Spontaneous Swallowing Research Articles

Evidence for peripheral and central actions of codeine to dysregulate swallowing in the anesthetized cat

Systemic administration of opioids has been associated with aspiration and swallow dysfunction in humans. We speculated that systemic administration of codeine would induce dysfunctional swallowing and that this effect would have a peripheral component. Experiments were conducted in spontaneously breathing, anesthetized cats. The animals were tracheotomized and electromyogram (EMG) electrodes were placed in upper airway and chest wall respiratory muscles for recording swallow related motor activity. The animals were allocated into three groups: vagal intact (VI), cervical vagotomy (CVx), and supra-nodose ganglion vagotomy (SNGx). A dose response to intravenous codeine was performed in each animal. Swallowing was elicited by injection of 3 mL of water into the oropharynx. The number of swallows after vehicle was significantly higher in the VI group than in SNGx. Codeine had no significant effect on the number of swallows induced by water in any of the groups. However, the magnitudes of water swallow-related EMGs of the thyropharyngeus muscle were significantly increased in the VI and CVx groups by 2–4 fold in a dose-related manner. In the CVx group, the geniohyoid muscle EMG during water swallows was significantly increased. There was a significant dose-related increase in spontaneous swallowing in each group from codeine. The spontaneous swallow number at the 10 mg/kg dose of codeine was significantly larger in the CVx group than that in the SNGx group. During water-evoked swallows, intravenous codeine increased upper airway motor drive in a dose-related manner, consistent with dysregulation. The data support the existence of both central and peripheral actions of codeine on spontaneous swallowing. At the highest dose of codeine, the reduced spontaneous swallow number in the SNGx group relative to CVx is consistent with a peripheral excitatory action of codeine either on pharyngeal/laryngeal receptors or in the nodose ganglion itself. The higher number of swallows in the CVx group than the VI group supports disinhibition of this behavior by elimination of inhibitory vagal sensory afferents.

Apnea behavior in early- and late-stage mouse models of Parkinson's disease: Cineradiographic analysis of spontaneous breathing, acute stress, and swallowing

This study aimed to evaluate the timing and frequency of spontaneous apneas during breathing and swallowing by using cineradiography on mouse models of early/initial or late/advanced Parkinson’s disease (PD). C57BL/6 J mice received either 6-OHDA or vehicle injections into their right striatum, followed by respiratory movement recordings during spontaneous breathing and swallowing, and a stress challenge, two weeks later. Experimental group animals showed a significantly lower respiratory rate (158.66 ± 32.88 breaths/minute in late PD, 173.16 ± 25.19 in early PD versus 185.27 ± 25.36 in controls; p<0.001) and a significantly higher frequency of apneas (median 1 apnea/minute in both groups versus 0 in controls; p<0.001). Other changes included reduced food intake and the absence of swallow apneas in experimental mice. 6-OHDA-induced nigrostriatal degeneration in mice disrupted respiratory control, swallowing, stress responsiveness, and feeding behaviors, potentially hindering airway protection and elevating the risk of aspiration.

Difference in the Electromyographic Behavior of the Masticatory and Swallowing Muscles During Cued Versus Spontaneous Swallowing

The risk of dysphagia and/or aspiration is determined using screening tests, such as the repeated saliva swallowing test and modified water swallowing test, which evaluate cued swallowing. However, humans masticate and swallow foods with various consistencies, forms, and amounts, without conscious awareness. Therefore, this study aimed to examine the difference in the behavior of masticatory and swallowing muscles during spontaneous versus cued swallowing through a series of mastication and swallowing processes by evaluating surface electromyogram (sEMG) signals. The effect of the consistency and amount of food on the behavior of these muscles was also investigated. The sEMG recordings of the masseter muscles and anterior belly of the digastric muscle for 12 subjects, and genioglossus muscle for 5 subjects were obtained. The genioglossus activity was recorded using custom-made ball electrodes. The test foods were cookies and tofu, in amounts of 2 g and 4 g. The normalized muscle activity (integrated EMG), duration of the muscle activity, initial activation timepoint of each muscle, and total duration of swallowing were compared among four conditions. The activity of each muscle was significantly higher during the swallowing of cookies than tofu, for 4 g vs 2 g, and for cued versus spontaneous swallowing. The duration of each muscle activity, initial activation timepoint, and total duration of swallowing were significantly longer for cookies versus tofu, for 4 g vs 2 g, and for spontaneous versus cued swallowing. These results suggest that the behavior of the masticatory and swallowing muscles is affected by cued swallowing and by the consistency and amount of food.

