which patients should undergo swallowing assessment by an appropriate professional.

LOCAL PROBLEM

At the authors' institution, critical care nurses, health care providers, and speech-language pathology professionals lacked a clear process for referring patients for swallowing assessment after extubation, resulting in inefficiency and confusion. Information to guide their decision-making in this area was needed. To address this need, a multidisciplinary group convened and developed a guide with specific indicators.

METHODS

A review of the literature on postextubation dysphagia was conducted to determine the most appropriate indicators for the guide, which was piloted in the medical intensive care unit. The utilization rate was calculated. Referrals to speech-language pathology professionals were tabulated before and after the project.

RESULTS

During the 11 months before implementation of the project, there were 994 speech-language pathology consultations for postextubation evaluation of swallowing. During the 11 months after implementation, there were 831 consultations, representing a 16.4% reduction. The decline in consultations resulted in cost savings in addition to preventing unnecessary testing before patients' resumption of oral intake. The utilization rate for the guide during the project was 58%.

CONCLUSION

The decision guide was an effective tool to help nurses and health care providers determine which patients should be referred to speech-language pathology professionals for swallowing assessment after extubation, facilitating the appropriate use of limited health care resources.

Post-stroke respiratory complications using machine learning with voice features from mobile devices

Abnormal voice may identify those at risk of post-stroke aspiration. This study was aimed to determine whether machine learning algorithms with voice recorded via a mobile device can accurately classify those with dysphagia at risk of tube feeding and post-stroke aspiration pneumonia and be used as digital biomarkers. Voice samples from patients referred for swallowing disturbance in a university-affiliated hospital were collected prospectively using a mobile device. Subjects that required tube feeding were further classified to high risk of respiratory complication, based on the voluntary cough strength and abnormal chest x-ray images. A total of 449 samples were obtained, with 234 requiring tube feeding and 113 showing high risk of respiratory complications. The eXtreme gradient boosting multimodal models that included abnormal acoustic features and clinical variables showed high sensitivity levels of 88.7% (95% CI 82.6–94.7) and 84.5% (95% CI 76.9–92.1) in the classification of those at risk of tube feeding and at high risk of respiratory complications; respectively. In both cases, voice features proved to be the strongest contributing factors in these models. Voice features may be considered as viable digital biomarkers in those at risk of respiratory complications related to post-stroke dysphagia.

Voluntary Cough Testing as a Clinical Indicator of Airway Protection in Cervical Spinal Cord Injury

OBJECTIVE

Voluntary cough testing (VCT) may be useful for determining aspiration risk in neurogenic dysphagia; however, has yet to be investigated in traumatic cervical spinal cord injury (tCSCI). The study explored if VCT may elucidate swallowing safety and kinematics related to airway protection in tCSCI survivors.

METHODS

Ten inpatients, 13-73 days post-tCSCI (7 incomplete injuries), completed VCT and a modified barium swallowing study that was analyzed via the Penetration Aspiration Scale (PAS) and norm-referenced measures of swallowing events related to airway protection. Spearman rho correlations explored relations among cough airflow, median PAS, and airway protection. Mann-Whitney U tests explored group differences based on clinical airway invasion (PAS > 2) and receiver operating characteristic statistics probed the sensitivity/specificity of VCT measures.

RESULTS

Safe (PAS > 2) and unsafe swallowers differed by cough volume acceleration (CVA) for the total sample and by inspiratory duration for incomplete injuries (p = 0.03, r > 0.7). A cut-off value of 24.8 L/s for CVA predicted airway invasion (AUC = 0.917, p = 0.03) with sensitivity = 100%/specificity = 75%. CVA correlated with delayed laryngeal vestibule closure during swallowing for both the total sample and for incomplete injuries (r_s  > 0.6, p < 0.05). Blunted peak flow and prolonged cough phases were associated with disordered laryngeal kinematics and prolonged bolus transit during swallowing (p < 0.05).

CONCLUSIONS

Reduced CVA, blunted peak flow, and prolonged cough phases reflected PAS and disrupted mechanisms of airway protection in tCSCI survivors, demonstrating promise for VCT as a clinical assessment for post-tCSCI dysphagia.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Laryngeal and swallow dysregulation following acute cervical spinal cord injury

Laryngeal function is vital to airway protection. While swallow is mediated by the brainstem, mechanisms underlying increased risk of dysphagia after cervical spinal cord injury (SCI) are unknown. We hypothesized that loss of descending phrenic drive affects swallow and breathing differently, and loss of ascending spinal afferent information alters swallow regulation. We recorded electromyograms from upper airway and chest wall muscles in freely breathing pentobarbital-anesthetized cats and rats. Inspiratory laryngeal activity increased ~two-fold following C2 lateral-hemisection. Ipsilateral to the injury, crural diaphragm EMG amplitude was reduced during breathing (62 ± 25% change post-injury), but no animal had complete termination of activity; 75% of animals increased contralateral diaphragm recruitment, but this did not reach significance. During swallow, laryngeal adductor and pharyngeal constrictor muscles increased activity, and diaphragm activity was bilaterally suppressed. This was unexpected because of the ipsilateral-specific response during breathing. Swallow-breathing coordination was also disrupted and more swallows occurred during early expiration. Finally, to determine if the chest wall is a major source of feedback for laryngeal regulation, we performed T1 total transections in rats. As in the C2 lateral-hemisection, inspiratory laryngeal recruitment was the first feature noted. In contrast to the C2 lateral-hemisection, diaphragmatic drive increased after T1 transection. Overall, we found that SCI alters laryngeal drive during swallow and breathing, and reduced swallow-related diaphragm activity. Our results show behavior-specific effects, suggesting SCI affects swallow more than breathing, and emphasizes the need for additional studies on the effects of ascending afferents from the spinal cord on laryngeal function.

Japanese clinical practice guidelines for aspiration and pharyngeal residual assessment during eating and swallowing for nursing care

AIM

This clinical practice guideline aims to provide and recommend methods of assessing aspiration and pharyngeal residue during eating and swallowing and methods of selecting and implementing nursing care for adults to prevent the development of aspiration pneumonia through early and appropriate management of oropharyngeal dysphagia.

METHODS

In April 2018, the Japan Academy of Nursing Science established the Supervisory Committee in Nursing Care Development/Standardization Committee to develop clinical practice guidelines for aspiration and pharyngeal residual assessment during eating and swallowing for nursing care. This clinical practice guideline was developed according to the Minds Manual for Guideline Development 2017, with the aim of providing a specific pathway for nurses to determine the policy for selecting management for oropharyngeal dysphagia based on research evidence and multifaceted factors including the balance of benefits and harms and patients' values.

RESULTS

Based on the 10 clinical questions related to assessment by physical assessment, the Repetitive Saliva Swallowing Test, Modified Water Swallowing Test, Food Test, cervical auscultation, observation using an ultrasound diagnostic device, and an endoscope, 10 recommendations have been developed. Eight recommendations have been evaluated as the Grading of Recommendations Assessment, Development and Evaluation (GRADE) 2C, and the other two have been evaluated as no GRADE.

