Effects of age and viscosity on food transport and breathing-swallowing coordination during eating of two-phase food in nursing home residents

Bioenergetic Evaluation of Muscle Fatigue in Murine Tongue

Muscle fatigue is the diminution of force required for a particular action over time. Fatigue may be particularly pronounced in aging muscles, including those used for swallowing actions. Because risk for swallowing impairment (dysphagia) increases with aging, the contribution of muscle fatigue to age-related dysphagia is an emerging area of interest. The use of animal models, such as mice and rats (murine models) allows experimental paradigms for studying the relationship between muscle fatigue and swallowing function with a high degree of biological precision that is not possible in human studies. The goal of this article is to review basic experimental approaches to the study of murine tongue muscle fatigue related to dysphagia. Traditionally, murine muscle fatigue has been studied in limb muscles through direct muscle stimulation and behavioral exercise paradigms. As such, physiological and bioenergetic markers of muscle fatigue that have been validated in limb muscles may be applicable in studies of cranial muscle fatigue with appropriate modifications to account for differences in muscle architecture, innervation ratio, and skeletal support. Murine exercise paradigms may be used to elicit acute fatigue in tongue muscles, thereby enabling study of putative muscular adaptations. Using these approaches, hypotheses can be developed and tested in mice and rats to allow for future focused studies in human subjects geared toward developing and optimizing treatments for age-related dysphagia.

Effects of Food and Liquid Properties on Swallowing Physiology and Function in Adults

Foods and liquids have properties that are often modified as part of clinical dysphagia management to promote safe and efficient swallowing. However, recent studies have questioned whether this practice is supported by the evidence. To address this, a scoping review was conducted to answer the question: "Can properties of food and liquids modify swallowing physiology and function in adults?" Online search in six databases yielded a set of 4235 non-duplicate articles. Using COVIDENCE software, two independent reviewers screened the articles by title and abstract, and 229 full-text articles were selected for full-text review. One-hundred eleven studies met the inclusion criteria for qualitative synthesis and assessment of risk of bias. Three randomized controlled trials and 108 non-randomized studies were analyzed. Large amounts of variability in instrumental assessment, properties of food and liquids, and swallowing measures were found across studies. Sour, sweet, and salty taste, odor, carbonation, capsaicin, viscosity, hardness, adhesiveness, and cohesiveness were reported to modify the oral and pharyngeal phase of swallowing in both healthy participants and patients with dysphagia. Main swallow measures modified by properties of food and liquids were penetration/aspiration, oral transit time, lingual pressures, submental muscle contraction, oral and pharyngeal residue, hyoid and laryngeal movement, pharyngeal and upper esophageal sphincter pressures, and total swallow duration. The evidence pooled in this review supports the clinical practice of food texture and liquid consistency modification in the management of dysphagia with the caveat that all clinical endeavors must be undertaken with a clear rationale and patient-specific evidence that modifying food or liquid benefits swallow safety and efficiency while maintaining quality of life.

Interventions to prevent aspiration in older adults with dysphagia living in nursing homes: a scoping review

Background

Dysphagia is highly prevalent condition in older adults living in nursing homes. There is also evidence indicating that aspiration is one of the major health risks for these older adults, which is more likely to result in respiratory infections, aspiration pneumonia and sudden bolus death. Evidence syntheses have demonstrated the effectiveness of interventions for prevention of aspiration among hospitalized older people. The aim of this scoping review is to describe the current spread of interventions to prevent or reduce aspiration in older adults with dysphagia with a specific focus on those who reside in nursing homes.

Methods

The Joanna Briggs Institute methods and PRISMA-ScR guidelines were used to inform this review. MEDLINE, CINAHL, EMBASE, Cochrane Library, Joanna Briggs Institute EBP Database and Web of Science were searched for related articles from 2010 to 2020 as well as Chinese databases (CNKI, WANFANG DATA and VIP) and databases for unpublished material. A three-step search strategy was utilized, including the use of citation software to manage search results and de-duplication, abstract review and full-text review by two reviewers. Details of included studies were then extracted using a prepared data extraction tool. The resulting map was displayed in tabular form along with a narrative summary.