Effects of interferential current electrical stimulation (IFCS) on mastication and swallowing function in healthy young adults: A preliminary study.

This study aimed to investigate the effects of interferential current electrical stimulation (IFCS) on masticatory and swallowing function. Twenty healthy young adults were enrolled. The measurement items were spontaneous swallowing frequency (SSF), voluntary swallowing frequency (VSF), saliva secretion volume (SSV), glucose elution volume (GEV), and velocity of chew (VOC). All participants underwent both IFCS and sham stimulation (without stimulation, sham). Two sets of independent IFCS electrodes were placed on the bilateral neck. The precise location of the upper electrodes was just below the angle of the mandible, while the lower electrodes were placed at the anterior border of the sternocleidomastoid muscle. The intensity of IFCS was determined to be one level below the perceptual threshold that all participants felt discomfort. Statistical analysis was performed using a two-way repeated measures analysis of variance. For IFCS, the results of each measurement before and during stimulation were SSF: 1.16 and 1.46, VSF: 8.05 and 8.45, SSV: 5.33 and 5.56 g, GEV: 171.75 and 208.60 mg/dL, and VOC: 87.20 and 95.20, respectively. SSF, GEV, and VOC during stimulation were significantly increased by IFCS (SSF, p = .009; GEV, p = .048; and VOC, p = .007). Following sham stimulation, the results were SSF: 1.24 and 1.34, VSF: 7.75 and 7.90, SSV: 5.65 and 6.04 g, GEV: 176.45 and 187.35 mg/dL, and VOC: 91.35 and 88.25, respectively. While no significant differences were observed in the sham group, our findings suggest that IFCS of the superior laryngeal nerve may impact not only the swallowing function but also the masticatory function.

Brain and Pharyngeal Responses Associated with Pharmacological Treatments for Oropharyngeal Dysphagia in Older Patients.

Impaired pharyngo-laryngeal sensory function is a critical mechanism for oropharyngeal dysphagia (OD). Discovery of the TRP family in sensory nerves opens a window for new active treatments for OD. To summarize our experience of the action mechanism and therapeutic effects of pharyngeal sensory stimulation by TRPV1, TRPA1 and TRPM8 agonists in older patients with OD. Summary of our studies on location and expression of TRP in the human oropharynx and larynx, and clinical trials with acute and after 2weeks of treatment with TRP agonists in older patients with OD. (1) TRP receptors are widely expressed in the human oropharynx and larynx: TRPV1 was localized in epithelial cells and TRPV1, TRPA1 and TRPM8 in sensory fibers mainly below the basal lamina. (2) Older people present a decline in pharyngeal sensory function, more severe in patients with OD associated with delayed swallow response, impaired airway protection and reduced spontaneous swallowing frequency. (3) Acute stimulation with TRP agonists improved the biomechanics and neurophysiology of swallowing in older patients with OD TRPV1 = TRPA1 > TRPM8. (4) After 2weeks of treatment, TRPV1 agonists induced cortical changes that correlated with improvements in swallowing biomechanics. TRP agonists are well tolerated and do not induce any major adverse events. TRP receptors are widely expressed in the human oropharynx and larynx with specific patterns. Acute oropharyngeal sensory stimulation with TRP agonists improved neurophysiology, biomechanics of swallow response, and safety of swallowing. Subacute stimulation promotes brain plasticity further improving swallow function in older people with OD.