CONCLUSION

The first reliable clinical practice guideline has been produced from an academic nursing organization that focuses on assessment for nursing care and incorporates the latest findings.

Voluntary Cough Effectiveness and Airway Clearance in Neurodegenerative Disease

PURPOSE

Voluntary cough dysfunction is highly prevalent across multiple patient populations. Voluntary cough has been utilized as a screening tool for swallowing safety deficits and as a target for compensatory and exercise-based dysphagia management. However, it remains unclear whether voluntary cough dysfunction is associated with the ability to effectively clear the airway.

METHOD

Individuals with neurodegenerative disorders performed same-day voluntary cough testing and flexible endoscopic evaluations of swallowing (FEES). Participants who were cued to cough after exhibiting penetration to the vocal folds and/or aspiration with thin liquids during FEES met inclusion criteria. One-hundred and twenty-three trials were blinded, and the amount of residue before and after a cued cough on FEES was measured with a visual analog scale. Linear and binomial mixed-effects models examined the relationship between cough airflow during voluntary cough testing and the proportion of residue expelled.

RESULTS

Peak expiratory flow rate (p = .004) and cough expired volume from the entire epoch (p = .029) were significantly associated with the proportion of aspiration expelled from the subglottis. Peak expiratory flow rate values of 3.00 L/s, 3.50 L/s, and 5.30 L/s provided high predicted probabilities that ≥ 25%, ≥ 50%, and ≥ 80% aspirate was expelled. Accounting for depth of aspiration significantly improved model fit (p < .001).

CONCLUSIONS

These findings suggest that voluntary cough airflow is associated with cough effectiveness to clear aspiration from the subglottis, although aspiration amount and depth may play an important role in this relationship. These findings provide further support for the clinical utility of voluntary cough in the management of dysphagia.

Peak Voluntary Cough Flow and Oropharyngeal Dysphagia as Risk Factors for Pneumonia

Objective

To investigate the relationship between voluntary peak cough flow (PCF), oropharyngeal dysphagia, and pneumonia in patients who were evaluated with videofluoroscopic swallowing study (VFSS).

Methods

Patients who underwent both VFSS and PCF measurement on the same day were enrolled retrospectively (n=821). Pneumonia (n=138) and control (n=683) groups were assigned based on presence of pneumonia within 1 month from the date of VFSS assessment. In addition, sex, age (<65 and ≥65 years), preceding conditions, modified Barthel Index (MBI), Mini-Mental State Examination (MMSE), PCF value (<160, ≥160 and <270, and ≥270 L/min), and presence of aspiration/penetration on VFSS were reviewed.

Results

Pneumonia group was more likely to be male (n=108; 78.3%), ≥65 years (n=121; 87.7%), with neurodegenerative (n=25; 18.1%) or other miscellaneous diseases (n=50; 36.2%), and in poor functional level with lower value of MBI (39.1±26.59). However, MMSE was not significantly different in comparison to that of the control group. The pneumonia group was also more likely to have dysphagia (82.6%) and lower value of PCF (<160 L/min, 70.3%). In multivariable logistic regression analysis, male sex (odd ratio [OR]=6.62; 95% confidence interval [CI], 2.70–16.26), other miscellaneous diseases as preceding conditions (OR=2.52; 95% CI, 1.14–5.58), dysphagia (OR=3.82; 95% CI, 1.42–10.23), and PCF <160 L/min (OR=14.34; 95% CI, 1.84–111.60) were factors significantly related with pneumonia.

Conclusion

Impaired swallowing and coughing function showed an independent association with the development of pneumonia. Patients with PCF <160 L/min require more attention with lung care and should be encouraged with voluntary coughing strategy to prevent possible pulmonary complications.

Post-Cerebrovascular Stroke and Early Dysphagia Assessment: A Systematic Review

PURPOSE

We performed a systematic review on the early assessment of swallowing function after cerebrovascular stroke.

MATERIALS AND METHODS

A systematic review of the English language literature of the past 20 years was performed regarding swallowing function and cerebrovascular stroke. All articles reporting swallowing evaluation through clinical examination validated scores, and diagnostic tools were included in the summary.

RESULTS

The systematic review of the literature identified 1,768 potentially relevant studies with 7 papers retrieved with a total of 589 stroke dysphagic patients. While at the clinical neurological assessment, The National Institutes of Health Stroke Scale was more frequently used as a clinical outcome predictor. The Bedside screening approach was carried out in 6 papers to assess patients with probable swallowing disorders. Among the diagnostic tools, seven studies performed the Flexible Fiberoptic Endoscopic evaluation assessing scoring validated system while two papers reported early swallowing outcomes Videofluoroscopic Swallow Study.

CONCLUSIONS

Our systematic review revealed the findings significantly associated with dysphagia in post-cerebrovascular patients. Endoscopic evaluation of swallowing proved to be the most used method in the literature, effective in identifying early predictors of dysphagia. Given the presence of different assessing scores employed and reduced study samples enrolled, further studies with large courts are necessary for a greater significance.

Posterior National Institutes of Health Stroke Scale Improves Prognostic Accuracy in Posterior Circulation Stroke

BACKGROUND AND PURPOSE

The National Institutes of Health Stroke Scale (NIHSS) underestimates clinical severity in posterior circulation stroke and patients presenting with low NIHSS may be considered ineligible for reperfusion therapies. This study aimed to develop a modified version of the NIHSS, the Posterior NIHSS (POST-NIHSS), to improve NIHSS prognostic accuracy for posterior circulation stroke patients with mild-moderate symptoms.

METHODS

Clinical data of consecutive posterior circulation stroke patients with mild-moderate symptoms (NIHSS <10), who were conservatively managed, were retrospectively analyzed from the Basilar Artery Treatment and Management registry. Clinical features were assessed within 24 hours of symptom onset; dysphagia was assessed by a speech therapist within 48 hours of symptom onset. Random forest classification algorithm and constrained optimization were used to develop the POST-NIHSS in the derivation cohort. The POST-NIHSS was then validated in a prospective cohort. Poor outcome was defined as modified Rankin Scale score ≥3 at 3 months.

RESULTS

We included 202 patients (mean [SD] age 63 [14] years, median NIHSS 3 [interquartile range, 1-5]) in the derivation cohort and 65 patients (mean [SD] age 63 [16] years, median NIHSS 2 [interquartile range, 1-4]) in the validation cohort. In the derivation cohort, age, NIHSS, abnormal cough, dysphagia and gait/truncal ataxia were ranked as the most important predictors of functional outcome. POST-NIHSS was calculated by adding 5 points for abnormal cough, 4 points for dysphagia, and 3 points for gait/truncal ataxia to the baseline NIHSS. In receiver operating characteristic analysis adjusted for age, POST-NIHSS area under receiver operating characteristic curve was 0.80 (95% CI, 0.73-0.87) versus NIHSS area under receiver operating characteristic curve, 0.73 (95% CI, 0.64-0.83), P=0.03. In the validation cohort, POST-NIHSS area under receiver operating characteristic curve was 0.82 (95% CI, 0.69-0.94) versus NIHSS area under receiver operating characteristic curve 0.73 (95% CI, 0.58-0.87), P=0.04.