Results

Although 637 articles were located, 19 papers were included in the final analysis. Interventions to prevent aspiration in older adults with dysphagia living in nursing homes included: more bedside evaluation, modification of dietary, creating an appropriate environment for swallowing, providing appropriate feeding assistance, appropriate posture or maneuver for swallowing, appropriate rehabilitation program, medication treatment, and stimulation treatment.

Conclusion

Nursing homes, particularly those in developing countries, require more support for staff training and necessary equipment. Professional interventions provided by speech and language therapists are still limited in the setting of nursing homes. Modification of dietary was the most frequently used intervention to prevent or reduce aspiration. Multi-disciplinary interventions had the best results for aspiration management, but for many nursing homes, access to such teams is limited. Nursing home residents respond well to person-centered interventions that have a comprehensive consideration of their degree of aspiration risk, health condition, individual feelings and cognitive state.

Effectiveness of fibreoptic endoscopic evaluation of swallowing and dietary intervention during home-visit dental care in older individuals

BACKGROUND

Currently, patients with dysphagia are receiving dietary management that deviates from their original swallowing function.

OBJECTIVE

To evaluate the clinical significance of fibreoptic endoscopic evaluation of swallowing (FEES) and dietary intervention (DI) by multi-professional collaboration during visit care for determining the actual oral intake status in patients with dysphagia.

METHODS

Five hundred and eighteen patients with dysphagia underwent FEES, focusing on the penetration-aspiration scale, and DI. Oral intake status was categorised using the functional oral intake scale (FOIS). FOIS scores at the first visit, after FEES, and at the reassessment were compared.

RESULTS

At the first visit, 34.7% of the patients had an FOIS score of level 1 (no oral intake) and 65.3% had a score of level 2 or higher (capable of oral intake). Following FEES, 7.1% of patients had an FOIS score of level 1, and 44.4% had a score of level 2 with resumption of oral intake. At the reassessment, 489 patients (94.4%) were capable of oral ingestion (FOIS level 2 or higher). There were significant differences between the distributions of FOIS scores at the first visit and following FEES (P < .01) and between those at the first visit and at the reassessment (P < .01). Regarding tube feeding, 17 (5.9%) of 289 patients, who had received tube feeding at the first visit, were completely capable of oral intake following FEES and at the reassessment.

CONCLUSION

Appropriate evaluation of swallowing function using FEES and DI helps to understand the definite swallowing function in patients with dysphagia.

Mixed Consistencies in Dysphagic Patients: A Myth to Dispel

Only limited and inconsistent information about the effect of mixed consistencies on swallowing are available. The aim of this study was to evaluate the location of the head of the bolus at the swallow onset, the risk of penetration/aspiration, and the severity of post-swallow pharyngeal residue in patients with dysphagia when consuming mixed consistencies. 20 dysphagic patients underwent a Fiberoptic Endoscopic Evaluation of Swallowing (FEES) testing five different textures: liquid, semisolid, solid, biscuits-with-milk and vegetable-soup. The location of the head of the bolus at the onset of swallowing was rated using a five-points scale ranging from zero (the bolus is behind the tongue) to four (the bolus falls into the laryngeal vestibule), the severity of penetration/aspiration was rated using the Penetration Aspiration Scale (PAS), the amount of pharyngeal residue after the swallow was rated using the Yale Pharyngeal Residue Severity Rating Scale (YPRSRS) in the vallecula and pyriform sinus. When consuming biscuits-with-milk and liquid the swallow onset occurred more often when the boluses were located in the laryngeal vestibule. Penetration was more frequent with biscuits-with-milk, while aspiration was more frequent with Liquid, followed by biscuits-with-milk and vegetable-soup, Semisolid and Solid. In particular, no differences in penetration and aspiration between liquids and biscuits-with-milk were found as well as among vegetable-soup, semisolid and solid. No significant differences in the amount of food residue after swallowing were demonstrated. The risk of penetration-aspiration for biscuits-with-milk and liquid is similar, while the risk of penetration-aspiration is lower for vegetable-soup than for liquid.

