An Exploration of Lung Volume Effects on Swallowing in Chronic Obstructive Pulmonary Disease

Purpose Chronic obstructive pulmonary disease (COPD) limits respiration, which may negatively impact airway safety during swallowing. It is unknown how differences in lung volume in COPD may alter swallowing physiology. This exploratory study aimed to determine how changes in lung volume impact swallow duration and coordination in persons with stable state COPD compared with older healthy volunteers (OHVs). Method Volunteers ≥ 45 years with COPD (VwCOPDs; n = 9) and OHVs ( n = 10) were prospectively recruited. Group and within-participant differences were examined when swallowing at different respiratory volumes: resting expiratory level (REL), tidal volume (TV), and total lung capacity (TLC). Participants swallowed self-administered 20-ml water boluses by medicine cup. Noncued (NC) water swallows were followed by randomly ordered block swallowing trials at three lung volumes. Estimated lung volume (ELV) and respiratory–swallow patterning were quantified using spirometry and respiratory inductive plethysmography. Manometry measured pharyngeal swallow duration from onset of base of tongue pressure increase to offset of negative pressure in the pharyngoesophageal segment. Results During NC swallows, the VwCOPDs swallowed at lower lung volumes than OHVs ( p = .011) and VwCOPDs tended to inspire after swallows more often than OHVs. Pharyngeal swallow duration did not differ between groups; however, swallow duration significantly decreased as the ELV increased in VwCOPDs ( p = .003). During ELV manipulation, the COPD group inspired after swallowing more frequently at REL than at TLC ( p = .001) and at TV ( p = .002). In conclusion, increasing respiratory lung volume in COPD should improve safety by reducing the frequency of inspiration after a swallow.

Validation and Inter-rater Reliability of the Modified Videofluoroscopic Dysphagia Scale (mVDS) in Dysphagic Patients with Multiple Etiologies

Background: the Videofluoroscopic Dysphagia Scale (VDS) is used to interpret and predict the long-term prognosis of patients with dysphagia. However, the inter-rater agreement of the VDS was shown to be lower in a previous study. To overcome the mentioned limitation of the VDS, a modified version (mVDS) was created and applied clinically. We aimed to validate its usefulness in determining the appropriate feeding method and predicting the prognosis of dysphagia. Methods: the videofluroscopic swallowing study (VFSS) data of 50 patients with dysphagia were collected retrospectively. The VFSS data were evaluated using the mVDS, and the inter-rater reliability was calculated. We also evaluated the association between the mVDS and type of feeding method selected, and between the mVDS and presence of aspiration pneumonia in patients with dysphagia. Results: among the different parameters of mVDS, “aspiration” showed the highest reliability (k = 0.767), followed by “mastication” and “lip closure” (k = 0.648 and k = 0.634, respectively). Conversely, “triggering pharyngeal swallow” and “pyriformis residue” demonstrated the lowest reliabilities (k = 0.312 and k = 0.324, respectively). The intraclass correlation coefficient (ICC), which is used as a measure of the reliability of the total mVDS score, was 0.876. In all patients with dysphagia, the mVDS score correlated significantly with the type of feeding method selected (p < 0.05), and the presence of aspiration pneumonia (p < 0.05). Conclusion: the ICC of the total mVDS score was 0.876. Therefore, the mVDS could be a useful tool for quantifying the severity of dysphagia. It could be helpful in the analysis of the VFSS findings among patients with dysphagia in clinical settings and research.

The role of the area postrema in belching

Introduction: The primary reflex involved with belching is associated with the activation of neurons in the area postrema (AP), therefore, we investigated the role of the AP in the activation of belching. Methods: The effects of mechanical lesions of the dorsal brainstem on activation of belching, esophago-UES contractile reflex (EUCR), and the pharyngeal swallow (PS) were determined in 13 decerebrate cats. Discussion: Bilateral lesions of the dorsal brain stem which included the rostral AP significantly (P< 0.05, N = 7) blocked belching, but not the other reflexes. Bilateral lesions of the rostral AP only blocked belching (N=2). When belching was blocked, the same belch stimulus activated EUCR (in 6 out of 7 animals). Unilateral lesions of the AP (N = 3) did not block belching. Conclusions: The rostral AP is essential for activation of belching. We hypothesize that the AP serves an inhibitory function to prevent reflexes that promote orthograde transport, e.g. PS, and reflexes that prevent supra-esophageal reflux, e.g. EUCR, thereby, facilitating retrograde transport. Keywords: Belching; brain stem; area postrema.