CONCLUSIONS

POST-NIHSS showed higher prognostic accuracy than NIHSS and may be useful to identify posterior circulation stroke patients with NIHSS <10 at higher risk of poor outcome.

A Survey of Speech-Language Pathologists' Experience With Clinical Cough Assessment

PURPOSE

The purpose of this study was to determine if students (clinicians-intraining) and clinicians of speech-language pathology assess cough during clinical swallow evaluations. We also sought to determine if participants received background education and training regarding implementation of clinical cough assessment. Finally, we aimed to identify participant interest in a cough assessment training program.

METHOD

A clinician-researcher panel developed a 20-question survey to address specific aims. The final survey was distributed via social media and a clinical dysphagia website after two phases of revision.

RESULTS

A percentage (84.6%) of the survey participants reported that they assess cough in clinical swallow evaluations, mainly using subjective measures. The majority of clinicians reported no background education or skilled training to implement cough assessment. Background education and training was higher for participants outside the United States, although the total sample size of that group was small. Almost all participants (97.8%) were interested in a cough training program.

CONCLUSIONS

Many practicing clinicians in this survey reported that they complete cough assessments, despite limited education and training to do so. However, they also reported high interest in participating in a clinical cough assessment training program, which would support the field of speech-language pathology and patients at risk of airway protective dysfunction.

Respiratory Muscle Training Reduces Respiratory Complications and Improves Swallowing Function After Stroke: A Systematic Review and Meta-Analysis

OBJECTIVE

To investigate if respiratory muscle training is capable of reducing the occurrence of respiratory complications and improving dysphagia (swallowing or cough function) after stroke?

DESIGN

Systematic review of randomized control trials based on the Cochrane guidelines.

PARTICIPANTS

Patients (> 18 years old) were diagnosed with stroke.

INTERVENTION

Respiratory muscle training aimed at increasing respiratory muscles' strength by using the threshold resistance trainer or flow-oriented resistance trainer.

OUTCOME MEASURES

Respiratory complications, swallowing and cough function.

RESULTS

Eleven trials (n=523 participants) were included . Respiratory muscle training reduced the risk of respiratory complications (RR0.51, 95%CI 0.28 to 0.93, I² = 0%,P=0.03, ARD =0.068, NNT=14.71) compared with no/sham respiratory intervention. It also decreased the liquid type PAS scores by 0.81 (95% CI -1.19 to -0.43, I² = 39%, P<0.0001). There was no significant association between respiratory muscle training and FOIS scores, cough function:increased FOIS scores by 0.47 (95%CI -0.45 to 1.39, I² = 55%, P=0.32), decreased PECF-VC by 18.70 L/min (95%CI -59.74 to 22.33, I² = 19%, P=0.37) and increased PECF-RC by 0.05 L/min (95% CI -40.78 to 40.87 I2 = 0%, P=1.00) .

CONCLUSION

This meta-analysis provided evidence that respiratory muscle training is effective in reducing the risk of respiratory complications, and improving dysphagia by reducing penetration or aspiration during swallowing liquid bolus after stroke. However, there was no sufficient evidence to determine that respiratory muscle training improves cough function. Additional multi-center studies using larger patient cohorts are required to validate and support these findings. Furthermore, long-term follow-up studies should be performed to measure outcomes, at the same time avoiding bias due to confounding factors such as heterogeneity of the etiologies of dysphagia.

European Stroke Organisation and European Society for Swallowing Disorders guideline for the diagnosis and treatment of post-stroke dysphagia

Post-stroke dysphagia (PSD) is present in more than 50% of acute stroke patients, increases the risk of complications, in particular aspiration pneumonia, malnutrition and dehydration, and is linked to poor outcome and mortality. The aim of this guideline is to assist all members of the multidisciplinary team in their management of patients with PSD. These guidelines were developed based on the European Stroke Organisation (ESO) standard operating procedure and followed the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. An interdisciplinary working group identified 20 relevant questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence and wrote evidence-based recommendations. Expert opinion was provided if not enough evidence was available to provide recommendations based on the GRADE approach. We found moderate quality of evidence to recommend dysphagia screening in all stroke patients to prevent post-stroke pneumonia and to early mortality and low quality of evidence to suggest dysphagia assessment in stroke patients having been identified at being at risk of PSD. We found low to moderate quality of evidence for a variety of treatment options to improve swallowing physiology and swallowing safety. These options include dietary interventions, behavioural swallowing treatment including acupuncture, nutritional interventions, oral health care, different pharmacological agents and different types of neurostimulation treatment. Some of the studied interventions also had an impact on other clinical endpoints such as feedings status or pneumonia. Overall, further randomized trials are needed to improve the quality of evidence for the treatment of PSD.

Effect of Capsaicin Atomization-Induced Cough on Sputum Excretion in Tracheotomized Patients After Hemorrhagic Stroke: A Randomized Controlled Trial

Background Timely and effective removal of respiratory secretions is of great significance for tracheotomized patients. The purpose of this study is to investigate the effectiveness of capsaicin nebulization to stimulate cough to promote early clearance of respiratory secretions in tracheotomized patients after hemorrhagic stroke. Method This study implemented a randomized controlled design. Sixty-three patients who were tracheotomized following a hemorrhagic stroke completed this randomized controlled trial. In the control group, 33 cases were given a routine care after tracheotomy. In the intervention group, 30 cases were given a capsaicin solution nebulization in addition to the routine care. The daily sputum output and the number of sputum suctioning were observed. The differences in sputum viscosity, cough function, and Clinical Pulmonary Infection Score (CPIS) were compared between the two groups before and after the intervention. Vital sign changes during capsaicin nebulization and suctioning were compared between the two groups in a pilot study. Results The daily sputum output of the capsaicin intervention group was significantly higher than that of the control group (p < .05). The number of sputum suctioning of capsaicin group was less than that of the control group after intervention (p < .05). The CPIS score of the capsaicin group was lower than that of the control group (p < .05) after a 1-week intervention. Patients' heart rate, respiratory rate, and oxygen saturation during capsaicin nebulization were not statistically different from those during routine sputum suctioning (p > .05). Conclusions Capsaicin atomization-induced cough can effectively promote sputum excretion of hemorrhagic stroke patients undergoing tracheotomy and has a good safety profile. The Clinical Trial registration number of this study is ChiCTR2000037772 (http://www.chictr.org.cns). Supplemental Material https://doi.org/10.23641/asha.16821352.

Screening for aspiration risk associated with dysphagia in acute stroke

BACKGROUND

Stroke can affect people's ability to swallow, resulting in passage of some food and drink into the airway. This can cause choking, chest infection, malnutrition and dehydration, reduced rehabilitation, increased risk of anxiety and depression, longer hospital stay, increased likelihood of discharge to a care home, and increased risk of death. Early identification and management of disordered swallowing reduces risk of these difficulties.