Prevalence, Pathophysiology, Diagnostic Modalities, and Treatment Options for Dysphagia in Critically Ill Patients

Postextubation dysphagia may impose a substantial burden on intensive care unit patients and healthcare systems. Approximately 517,000 patients survive mechanical ventilation during critical care annually. Reports of postextubation dysphagia prevalence are highly variable ranging between 3% and 93%. Of great concern is aspiration leading to the development of aspiration pneumonia when patients resume oral feeding. Screening for aspiration with a water swallow test has been reported to be positive for 12% of patients in the intensive care unit after extubation. This review aims to increase awareness of postextubation dysphagia and provide an updated overview of the current knowledge regarding prevalence, pathophysiology, diagnostic modalities, and treatment options.

A Systematic Review of the Influence of Bolus Characteristics on Respiratory Measures in Healthy Swallowing

There have been a number of studies on the effect of bolus volume, consistency, texture, temperature and taste on the oropharyngeal swallowing physiology. However, its influence on the respiratory function associated with swallow is not well understood. This study aimed at systematically analysing and documenting the prevailing research literature on respiratory functions before, during, and after healthy swallows of boluses with varied characteristics. The PRISMA guidelines were followed for retrieval of relevant research. From among the 48,329 reports screened for inclusion criteria, 25 articles were included for data extraction. Each of these reports was evaluated for its design, methodology and reporting quality and also the level of evidence provided by them. The results revealed that the scientific evidence in this regard was restricted to level II. Majority of the studies included considered bolus volume as the variable than bolus consistency, taste or temperature. Expiratory phase was preferred surrounding the apnea irrespective of volume, consistency or taste but changed with temperature variations across age groups. The reports are equivocal on the duration of respiratory apnea, and length of respiratory cycles before and after the apnea. The temporal coordination of pharyngeal swallow events was found to be independent of bolus volume. This review concluded that bolus characteristics have differential effects on the respiratory functions during swallow beyond a 'central sensory threshold' level. Objective standardization of bolus characteristics may be the immediate requirement for generalization of future research findings in this direction.

Respiratory-Swallow Pattern Following Total Laryngectomy

The goal of this study was to further characterize respiratory patterns in total laryngectomees with attention to respiratory-swallow pattern as it relates to presence/absence of tracheoesophageal puncture (TEP) and bolus consistency. It was hypothesized that participants with TEP would exhibit respiratory-swallow patterns that were significantly different than those without TEP and that bolus consistency (thin or solid) would modulate respiratory-swallow pattern. Data were collected from 12 adults (8 male), aged 46-67 years (mean 57) status post total laryngectomy (1-30 years; average 6 years). Those actively receiving chemoradiation, with history of esophageal cancer, with neurologic disease, with history of lung cancer, with known or suspected recurrence of head and neck cancer (HNC), or with severe cognitive deficits were excluded. Laryngectomy participants were asked to swallow three sips of water and three bites of graham cracker. Submental surface EMG activity was used to detect swallows and a custom stoma mask in line with a pneumotachograph measured airflow during the swallows. Non-parametric Mann-Whitney test for differences was used to detect significance for our dependent variables, TEP or bolus consistency and independent variables, respiratory-swallow pattern. Laryngectomee's showed preference for swallow during inspiration which is inconsistent with the expiratory pattern preference found in healthy adults with intact larynges by McFarland et al. (Respir Physiol Neurobiol 234:89-96, 2016) but consistent with the pattern preference for inspiration (or non-dominant respiratory-swallow phase pattern) found in the HNC population at-large by Brodsky et al. (J Appl Physiol 112(10):1698-1705, 2012). No significant difference was found in swallow pattern with regards to presence/absence of TEP or bolus consistency.

Optimizing Texture Modified Foods for Oro-pharyngeal Dysphagia: A Difficult but Possible Target?

Dysphagia is a swallowing disorder characterized by the difficulty in transferring solid foods and/or liquids from the oral cavity to the stomach, imparing autonomous, and safe oral feeding. The main problems deriving from dysphagia are tracheo-bronchial aspiration, aspiration pneumonia, malnutrition and dehydration. In order to overcome dysphagia-induced problems, over the years water and food thickening has been used, focusing specifically on viscosity increase, but limited results have been obtained. Elastic components and their effects on the cohesiveness on the bolus should be taken into account in the first place. We provide an analysis of dysphagia and suggest possible corrections to the protocols which are being used at present, taking into account rheological properties of food and the effect of saliva on the bolus. We reckon that considering such aspects in the dysphagia management market and healthcare catering would result in significant clinical risk reduction.