STUDY OF CLINICAL PROFILE OF OROPHARYNGEAL DYSPHAGIA USING FIBEROPTIC ENDOSCOPIC EVALUATION OF SWALLOWING (FEES) TECHNIQUE

In elderly, dysphagia and its consequences have a marked effect on quality of life. Patients with oropharyngeal dysphagia shows various structural and functional alterations. Fiberoptic Endoscopic Evaluation of Swallowing (FEES) is now widely accepted method for assessment of swallowing. This study was undertaken to know the prevalence of swallowing disorders and also assess anatomical and physiological changes seen in oropharyngeal dysphagia cases. A cross sectional study was conducted in the Methods: tertiary care hospital from January 2019 to June 2020. All patients underwent FEES examination using exible breoptic nasopharyngoscope. Anatomy and physiology of the pharynx, and larynx was assessed. Presence of oropharyngeal secretions, penetration, aspiration, residue, and spontaneous swallowing was observed. In 37 patients of Oropharyngeal dysphagia mean age Results: was 53.56 years with male preponderance (73%). In our study, oropharyngeal, laryngopharyngeal and supraglottic growth (40.54%) was the most common cause of oropharyngeal dysphagia, followed by LPR (18.9%) and neurological disorders (18.9%). In 37 patients examined 43.24% cases had secretions, 40.5% cases showed penetration, 35.1% cases showed aspiration. The most common cause of oropharyngeal Conclusion: dysphagia was oropharyngeal, laryngopharyngeal and supraglottic growth and was more frequently seen in elderly patients. FEES can be used as screening procedure and gives complete assessment of pharyngeal phase of swallowing

Relevant Indicators of Consciousness after Waterbath Stunning in Turkeys and Stunning Efficiency in Commercial Conditions.

The prevalence and inter-observer repeatability of the four most valid and feasible indicators of consciousness after waterbath stunning in turkeys were evaluated before bleeding (i.e., tonic convulsion, breathing, spontaneous blinking and vocalization) and during bleeding (i.e., fluttering, breathing, spontaneous swallowing and head shaking). Furthermore, correlations between them were calculated to further understand the association between such indicators. This study compared the assessments of four observers on 7877 turkeys from 28 flocks slaughtered in eight different abattoirs. Repeatability between observers was assessed by combining the crude percentage of agreement and the Fleiss' kappa. Before bleeding, tonic seizure was observed to be not reliable under commercial conditions and spontaneous blinking and vocalization had poor repeatability. During bleeding, spontaneous swallowing was not observed and head shaking had poor repeatability. Hence, the most relevant indicators of consciousness before bleeding is breathing while during bleeding is breathing and wing flapping. Moreover, the stunning efficiency of the key electrical parameters used in the different slaughterhouses was assessed. Therefore, a refined list of indicators of the state of consciousness after waterbath stunning is proposed to be used in commercial turkey slaughterhouses to ensure consistency of controls. On the other hand, the range of the prevalence of turkeys with indicators of consciousness within a batch found before bleeding [0-16%] and after bleeding [0-18%] highlights the importance of controls.

Validação de conteúdo de protocolo de decanulação de pacientes adultos traqueostomizados