OBJECTIVES

Primary objective • To determine the diagnostic accuracy and the sensitivity and specificity of bedside screening tests for detecting risk of aspiration associated with dysphagia in people with acute stroke Secondary objectives • To assess the influence of the following sources of heterogeneity on the diagnostic accuracy of bedside screening tools for dysphagia - Patient demographics (e.g. age, gender) - Time post stroke that the study was conducted (from admission to 48 hours) to ensure only hyperacute and acute stroke swallow screening tools are identified - Definition of dysphagia used by the study - Level of training of nursing staff (both grade and training in the screening tool) - Low-quality studies identified from the methodological quality checklist - Type and threshold of index test - Type of reference test SEARCH METHODS: In June 2017 and December 2019, we searched CENTRAL, MEDLINE, Embase, CINAHL, and the Health Technology Assessment (HTA) database via the Centre for Reviews and Dissemination; the reference lists of included studies; and grey literature sources. We contacted experts in the field to identify any ongoing studies and those potentially missed by the search strategy.

SELECTION CRITERIA

We included studies that were single-gate or two-gate studies comparing a bedside screening tool administered by nurses or other healthcare professionals (HCPs) with expert or instrumental assessment for detection of aspiration associated with dysphagia in adults with acute stroke admitted to hospital.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened each study using the eligibility criteria and then extracted data, including the sensitivity and specificity of each index test against the reference test. A third review author was available at each stage to settle disagreements. The methodological quality of each study was assessed using the Quality Assessment of Studies of Diagnostic Accuracy (QUADAS-2) tool. We identified insufficient studies for each index test, so we performed no meta-analysis. Diagnostic accuracy data were presented as sensitivities and specificities for the index tests.

MAIN RESULTS

Overall, we included 25 studies in the review, four of which we included as narratives (with no accuracy statistics reported). The included studies involved 3953 participants and 37 screening tests. Of these, 24 screening tests used water only, six used water and other consistencies, and seven used other methods. For index tests using water only, sensitivity and specificity ranged from 46% to 100% and from 43% to 100%, respectively; for those using water and other consistencies, sensitivity and specificity ranged from 75% to 100% and from 69% to 90%, respectively; and for those using other methods, sensitivity and specificity ranged from 29% to 100% and from 39% to 86%, respectively. Twenty screening tests used expert assessment or the Mann Assessment of Swallowing Ability (MASA) as the reference, six used fibreoptic endoscopic evaluation of swallowing (FEES), and 11 used videofluoroscopy (VF). Fifteen screening tools had an outcome of aspiration risk, 20 screening tools had an outcome of dysphagia, and two narrative papers did not report the outcome. Twenty-one screening tests were carried out by nurses, and 16 were carried out by other HCPs (not including speech and language therapists (SLTs)). We assessed a total of six studies as low risk across all four QUADAS-2 risk of bias domains, and we rated 15 studies as low concern across all three applicability domains. No single study demonstrated 100% sensitivity and specificity with low risk of bias for all domains. The best performing combined water swallow and instrumental tool was the Bedside Aspiration test (n = 50), the best performing water plus other consistencies tool was the Gugging Swallowing Screen (GUSS; n = 30), and the best water only swallow screening tool was the Toronto Bedside Swallowing Screening Test (TOR-BSST; n = 24). All tools demonstrated combined highest sensitivity and specificity and low risk of bias for all domains. However, clinicians should be cautious in their interpretation of these findings, as these tests are based on single studies with small sample sizes, which limits the estimates of reliability of screening tests.

AUTHORS' CONCLUSIONS

We were unable to identify a single swallow screening tool with high and precisely estimated sensitivity and specificity based on at least one trial with low risk of bias. However, we were able to offer recommendations for further high-quality studies that are needed to improve the accuracy and clinical utility of bedside screening tools.

Tongue cleaning in the elderly and its role in the respiratory and swallowing functions: Benefits and medical perspectives

Oral dysfunction, including oral uncleanness and decline in tongue motor function, tongue pressure and swallowing function, precedes frailty. The tongue's dorsum is a reservoir of oral microbiota, desquamated epithelial mucosa and leukocytes due to the multi-papillate anatomy, and leads to tongue coating. The tongue coating is frequently found in older adults because of hyposalivation, immunity's hypoactivity, diminished motor function and compromised tongue's pressure with age. Anaerobe-driven volatile sulphur compounds in tongue coating are a major cause of intra-oral malodor. Dysbiosis of the tongue-coating microbiome rather than the amount of microorganisms is associated with a risk of aspiration pneumonia. Daily tongue cleaning with a brush or scraper is an easy way to control tongue coating deposits and quality. Using mouth wash or rinse-containing germicides is also a way to control the microbiota of tongue coating. The tongue function is closely related to swallowing. Tongue and suprahyoid muscles are linked with respiratory muscles through the endothoracic fascia. The mechanical stimulation during the cleaning of the tongue may stimulate the respiratory muscles. An intervention trial revealed that tongue cleaning by mucosal brush improves tongue pressure, swallowing and respiratory function in old residents of nursing homes, suggesting a rehabilitative effect of tongue cleaning on the swallowing and respiratory functions, preventing aspiration pneumonia. This narrative review assesses the tongue-cleaning benefits for respiratory and swallowing functions and the possibility of preventing aspiration pneumonia.

Assessment of cough in head and neck cancer patients at risk for dysphagia-An overview

BACKGROUND

This literature review explores the terminology, the neurophysiology, and the assessment of cough in general, in the framework of dysphagia and regarding head and neck cancer patients at risk for dysphagia. In the dysphagic population, cough is currently assessed perceptually during a clinical swallowing evaluation or aerodynamically.

RECENT FINDINGS

Recent findings have shown intra and inter-rater disagreements regarding perceptual scoring of cough. Also, aerodynamic measurements are impractical in a routine bedside assessment. Coughing, however, is considered to be a clinically relevant sign of aspiration and dysphagia in head and cancer patients treated with concurrent chemoradiotherapy.

CONCLUSION

This article surveys the literature regarding the established cough assessment and stresses the need to implement innovative methods for assessing cough in head and neck cancer patients treated with concurrent chemoradiotherapy at risk for dysphagia.

Global Physiology and Pathophysiology of Cough: Part 2. Demographic and Clinical Considerations: CHEST Expert Panel Report

BACKGROUND

Cough characteristics vary between patients, and this can impact clinical diagnosis and care. The purpose of part two of this state-of-the-art review is to update the American College of Chest Physicians (CHEST) 2006 guideline on global physiology and pathophysiology of cough.

STUDY DESIGN AND METHODS

A review of the literature was conducted using PubMed and MEDLINE databases from 1951 to 2019 using prespecified search terms.

RESULTS

We describe the demographics of typical patients with cough in the clinical setting, including how cough characteristics change across age. We summarize the effect of common clinical conditions impacting cough mechanics and the physical properties of mucus on airway clearance.

INTERPRETATION

This is the second of a two-part update to the 2006 CHEST cough guideline; it complements part one on basic phenomenology of cough by providing an extended clinical picture of cough along with the factors that alter cough mechanics and efficiency in patients. A greater understanding of the physiology and pathophysiology of cough will improve clinical management.