Rapid activation of esophageal mechanoreceptors alters the pharyngeal phase of swallow: Evidence for inspiratory activity during swallow

Swallow is a complex behavior that consists of three coordinated phases: oral, pharyngeal, and esophageal. Esophageal distension (EDist) has been shown to elicit pharyngeal swallow, but the physiologic characteristics of EDist-induced pharyngeal swallow have not been specifically described. We examined the effect of rapid EDist on oropharyngeal swallow, with and without an oral water stimulus, in spontaneously breathing, sodium pentobarbital anesthetized cats (n = 5). Electromyograms (EMGs) of activity of 8 muscles were used to evaluate swallow: mylohyoid (MyHy), geniohyoid (GeHy), thyrohyoid (ThHy), thyropharyngeus (ThPh), thyroarytenoid (ThAr), cricopharyngeus (upper esophageal sphincter: UES), parasternal (PS), and costal diaphragm (Dia). Swallow was defined as quiescence of the UES with overlapping upper airway activity, and it was analyzed across three stimulus conditions: 1) oropharyngeal water infusion only, 2) rapid esophageal distension (EDist) only, and 3) combined stimuli. Results show a significant effect of stimulus condition on swallow EMG amplitude of the mylohyoid, geniohyoid, thyroarytenoid, diaphragm, and UES muscles. Collectively, we found that, compared to rapid cervical esophageal distension alone, the stimulus condition of rapid distension combined with water infusion is correlated with increased laryngeal adductor and diaphragm swallow-related EMG activity (schluckatmung), and post-swallow UES recruitment. We hypothesize that these effects of upper esophageal distension activate the brainstem swallow network, and function to protect the airway through initiation and/or modulation of a pharyngeal swallow response.

Sucking versus swallowing coordination, integration, and performance in preterm and term infants

Physiological maturation of infant feeding is clinically and developmentally significant, but seldom examined as an integrated function. Using longitudinal high-speed videofluoroscopic data, we found that properties of sucking, such as the length of the suck, are more sensitive to swallow physiology than those associated with the pharyngeal swallow itself, such as hyoid excursion. Prematurity impacted the function and maturation of the feeding system, resulting in a physiology that fundamentally differs from term infants by weaning.

Effects of texture properties of semi-solid food on the sensory test for pharyngeal swallowing effort in the older adults

Background Increasing viscosity can reduce the risk of aspiration into the airway, but excessively thickened food may require more force and effort. We assumed that semi-solid foods with similar viscosities will behave differently in the oropharynx and there might exist the possibility that properties other than viscosity may have clinical relevance. This study aimed to find out the texture of semi-solid foods that affects the effort of pharyngeal swallow in the older adults. Methods Nine kinds of semi-solid foods not requiring mastication were selected for texture profile analysis (TPA), and included whipped cream, mayonnaise, soft tofu, mango pudding, boiled mashed pumpkin, boiled mashed potatoes, boiled mashed sweet potatoes, red bean paste, and peanut butter. Hardness, adhesiveness and cohesiveness of each food were measured three times by using the rheometer. A blinded sensory test using a 9-point hedonic scale was also conducted in eighteen older adults people to investigate how much effort was required to swallow food, and how much of the food remained in the pharynx after swallowing. The correlation between texture and sensory outcome was statistically analyzed. Results Foods that belonged to the same viscosity category showed different texture values, and the participants also rated different scores respectively. Only adhesiveness among three properties was significantly correlated with the sensory test. (r = 0.882, p = 0.002 for difficult to swallow, r = 0.879, p = 0.002 for sense of residue). Conclusions Adhesiveness was the most important property of the semi-solid foods, requiring most efforts in pharyngeal swallow in the older adults. If we select and provide food having low adhesiveness value in the same viscosity category, there might be the possibility to make it easier to swallow in older adults.