ABSTRACT Purpose Perform content validation of a decannulation protocol for tracheostomized adult patients. Methods To validate the content of the protocol developed by speech therapists, the Delphi technique was used. The 11 items of the protocol were judged by experts through rounds via e-mail and were classified as adequate, partially adequate or inadequate, in addition to providing comments and suggestions on each item. 30 speech therapists, 30 respiratory physiotherapists and 30 physicians responsible for the tracheostomy and decannulation procedure were invited. The percentage of agreement adopted was ≥ 80% and the process was interrupted when this percentage was obtained in all items. Results At the end of the process, 24 professionals participated in the third round, being 46% speech therapists, 29% physiotherapists and 25% physicians. After the experts' suggestions and comments, two items were kept as they were in the initial protocol, seven were reformulated, six were included and two were excluded. The final version of the protocol included: identification, absence of abundant secretions, characteristics of the secretion, effective cough, ability to remove secretions, tolerate the deflated cuff, aptitude in the decannulation process, level of consciousness, change of cannula to a smaller caliber, absence of current/active infection, spontaneous and effective swallowing of saliva, use of a speech valve, aptitude for occlusion of the cannula, assessment of aptitude for decannulation and objective examinations. Conclusion Through the Delphi Technique, the content of the instrument was validated, with substantial changes occurring. The next stage of instrument validation is obtaining evidence of validity in relation to the internal structure.

Effects of the GABA(B) agonist baclofen on volitional swallowing in normal subjects.

The GABA(B) receptor agonist baclofen is known to suppress the rate of spontaneous swallowing but not pharyngeal muscle contraction. The extent to which baclofen may alter volitional swallowing is not currently known. We investigated the effects of baclofen in healthy subjects, hypothesizing that baclofen exposure would alter volume-regulation and/or piecemeal deglutition behaviors during volitional swallowing attempts. Pharyngeal high-resolution manometry impedance (P-HRM-I) protocol was used to assess swallowing function of 22 healthy adult volunteers (median 29 years) who were investigated on two occasions, receiving 40 mg baclofen (oral) 1 h before study, or placebo (randomized). Standard swallow function variables recommended by the pharyngeal HRM Working Group were derived for 5ml, 10ml, and 20 ml volumes of thin and extremely thick liquid challenges. Multiple swallow behaviors, comprising two swallows <5s apart, were characterized. The spontaneous swallow rate was also determined. Baclofen exposure had no overall significant effect on swallow variables. Upper esophageal sphincter pressure was weaker during exposure to baclofen, during both the pre-deglutitive and post-deglutitive phases of the swallow (p < 0.05 during thick liquid swallows). Piecemeal swallows, where the bolus is separated in two potions, were significantly more common during 20 ml boluses (p=0.002). Baclofen decreased the frequency of piecemeal deglutition overall. Baclofen has limited to no effect on volitional swallowing measures, however, does reduce the likelihood of initiation of piecemeal deglutition to large volume challenges.

Inter-Observer Repeatability of Indicators of Consciousness after Waterbath Stunning in Broiler Chickens.

Simple SummaryWaterbath stunning is intended to induce unconsciousness until death occurs due to bleeding in poultry. However, it is not always effective. For this reason, in order to protect their welfare, it is mandatory in the European Union that the state of consciousness of broiler chickens is monitored at the exit of the waterbath, and that they do not regain consciousness before death. Ineffectively stunned birds can be re-stunned using back-up methods to avoid unnecessary pain, stress and suffering. One of the main challenges in monitoring the state of consciousness in broiler chickens after waterbath stunning is the selection of animal-based indicators ensuring consistency among assessments. The indicators should be valid, feasible and repeatable. However, only the validity and feasibility have been reported. Thus, the main goal of this research was to assess the repeatability of the most valid and feasible indicators of the state of consciousness after waterbath stunning in broilers both before bleeding (tonic seizure, breathing, spontaneous blinking and vocalization) and during bleeding (wing flapping, breathing, spontaneous swallowing and head shaking). This study proposes a refined list of indicators that could be used to assess the consciousness of broiler chickens in commercial slaughterhouses.This study evaluated the prevalence and tested the inter-observer repeatability of the most valid and feasible animal-based indicators of the state of consciousness after waterbath stunning in broilers before bleeding (tonic seizure, breathing, spontaneous blinking and vocalization) and during bleeding (wing flapping, breathing, spontaneous swallowing and head shaking). In addition, correlations among them were computed to better understand their relationship and offer insights into the reliability of such indicators. This was aimed at proposing a refined list of indicators that could be used in commercial slaughterhouses to ensure consistent assessments. This study compared the assessments of three observers of 5241 broilers from 19 batches in six different slaughterhouses. Inter-observer repeatability was assessed through the combination of the crude percentage of agreement and the Fleiss’ kappa coefficient and interpretation. Before bleeding, the results led us to recommend assessing breathing over spontaneous blinking and vocalizations and to neglect tonic seizure in commercial conditions. During bleeding, the recommended indicators are breathing, wing flapping and head shaking while spontaneous swallowing can be neglected.