Accuracy of Acoustic Evaluation of Swallowing as a Diagnostic Method of Dysphagia in Individuals Affected by Stroke: Preliminary Analysis

After a stroke, more than half of the patients have some kind of disability, and dysphagia is frequently found. Cervical auscultation by Doppler sonar is an innovative technique with gain of credibility in the clinical evaluation of swallowing. To verify the diagnostic accuracy of Doppler sonar along with the DeglutiSom® software as an auxiliary method in the evaluation of oropharyngeal dysphagia in patients after stroke. The research is a cross-sectional, uncontrolled, blind, quantitative study with systematic random sampling. Patients from inpatient and outpatient units of a reference hospital with a stroke care unit were concomitantly submitted to both Doppler sonar and Fiberoptic Endoscopic Evaluation of Swallowing (FEES®). Seventy-three audio files collected from 26 patients through Doppler sonar were analyzed using DeglutiSom® software and confronted with the FEES® report, regarding three food consistencies offered to them during the exam. The study showed that the Doppler sonar correctly identified, among all the analyzed files, those that actually presented tracheal aspiration as well as it effectively identified patients who did not aspirate. The Youden index of 0.91 corroborates this information, showing a promising accuracy in detecting tracheal aspiration in the studied sample. The study evaluates the diagnostic accuracy of Doppler sonar, showing that it can be used as a valuable tool in the diagnosis of tracheal aspiration in patients after stroke. It is important to emphasize that the identification of residue by this method requires further studies. Also, larger sample size and more than one blind evaluator should be considered in future researches to increase the reliability of the proposed method.

Objective measurement of acoustic intensity of coughing for clearance of penetration and aspiration on video-fluoroscopy

PURPOSE

This preliminary, exploratory study evaluated the acoustic intensity of effective and ineffective clearance of penetrated and aspirated material from the laryngeal vestibule in patients with dysphagia.

METHOD

A lapel microphone was attached anterior to participants' tragus and recorded coughing in decibels during their videofluoroscopic swallowing studies (VFSS).

RESULT

Eighty-eight patients were recruited. Thirteen patients, with visible airway invasion and coughing were included in the final analysis. No coughs were effective at expelling aspirated material from the airway (n = 10). Both effective (4/7) and ineffective (3/7) coughing to penetration were recorded. The mean acoustic intensity of effective coughing to penetration was -44.0 dBFS (decibel level relative to full scale) [SD = 7.3, 95% CI = -51.14, -36.86], and ineffective coughing to penetration was only marginally lower at -42.9 dBFS [SD = 2.0, 95% CI = -45.21, -40.59].

CONCLUSION

No coughs were effective at expelling aspirated material from the airway. Some coughs effectively expelled penetrated material from the airway. However, the relationship between acoustic intensity and cough effectiveness is unclear due to the limited number of observations. Given that perceptual evaluation of coughing is widely used in dysphagia clinical practice to determine cough effectiveness, this is an important area for future research.

Correlation of Videofluoroscopic Swallowing Study Findings With Radionuclide Salivagram in Chronic Brain-Injured Patients

Objective

To investigate the correlation between videofluoroscopic swallowing study (VFSS) and radionuclide salivagram findings in chronic brain-injured patients with dysphagia.

Methods

Medical records of chronic brain-injured patients who underwent radionuclide salivagram and VFSS were retrospectively analyzed. Patients were divided into two groups according to salivagram findings. Differences in patient characteristics and clinical factors, including Mini-Mental State Examination (MMSE), Modified Barthel Index (MBI), Functional Ambulatory Category (FAC), feeding method, tracheostomy state, and VFSS findings between the two groups were investigated.

Results

A total of 124 patients were included in this study. There were no significant differences in MMSE, MBI, FAC, feeding method, and presence of tracheostomy between the two groups. However, the incidence of aspiration pneumonia history was significantly higher in the positive salivagram group. The Functional Dysphagia Scale (FDS) was significantly associated with positive salivagram findings, especially in the pharyngeal phase. A multivariate logistic regression analysis showed that laryngeal elevation and epiglottic closure was statistically significant FDS parameter in predicting salivary aspiration on a salivagram (odds ratio=1.100; 95% confidence interval, 1.017–1.190; p=0.018). The receiver operating characteristic (ROC) curve of FDS in the pharyngeal phase showed that an optimum sensitivity and specificity of 55.1% and 65.4%, respectively, when the cut-off value was 39.

Conclusion

In chronic brain-injured patients, inappropriate laryngeal elevation and epiglottic closure is predictive variable for salivary aspiration. Therefore, performing a radionuclide salivagram in patients with FDS of 39 or less in the pharyngeal phase for prevents aspiration pneumonia from salivary aspiration.

Recovery process of respiratory muscle strength in patients following stroke: A Pilot Study

OBJECTIVE

To determine the recovery process of respiratory muscle strength during 3 months following stroke, and to investigate the association of change in respiratory muscle strength and physical functions. Additionally, we compared respiratory muscle strength with those of healthy subjects.

METHOD

In this prospective, observational study, 19 stroke patients and 19 healthy subjects were enrolled. Maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), motricity index, trunk control test, 6-minute walk test (6MWT) and functional independence measure were assessed at 1, 2, and 3 months from stroke onset in stroke patients. MIP and MEP were assessed at arbitrary times in healthy subjects. Repeated one-way analysis of variance with Bonferroni post-hoc test was used to compare the change in respiratory muscle strength in each period in stroke patients. Pearson's correlation coefficient was computed for changes in respiratory muscle strength and physical functions. Student's t-test was used to compare respiratory muscle strength between stroke patients at 3 months from onset and healthy subjects.

RESULTS

MIP was significantly increased at 3 months compared to 1 month. MEP was significantly increased in 2 months and 3 months, compared to 1 month. MIP changes associated with 6MWT changes. Compared to healthy subjects, MIP and MEP at 3 months were significantly lower in stroke patients.

CONCLUSION

Respiratory muscle strength significantly increased during 3 months following stroke. However, the trend of recovery may be different. MIP changes may associated with walking endurance changes. During 3 months following stroke, respiratory muscle strength did not recover to healthy subjects.

Single and sequential voluntary cough in children with chronic spinal cord injury

We investigated the impact of spinal cord injury (SCI) on cough capacity in 10 children (Mean ± SD, age 8 ± 4 years) and compared it to 15 typically developing children (age 8 ± 3 years). Participants underwent spirometry, single and sequential cough assessment with surface-electromyography from respiratory muscles. Inspiratory phase duration, inspiratory phase peak flow, inspiratory phase rise time, compression phase duration, expiratory phase rise time, expiratory phase peak airflow (EPPF) and cough volume acceleration (CVA) parameters of single and sequential cough were measured. Root mean square (RMS) values of right pectoralis-major, intercostal, rectus-abdominus (RA), and oblique (OB) muscles were calculated and mean of three trials were compared. The significance criterion was set at P < 0.05. The SCI group produced significantly lower lung volumes, EPPF, CVA, and RMS values of RA and OB during expiratory phases of single and sequential coughs. The decrease in activation in expiratory muscles in the SCI group accounts for the impaired expiratory flow and may contribute to risk of respiratory complications.