Effects of texture properties of semi-solid food on the sensory test for pharyngeal swallowing effort in the older adults

Background: Increasing viscosity can reduce the risk of aspiration into the airway, but excessively thickened food may require more force and effort. We assumed that semi-solid foods with similar viscosities will behave differently in the oropharynx and there might exist the possibility that properties other than viscosity may have clinical relevance. This study aimed to find out the texture of semi-solid foods that affects the effort of pharyngeal swallow in the older adults. Methods: Nine kinds of semi-solid foods not requiring mastication were selected for texture profile analysis (TPA), and included whipped cream, mayonnaise, soft tofu, mango pudding, boiled mashed pumpkin, boiled mashed potatoes, boiled mashed sweet potatoes, red bean paste, and peanut butter. Hardness, adhesiveness and cohesiveness of each food were measured three times by using the rheometer. A blinded sensory test using a 9-point hedonic scale was also conducted in eighteen older adults people to investigate how much effort was required to swallow food, and how much of the food remained in the pharynx after swallowing. The correlation between texture and sensory outcome was statistically analyzed.Results: Foods that belonged to the same viscosity category showed different texture values, and the participants also rated different scores respectively. Only adhesiveness among three properties was significantly correlated with the sensory test. (r= 0.882, p=0.002 for difficult to swallow, r=0.879, p=0.002 for sense of residue).Conclusions: Adhesiveness was the most important property of the semi-solid foods, requiring most efforts in pharyngeal swallow in the older adults. If we select and provide food having low adhesiveness value in the same viscosity category, there might be the possibility to make it easier to swallow in older adults.

Factors Influencing Initiation of Pharyngeal Swallow in Healthy Adults

Purpose The purpose of this study was to investigate factors influencing the initiation of pharyngeal swallow (IPS) in healthy, nondysphagic adults. Method A total of 195 healthy participants ranging in age from 21 to 89 years participated in a modified barium swallow study. IPS was quantified using the Modified Barium Swallow Impairment Profile standardized scoring system across nine swallowing tasks observed in the lateral viewing plane for each participant. Results Large variability for bolus head location at time of hyoid burst (IPS) was observed within this healthy cohort, ranging from the ramus of the mandible to the pyriform sinuses. Significant effects of bolus volume, viscosity, sex, and race were also observed. Conclusion Study findings indicate that IPS is variable in healthy adults and influenced by volume, viscosity, sex, and race. Thus, variability in IPS may be considered typical in otherwise nondysphagic adults. The clinical significance of high Modified Barium Swallow Impairment Profile IPS scores in dysphagic patients, therefore, must be considered within the context of other swallowing impairments. Supplemental Material https://doi.org/10.23641/asha.12735935

Effects of texture properties of semi-solid food on the sensory test for pharyngeal swallowing effort in the elderly

Background: Increasing viscosity can reduce the risk of aspiration into the airway, but conversely, very thick solid food may require greater strength and effort. We assumed that semi-solid foods with similar viscosities will behave differently in the oropharynx and there might exist the possibility that properties other than viscosity may have clinical relevance. This study aimed to find out the texture of semi-solid foods that affects the effort of pharyngeal swallow in the elderly. Methods: Nine kinds of semi-solid foods not requiring mastication were selected for texture profile analysis (TPA), and included whipped cream, mayonnaise, soft tofu, mango pudding, boiled mashed pumpkin, boiled mashed potatoes, boiled mashed sweet potatoes, red bean paste, and peanut butter. Hardness, adhesiveness and cohesiveness of each food were measured three times by using the rheometer. A blinded sensory test using a 9-point hedonic scale was also conducted in eighteen elderly people to investigate how much effort was required to swallow food, and how much of the food remained in the pharynx after swallowing. The correlation between texture and sensory outcome was statistically analyzed.Results: Foods that belonged to the same viscosity category showed different texture values, and the participants also rated different scores respectively. Only adhesiveness among three properties was significantly correlated with the sensory test. (r= 0.882, p=0.002 for difficult to swallow, r=0.879, p=0.002 for sense of residue).Conclusions: Adhesiveness was the most important property of the semi-solid foods, requiring most efforts in pharyngeal swallow in the elderly. If we select and provide food having low adhesiveness value in the same viscosity category, there might be the possibility to make it easier to swallow in older adults.