SWALLOWING ACTIVATION USING SENSORY STIMULATION IN PATIENTS WITH SEVERE DISORDERS OF CONSCIOUSNESS.

ObjectiveSwallowing disorders are systematically present in patients with severe brain injury, disorders of consciousness, and subsequently poor quality of life. The study hypothesis was that taste and smell could improve swallowing function and quality of life in such patients, who are fed by gastrostomy tube.MethodsEight patients with unresponsive wakefulness syndrome were included in this study. All patients had been in a stable state for at least 2 years, and the delay between the neurological event and the study was always more than 2 years. Strong tastes and smells were selected using the Pfister olfactory classification. Taste and smell stimulations were performed every weekday, Monday to Friday, for 1 week (5 sessions) by a speech and language therapist. Evaluation of swallowing was performed before the first session and after the fifth session, and included the number of spontaneous swallows during 10 min, the presence of drooling, and spontaneous tongue and velum mobility.ResultsThe number of spontaneous swallows at the initial evaluation was 6.8 ± 5.1 n/min. At the final evaluation there was a significant increase in the number of spontaneous swallows (9.1 ± 4.1 n/min, p < 0.01).ConclusionThis clinical observation has shown that taste and smell stimulations are relevant in clinical practice to improve spontaneous swallowing.LAY ABSTRACTSwallowing disorders are systematically present in patients with severe brain injury, disorders of consciousness, and subsequent poor quality of life. The study hypothesis was that taste and smell could improve swallowing function in such patients who require exclusive feeding by gastrostomy tube. The study showed that, in patients with severe DoC, taste and smell stimulations increased the number of spontaneous swallows. Based on these findings, taste and smell stimulations could be used in clinical practice to improve swallowing function and overall quality of life.

Spontaneous Swallowing Frequency in Post-Stroke Patients with and Without Oropharyngeal Dysphagia: An Observational Study

Oropharyngeal dysphagia (OD) is a frequent complication after stroke (PSOD) that increases morbidity and mortality. Early detection of PSOD is essential to reduce morbidity and mortality in patients with acute stroke. In recent years, an association between reduced spontaneous swallowing frequency (SSF) and OD has been described. Likewise, the reduction of saliva substance P (SP) concentration has been associated with an increased risk of aspiration and a decrease in SSF. In this study we aimed to compare SSF, salivary SP concentration, hydration and nutritional status in post-stroke (PS) patients with and without OD. We included 45 acute PS patients (4.98 ± 2.80 days from stroke onset, 62.22% men, 71.78 ± 13.46 year). The Volume-Viscosity Swallowing Test (V-VST) was performed for clinical diagnosis of OD. SSF/minute was assessed through 10-min neurophysiological surface recordings including suprahyoid-electromyography and cricothyroid-accelerometry. Saliva samples were collected with a Salivette® to determine SP by ELISA. Hydration status was assessed by bioimpedance. Nutritional status was evaluated by Mini Nutritional Assessment Short Form (MNA-sf) and blood analysis. Twenty-seven PS patients (60%) had OD; 19 (40%), impaired safety of swallow. SSF was significantly reduced in PSOD, 0.23 ± 0.18 and PSOD with impaired safety, 0.22 ± 0.18 vs 0.48 ± 0.29 swallows/minute in PS without OD (PSnOD); (both p < 0.005). Nutritional risk was observed in 62.92% PSOD vs 11.11% PSnOD (p = 0.007) and visceral protein markers were also significantly reduced in PSOD (p < 0.05). Bioimpedance showed intracellular dehydration in 37.50% PSOD vs none in PSnOD. There were no differences for saliva SP concentrations. SSF is significantly reduced in PSOD in comparison with PSnOD. Acute PSOD patients present poor nutritional status, hydropenia, and high risk for respiratory complications.