Diagnostic Accuracy of a Bedside Screening Tool for Dysphagia (BSTD) in Acute Stroke Patients

BACKGROUND AND PURPOSE

an estimated 40-80% of acute ischemic stroke patients have dysphagia and about 14% develop stroke-associated pneumonia. However, it may be difficult to detect swallowing problems at admission. Moreover, there might not be an on-duty specialist skilled in the diagnosis of this condition. This study aimed at developing a user-friendly bedside examination to identify the risk of dysphagia in stroke patients at hospital admission.

METHODS

a diagnostic accuracy study was carried out to assess the concurrent validity of a simple Bedside Screening Tool for Dysphagia (BSTD) in acute stroke. All the consecutive stroke patients admitted between January and April 2018 were enrolled. Sensitivity, specificity, positive (PPV), negative predictive values (NPV) and the Cohen K concordance index scores, reported by nurses and speech-pathologists, were assessed.

RESULTS

a total of 67/120 patients (55.8%) were male; overall average age was 67.4 (range 45-91) and 80.8% of the whole population had a history of ischemic stroke. The nursing staff identified 33.3% of dysphagia cases at admission and the speech pathologists 30%. The Cohen K was 0.92 (optimal concordance when K was > 0.8), sensitivity was 100%, specificity 95.2%, PPV 90% and NPV 100%.

CONCLUSIONS

our BSTD had a 100% negative predictive value, indicating that this screening test is very useful in ruling out/confirming dysphagia in acute stroke patients.

Cut-off Values of the Respiratory Muscle Power and Peak Cough Flow in Post-Stroke Dysphagia

Background and objectives: This study aimed to determine the cut-off values of the following three respiratory pressure meters; the voluntary peak cough flow (PCF), maximal expiratory pressure (MEP) and maximal inspiratory pressure (MIP); associated with post-stroke dysphagia and assess which of these parameters show good diagnostic properties associated with post-stroke dysphagia. Materials and Methods: Retrospective analysis of a prospectively maintained database. Records of patients with first-ever diagnosed dysphagia attributable to cerebrovascular disease, who had performed spirometry measurements for the PCF, MIP and MEP. Results: From a total of 237 stroke patients, 163 patients were diagnosed with dysphagia. Those with dysphagia had significantly lower PCF values than those without dysphagia (116.3 ± 75.3 vs. 219.4 ± 91.8 L/min, p < 0.001). In addition, the former group also had lower MIP (30.5 ± 24.7 vs. 41.6 ± 25.7 cmH₂O, p = 0.0002) and MEP (41.0 ± 27.9 vs. 62.8 ± 32.3 cmH₂O, p < 0.001) values than the latter group. The receiver operating characteristic curve analysis showed that the PCF cut-off value of 151 L/min (area under the receiver operating characteristic curve [AUC] 0.81; sensitivity 72%; specificity 78.8%) was associated with post-stroke dysphagia. The optimum MEP and MIP cut-off were 38 cmH₂O (AUC 0.70, sensitivity 58%; specificity 77.7%) and 20 cmH₂O (AUC 0.65, sensitivity 49%; specificity 84%). PCF showed the highest AUC results. Results from the univariate analysis indicated that PCF values of ≤151 L/min increased risk of dysphagia by 9.51-fold (4.96–18.23). Multivariable analysis showed that after controlling of other clinical factor, the PCFs at this cut-off value still showed increased risk of by 4.19 (2.02–83.69) but this was not observed with the MIPs or MEPs. Conclusions: Our study has provided cut-off values that are associated with increased risk of dysphagia. Among the three parameters, PCF showed increased association with post-stroke dysphagia.

[Relationship between cough peak flow and onset of pneumonia in residents of geriatric health services facilities]

AIM

Sputum expectoration is associated with cough strength, which can be evaluated by cough peak flow (CPF). Since sputum expectoration can be difficult for patients with reduced CPF, they are more likely to have risk factors for pneumonia. We conducted a study to clarify factors contributing to CPF in residents of geriatric health services facilities and to assess the relationship between CPF and the onset of pneumonia.

METHODS

We included 41 male residents of geriatric health services facilities from September to the middle of October 2018. We recorded each subject's age, body mass index (BMI), Performance Status (PS), nursing care level, Functional Independence Measure (FIM), pulse rate, percutaneous arterial oxygen saturation (SpO₂), hand grip strength, Charlson comorbidity index, underlying diseases and rales upon auscultation. We also used Pearson's correlation analysis to analyze the relationship between CPF and the above factors. Subjects were assigned to 2 groups according to median CPF to determine the between-group relationships of these factors. Finally, subjects were followed up for 6 to 11 months after CPF measurement to confirm whether or not they developed pneumonia.

RESULTS

CPF was positively correlated with BMI (nutritional parameter), hand grip strength (index of systemic muscular strength), and SpO₂ The median CPF was 240 L/minute, and subjects were divided into 2 groups based on this valus: CPF ≤240 L/minute group (n=21) and CPF >240 L/minute group (n=20). Subjects in the CPF ≤240 L/minute group demonstrated lower BMI and hand grip strength but more pronounced rales upon auscultation. No statistically significant difference was observed between the 2 groups during the 6-month folloe-up. However, the 11-month follow-up demonstrated a higher incidence of pneumonia in the CPF ≤240 L/minute group.

CONCLUSION

The above findings suggest that subjects with reduced CPF are more likely to develop pneumonia. To increase CPF, muscle rehabilitation therapy and nutrition management should be provided to residents of geriatric health services facilities to prevent pneumonia.

Sex-specific vagal and spinal modulation of swallow and its coordination with breathing

Swallow-breathing coordination is influenced by changes in lung volume, which is modulated by feedback from both vagal and spinal sensory afferents. The purpose of this study was to manipulate feedback from these afferents, with and without a simultaneous mechanical challenge (chest compression), in order to assess the influence of each sensory pathway on swallow in rats. We hypothesized that manipulation of afferent feedback would shift the occurrence of swallow toward the inspiratory phase of breathing. Afferent feedback was perturbed by lidocaine nebulization, extra-thoracic vagotomy, or lidocaine administration to the pleural space in sodium pentobarbital anesthetized rats (N = 43). These different afferent perturbations were performed both in control conditions (no chest compression), and with chest compression. Manipulating pulmonary stretch receptor-mediated volume feedback in male animals decreased swallow occurrence. Female rats appear to rely more on spinal afferent feedback, as swallow occurrence shifted to late expiration with chest compression and vagotomy or lidocaine injections. Results suggest that sex-specific mechanisms modulate swallow-breathing coordination, and that vagal feedback is inhibitory to swallow-related muscles, while spinal feedback from pleural afferents has excitatory effects. This study supports the theory that a balance of vagal and spinal afferent feedback is necessary to maintain an optimal swallow pattern and swallow-breathing coordination.

Comparison Between M-Mode Ultrasonography and Fluoroscopy for Diaphragm Excursion Measurement in Patients With Acquired Brain Injury

OBJECTIVES

Patients with acquired brain injury show decreased pulmonary function and diaphragm excursion (DE), which can affect functional outcomes. This study aimed to compare ultrasonography (US) and fluoroscopy for DE assessment and to determine how the relationship between pulmonary function test results and DE differs according to the paralytic condition.