High efficient fog-water harvesting via spontaneous swallowing mechanism

Inverse wettability gradient movement triggered by water droplets’ surface energy is conductive to many fields, such as droplet transport, water supply and water nanogenerator. Here, a novel phenomenon of spontaneous inverse wettability gradient movement of droplet (i.e., the “swallowing”) is revealed (with an energy transformation ratio at 64.1%) and successfully applied to a new fog-water harvester (i.e., unique gradient wire: UGW). In wetting area on UGW, the largest droplet hanging on more hydrophilic end acts as a gluttonous droplet moving towards inverse wettability to continuously coalesce other droplets and to gain kinetic energy from released surface energy of droplets, resulting in an accelerative reciprocating action like a windshield wiper. As for a given fog flow of 150 g s−1 m−2, the maximum kinetic energy and velocity of the gluttonous droplet are 1.83 μJ and 3.8 cm s−1, respectively. This process needs no extra energy consumption and realizes a high water harvest efficiency (1.83 μL cm−1 s−1). This “Swallowing” action on such UGW allows droplet to accelerate gradually, which is beneficial to power generation from surface energy, heat transfer, and fog-water harvesting, etc.

Spontaneous Swallowing Frequency, Dysphagia, and Drooling in Children With Cerebral Palsy

ObjectiveTo evaluate relationships between spontaneous swallowing frequency, dysphagia, and drooling in children with cerebral palsy. Spontaneous swallowing frequency was predicted to be inversely related to both dysphagia and drooling among children with cerebral palsy. A secondary objective compared patterns among spontaneous swallowing frequency, drooling, and age in healthy children vs children presenting with cerebral palsy. DesignCross sectional study. SettingChildren with cerebral palsy were tested at a Cerebral Palsy Reference Center in a university hospital. Healthy children were tested in their home setting. ParticipantsTwenty children with cerebral palsy were recruited from the local registry for cerebral palsy children and purposive sampling among parents. A group of 30 healthy children was recruited by purposive sampling among family, friends, and the local community. Children below 1 year of age up to 5 years of age were included in the healthy group. This age range was targeted to maximize the potential for drooling in this group. Main Outcome MeasuresBoth groups provided data on spontaneous swallowing frequency (swallows per minute, or SPM), dysphagia, and drooling. Motor impairment was documented in the children with cerebral palsy. ResultsSPM was significantly lower in children with cerebral palsy. Among children with cerebral palsy, SPM correlated significantly with dysphagia severity and trended toward a significant correlation with drooling at rest. In this subgroup, SPM was not correlated with age or degree of motor impairment. Dysphagia was significantly correlated with drooling at rest and both dysphagia and drooling at rest were correlated with degree of motor impairment. The 2 groups did not differ in the degree of drooling at rest. Among healthy children, age but not SPM demonstrated a significant inverse correlation with drooling quotient at rest. ConclusionsSpontaneous swallowing frequency is related to dysphagia and drooling in children with cerebral palsy. The pattern of relationships among spontaneous swallowing frequency and drooling is different between children with cerebral palsy and younger healthy children.

Multimodal dataset of real-time 2D and static 3D MRI of healthy French speakers

The study of articulatory gestures has a wide spectrum of applications, notably in speech production and recognition. Sets of phonemes, as well as their articulation, are language-specific; however, existing MRI databases mostly include English speakers. In our present work, we introduce a dataset acquired with MRI from 10 healthy native French speakers. A corpus consisting of synthetic sentences was used to ensure a good coverage of the French phonetic context. A real-time MRI technology with temporal resolution of 20 ms was used to acquire vocal tract images of the participants speaking. The sound was recorded simultaneously with MRI, denoised and temporally aligned with the images. The speech was transcribed to obtain phoneme-wise segmentation of sound. We also acquired static 3D MR images for a wide list of French phonemes. In addition, we include annotations of spontaneous swallowing.

Change in Spontaneous Swallowing Frequency in HNC Patients Undergoing C/RT.

This study sought to evaluate the role and trajectory of spontaneous swallowing frequency (SFA) in patients with head and neck cancer (HNC) undergoing chemoradiotherapy (C/RT).Study Design. Prospective cohort. University comprehensive cancer center. A prospective cohort of 80 patients with HNC was followed from baseline to 3 months post-C/RT. Subjects were evaluated for performance on swallowing function, functional diet consumed, weight, swallowing frequency rate, perceived xerostomia, perceived pain, and mucositis. Relationships were evaluated using univariate correlations, t tests, and repeated-measures analysis of variance. The diagnostic accuracy of SFA to express dysphagia was calculated by area under the curve (AUROC) and displayed using receiver operator characteristic curves. In general, patients with HNC demonstrated a parabolic decline in most measures over the C/RT trajectory. SFA and perceived xerostomia did not show improved recovery by 3 months. SFA was related to swallow function, xerostomia, and functional diet consumed posttreatment and pain at 3 months. The ability of SFA to correctly identify clinical dysphagia (Mann Assessment of Swallowing-Cancer version [MASA-C]) and reduced oral intake (Functional Oral Intake Scale [FOIS]) at posttreatment was strong (AUROC MASA-C: 0.824 [95% CI, 0.63-1.00], P < .0018; AUROC FOIS: 0.96 [95% CI, 0.87-0.96], P < .0001). This exploratory study suggests SFA may provide a useful method to identify dysphagia after HNC treatment. Furthermore, SFA may offer a simple, objective measure of swallowing function change in HNC over the C/RT trajectory.

Effects of Pharyngeal Electrical Stimulation on Swallow Timings, Clearance and Safety in Post-Stroke Dysphagia: Analysis from the Swallowing Treatment Using Electrical Pharyngeal Stimulation (STEPS) Trial.

Swallowing impairment (dysphagia) post-stroke results in poorer outcomes. Pharyngeal electrical stimulation (PES) is a potential treatment for post-stroke dysphagia. In a post hoc analysis, we investigated PES using videofluoroscopy swallow studies (VFSS) from the STEPS trial incorporating multiple measures of safety (penetration aspiration scale-PAS), speed and duration (timing), and efficiency (clearance), as opposed to the original trial which only measured PAS scores. 81 randomised participants (PES (N = 43) versus sham (N = 38)) were analysed at baseline and 2 weeks. Participants swallowed up to 6 × 5 ml and 1 × 50 ml of thin liquid barium at 40% w/v, images at ≥25 fps. Based on PAS, the 5 ml mode bolus (most frequently occurring PAS from 6 × 5 ml) and the worst 50 ml bolus were chosen for further analysis. Eight timing measures were performed, including stage transition duration (STD) and pharyngeal transit time (PTT). Clearance measures comprised oral and pharyngeal residue and swallows to clear. Comparisons of change of scoring outcomes between PES and sham were done at 2 weeks. Wilcoxon Signed Ranks Test was also used to evaluate longitudinal changes from both groups' combined results at two weeks. Between-group analysis showed no statistically significant differences. Issues with suboptimal image quality and frame rate acquisition affected final numbers. At two weeks, both groups demonstrated a significant improvement in most safety scores (PAS) and STD, possibly due to spontaneous recovery or a combination of spontaneous recovery and swallowing treatment and usual care. A nonsignificant trend for improvement was seen in other timing measures, including PTT. This study, which conducted additional measurements of kinematic and residue analysis on the STEPS data did not detect “missed” improvements in swallowing function that the PAS is not designed to measure. However, more studies with greater numbers are required.