METHODS

From September 2017 to April 2018, we prospectively enrolled patients with acquired brain injury. The patients underwent a pulmonary function test, including the functional vital capacity, forced expiratory volume at 1 second, forced expiratory volume at 1 second-to-functional vital capacity ratio, peak cough flow, and respiratory muscle strength such as the maximal inspiratory pressure and maximal expiratory pressure. Diaphragm excursion was measured with M-mode US and fluoroscopy on admission. A partial correlation analysis was used to assess the correlation between US and fluoroscopy for DE assessment.

RESULTS

During the study period, 50 patients with acquired brain injury were enrolled. After adjusting for age, sex, height, and weight, the correlation coefficients between US and fluoroscopy were 0.744 for the right side (P < .001) and 0.631 for the left side (P < .001). In a subgroup analysis for patients with hemiplegia, the correlation coefficients were 0.507 for the paretic side (P = .007) and 0.677 for the nonparetic side (P < .001). Diaphragm excursion in the nonparetic side was significantly correlated with the maximal inspiratory pressure, maximal expiratory pressure, and peak cough flow (P < .05).

CONCLUSIONS

M-mode US can be an alternative method for DE measurement in patients with impaired locomotion function after acquired brain injury. Preserved function of the nonparetic side might affect pulmonary function after brain injury, which suggests the importance of prestroke respiratory function.

The assessment of the peak of reflex cough in subjects with acquired brain injury and tracheostomy and healthy controls

INTRODUCTION

There is no standard procedure to evaluated the peak of reflex cough flow (PCF-reflex) in the literature, which is important assessment in subjects with acquired brain injury and tracheostomy cannula. The present study aims to investigate the PCF of the reflex cough in a broad sample of healthy controls and, furthermore, the presence and the strength of voluntary and reflex cough in subjects with ABI with tracheostomy cannula.

MATERIALS AND METHODS

We recruited 147 participants including the healthy subjects (n = 105) and acquired brain injury subjects (n = 43), who underwent respiratory assessment: the Tidal Volume, Forced Vital Capacity, PCF of voluntary cough (PCF-voluntary) and PCF-reflex (using a spirometer connected with a nebulizer by a bidirectional).

RESULTS

The PCF-reflex of controls and subjects was significant lower than the PCF-voluntary (P < 0.01). The PCF-voluntary was not assessed in 26 (60.5 %) subjects due to severe cognitive deficit. In subjects without cognitive deficits (n = 17; 39.5 %), it was significantly lower than in healthy controls (p < 0.01). In contrast, the PCF-reflex was completed in all subjects and it was not significantly different from healthy controls. Furthermore, the strength of the PCF-reflex decreased with increasing inhalation numbers of nebulised air.

CONCLUSION

Reflex cough behaviour differs largely from voluntary cough and the PCF results reflect this great discrepancy. PCF-reflex could be useful parameter for assessing the airway protection whereas PCF-voluntary for measuring airway clearance.

Evaluation of the Chinese version of the swallowing screen in stroke patients with dysphagia

Objective:

The purpose of this study was to validate a Chinese version of the modified Standardized Swallowing Assessment (SSA) instrument used by nurses in stroke patients with dysphagia and explore the feasibility of the simplified instrument.

Materials and Methods:

This study involved a cross-sectional design. Nurses independently applied the modified SSA to 127 patients with stroke before a complete dysphagia evaluation conducted by a speech–language pathologist. Factor analysis of eight dysphagia variables in the modified SSA was performed to evaluate construct validity. The accuracy of the screening instrument was assessed through receiver operating characteristic (ROC) analysis.

Results:

The comprehensive swallowing assessment revealed that 49.6% of the stroke patients had dysphagia. The modified SSA had an acceptable internal consistency coefficient. The inter-rater agreement between nurses using the modified SSA showed a Kappa coefficient of 0.509. All items had a communality loading of >0.5, and two factors accounted for 73.89% of the response variance. The area under the ROC curve was 0.79 (95% confidence interval: 0.71–0.87). The sensitivity and specificity derived for dysphagia detection were satisfactory according to the results obtained from the original 8-item and simplified 6-item scales (sensitivities = 82.50% and 81.00% and specificities = 59.40% and 64.10%, respectively; accuracy = 70.87% and 72.44%, respectively).

Conclusion:

This preliminary study suggests that the modified SSA is a potentially reliable and valid nurse-administered screening instrument for dysphagia detection in patients with stroke.

Swallowing with Noninvasive Positive-Pressure Ventilation (NPPV) in Individuals with Muscular Dystrophy: A Qualitative Analysis

The purpose of the study is to describe experiences of swallowing with two forms of noninvasive positive-pressure ventilation (NPPV): mouthpiece NPPV (M-NPPV) and nasal bilevel positive airway pressure (BPAP) in people with muscular dystrophy. Ten men (ages 22-42 years; M = 29.3; SD = 7.1) with muscular dystrophy (9 with Duchenne's; 1 with Becker's) completed the Eating Assessment Tool (EAT-10; Ann Otol Rhinol Laryngol 117(12):919-924 [33]) and took part in semi-structured interviews. The interviews were audio recorded, transcribed, and verified. Phenomenological qualitative research methods were used to code (Dedoose.com) and develop themes. All participants affirmed dysphagia symptoms via responses on the EAT-10 (M = 11.3; SD = 6.38; Range = 3-22) and reported eating and drinking with M-NPPV and, to a lesser extent, nasal BPAP. Analysis of interview data revealed three primary themes: (1) M-NPPV improves the eating/drinking experience: Most indicated that using M-NPPV reduced swallowing-related dyspnea. (2) NPPV affects breathing-swallowing coordination: Participants described challenges and compensations in coordinating swallowing with ventilator-delivered inspirations, and that the time needed to chew solid foods between ventilator breaths may lead to dyspnea and fatigue. (3) M-NPPV aids cough effectiveness: Participants described improved cough strength following large M-NPPV delivered inspirations (with or without breath stacking). Although breathing-swallowing coordination is challenging with NPPV, participants reported that eating and drinking is more comfortable than when not using it. Overall, eating and drinking with NPPV delivered via a mouthpiece is preferred and is likely safer for swallowing than with nasal BPAP. M-NPPV (but not nasal BPAP) is reported to improve cough effectiveness, an important pulmonary defense in this population.

Different clinical predictors of aspiration pneumonia in dysphagic stroke patients related to stroke lesion: A STROBE-complaint retrospective study

Although stroke is one of the most common causes of dysphagia, no studies have investigated the radionuclide salivagram as a predictor of aspiration pneumonia in patients with stroke. In addition, few researches on the risk factors of aspiration pneumonia in patients with subacute and chronic stroke undergoing rehabilitation in the rehabilitation unit have been rarely conducted. In this study, therefore, we investigated whether a radionuclide salivagram could predict aspiration pneumonia, and tried to find other clinical factors that may be helpful in predicting aspiration pneumonia in stroke patients undergoing rehabilitation in the rehabilitation department.From March 2013 and January 2018, a retrospective review of the medical records of 1182 subacute and chronic stroke patients who were admitted to rehabilitation department (South Korea) was carried out. We included 117 stroke patients with swallowing difficulties who were admitted to our rehabilitation department and satisfied our criteria retrospectively. Stroke lesion, the degree of paralysis, sex, age, onset duration, feeding methods, the Mini-Mental State Examination (MMSE), the Global Deterioration Scale (GDS), the presence of aspiration in VFSS or salivagram, the penetration-aspiration scale (PAS), and the total score of the Modified Barthel Index (MBI) were investigated by reviewing medical records.To evaluate the predictor of aspiration pneumonia for patients with stroke, multivariate logistic regression analysis with forward stepwise was performed. In the results of this study, only MMSE was significant as a clinical predictor, but not aspiration in VFSS or salivagram in multivariate analysis of supratentorial stroke patients (OR, 0.895) (95% CI, 0.830-964). In multivariate analysis of infratentorial stroke patients, combined results of salivagram and VFSS (aspiration in a salivagram or VFSS) (OR, 0.956) (95% CI, 0.919-995), and total MBI scores were significant as clinical predictors (OR, 24.882) (95% CI, 1.298-477.143).In conclusion, MMSE can be a clinical predictor of the occurrence of aspiration pneumonia in patients with supratentorial stroke. In contrast, total MBI score and combined results of a salivagram and VFSS can be clinical predictors of the occurrence of aspiration pneumonia in patients with infratentorial stroke.

Strategies for the Integration of Cough and Swallow to Maintain Airway Protection in Humans

PURPOSE

Airway protective behaviors, like cough and swallow, deteriorate in many populations suffering from neurologic disorders. While coordination of these behaviors has been investigated in an animal model, it has not been tested in humans.

METHODS

We used a novel protocol, adapted from previous work in the cat, to assess cough and swallow independently and their coordination strategies in seven healthy males (26 ± 6 years). Surface electromyograms of the submental complex and external oblique complex, spirometry, and thoracic and abdominal wall kinematics, were used to evaluate the timing of swallow, cough, and breathing as well as lung volume (LV) during these behaviors.

RESULTS

Unlike the cat, there was significant variability in the cough-swallow phase preference; however, there was a targeted LV range in which swallow occurred.

CONCLUSION

These results give insight into the differences between the cat and human models in airway protective strategies related to the coordination of cough and swallow behaviors, allowing for better understanding of dystussia and dysphagia.

Breathing matters

Breathing is a well-described, vital and surprisingly complex behaviour, with behavioural and physiological outputs that are easy to directly measure. Key neural elements for generating breathing pattern are distinct, compact and form a network amenable to detailed interrogation, promising the imminent discovery of molecular, cellular, synaptic and network mechanisms that give rise to the behaviour. Coupled oscillatory microcircuits make up the rhythmic core of the breathing network. Primary among these is the preBötzinger Complex (preBötC), which is composed of excitatory rhythmogenic interneurons and excitatory and inhibitory pattern-forming interneurons that together produce the essential periodic drive for inspiration. The preBötC coordinates all phases of the breathing cycle, coordinates breathing with orofacial behaviours and strongly influences, and is influenced by, emotion and cognition. Here, we review progress towards cracking the inner workings of this vital core.

Implementing Cough Reflex Testing in a Clinical Pathway for Acute Stroke: A Pragmatic Randomised Controlled Trial

Silent aspiration is common after stroke and can lead to subsequent pneumonia. While standard bedside dysphagia assessments are ineffective at predicting silent aspiration, cough reflex testing (CRT) has shown promise for identifying patients at risk of silent aspiration. We investigated the impact of CRT on patient and service outcomes when embedded into a clinical pathway. 488 acute stoke patients were randomly allocated to receive either CRT or standard care (i.e. bedside assessment). Primary outcomes included confirmed pneumonia within 3 months post stroke and length of acute inpatient stay. Secondary outcomes related to the feasibility of implementing a CRT pathway and clinician and patient satisfaction. There was a non-significant reduction in pneumonia rates by 2.2% points in the CRT group (OR 0.32, 95% CI 0.06-1.62). There was a non-significant difference of 0.7 days (95% CI - 0.29 to 1.71 days) in length of stay between the standard care group and the CRT group. The CRT took on average 3 min longer to complete (p < 0.01) and resulted in a significant 6.7% increase in videofluoroscopic referrals (p = 0.02); however, these results are clinically insignificant. High patient and clinician satisfaction with CRT was found, with clinicians reporting additional knowledge and confidence in decision making for dysphagia management. Post hoc subgroup analyses according to stroke types were conducted and revealed no significant differences in pneumonia rates after adjustment for multiple comparisons. In conclusion, it was possible to implement a CRT pathway with minimal increases in clinician resources. While clinicians perceived CRT as beneficial in clinical decision making, the efficacy of CRT for reducing pneumonia rates in acute stroke remains to be established.Clinical Trial Registration-URL: http://www.anzctr.org.au . Unique identifier: ACTRN12616000724471.

Usefulness of Early Videofluoroscopic Swallowing Study in Acute Stroke Patients With Dysphagia

Objective

To demonstrate the usefulness of early videofluoroscopic swallowing study (VFSS) and to investigate change patterns in dietary methods in stroke patients with dysphagia.

Methods

The VFSS was performed within 7 days of stroke onset in neurologically stable patients. The patients were divided into three groups according to type of brain lesion: cortical lesion (CL), subcortical lesion (SCL), and brainstem/cerebellar lesion (BCL). Based on the VFSS results, this study investigated change patterns in feeding method and discrepancies in the aspiration risk predicted by the Water Swallowing Test (WST) and the VFSS. Complications, such as aspiration pneumonia, were also evaluated.

Results

A total of 163 patients met the inclusion criteria and the VFSS was performed within 7 days of stroke. Patients considered at risk for aspiration (Penetration-Aspiration Scale [PAS] scores of 6 to 8) were found in all three groups using the VFSS (47.5% of the CL group, 59.3% of the SCL group, and 47.9% of the BCL group). After early VFSS, 79.7% of the patients were assessed to require restricted feeding methods. A 19.0% discrepancy was found between the WST and VFSS results. At 3-week follow-up after the VFSS, aspiration pneumonia was observed in 12 patients (7.4%) with restricted feeding methods.

Conclusion

Early VFSS during the acute period can facilitate determination of the most appropriate feeding method, and support effective dysphagia management for stroke patients.

The double-sidedness of cough in the elderly

Cough is a physiological reflex to protect airways against aspiration, but also it is one of the most frequent problems that lead patients to seek medical care. Chronic cough is more prevalent in the elderly than younger subjects, and more challenging to manage due to frequent comorbidities and possible side effects from drug treatment. Meanwhile, cough reflex does not decrease with natural aging but is often impaired by pathologic conditions like stroke. The impairment in cough reflex may lead to fatal complication like aspiration pneumonia. In this paper, we reviewed epidemiology and clinical considerations for chronic cough in the elderly, and summarized aging-related changes in cough reflex and also possible ways to normalize cough reflex and prevent aspiration pneumonia.