Standardized Endoscopic Swallowing Evaluation for Tracheostomy Decannulation in Critically Ill Neurologic Patients \u2013 a prospective evaluation

BackgroundRemoval of a tracheostomy tube in critically ill neurologic patients is a critical issue during intensive care treatment, particularly due to severe dysphagia and insufficient airway protection. The “Standardized Endoscopic Evaluation for Tracheostomy Decannulation in Critically Ill Neurologic Patients” (SESETD) is an objective measure of readiness for decannulation. This protocol includes the stepwise evaluation of secretion management, spontaneous swallowing, and laryngeal sensitivity during fiberoptic endoscopic evaluation of swallowing (FEES). Here, we first evaluated safety and secondly effectiveness of the protocol and sought to identify predictors of decannulation success and decannulation failure.MethodsA prospective observational study was conducted in the neurological intensive care unit at Münster University Hospital, Germany between January 2013 and December 2017. Three hundred and seventy-seven tracheostomized patients with an acute neurologic disease completely weaned from mechanical ventilation were included, all of whom were examined by FEES within 72 h from end of mechanical ventilation. Using regression analysis, predictors of successful decannulation, as well as decannulation failure were investigated.ResultsTwo hundred and twenty-seven patients (60.2%) could be decannulated during their stay according to the protocol, 59 of whom within 24 h from the initial FEES after completed weaning. 3.5% of patients had to be recannulated due to severe dysphagia or related complications. Prolonged mechanical ventilation showed to be a significant predictor of decannulation failure. Lower age was identified to be a significant predictor of early decannulation after end of weaning. Transforming the binary SESETD into a 4-point scale helped predicting decannulation success in patients not immediately ready for decannulation after the end of respiratory weaning (optimal cutoff ≥1; sensitivity: 64%, specifity: 66%).ConclusionsThe SESETD showed to be a safe and efficient tool to evaluate readiness for decannulation in our patient collective of critically ill neurologic patients.

Swallowing ability and intra-oral water-retaining ability during moderate propofol sedation in healthy human volunteers: A prospective observational study.

The cough reflex or aspiration under monitored anaesthesia care might be associated with sedative-induced changes in swallowing and intra-oral water-retaining abilities. To investigate the effects of moderate propofol sedation on swallowing and intra-oral water-retaining ability. Prospective observational study. Single tertiary care centre during 2017. A total of 13 healthy adult volunteers. Volunteers in the supine position were asked to retain 10 ml of orally injected water for 5 min. After 5 minutes or when the water was spontaneously swallowed, the retention time and residual intra-oral water volume were measured. Subjects then voluntarily swallowed a further 10 ml of injected water and the residual water volume was measured. This whole process was repeated under sedation with propofol at effect-site concentrations of 0.5, 1.0 and 1.5 μg ml-1. The primary outcome was the estimated volume swallowed (swallowing volume); the secondary outcome was water retention time. Median water retention time decreased from 300 to 11 s (P < 0.001), and greater spontaneous swallowing was induced with increased propofol effect-site concentrations measuring up to 1.5 μg ml-1 (P < 0.001). The median of the estimated swallowing volumes with voluntary swallowing while awake and with all three concentrations of propofol were 9.5, 9.6, 9.6 and 9.4 ml, respectively (P = 0.805); more water remained after spontaneous swallowing than after voluntary swallowing at all concentrations. Differences in mean estimated swallowing volumes between voluntary and spontaneous swallowing were 3.4 ml (95% CI, 0.9 to 6.0, P = 0.016) for 0.5 μg ml-1, 4.1 ml (95% CI, 1.8 to 6.3, P = 0.002) for 1.0 μg ml-1 and 5.1 ml (95% CI, 3.4 to 6.8, P < 0.001) for 1.5 μg ml-1. Moderate propofol sedation decreases water-retaining ability but has no effect on voluntary swallowing. Ensuring that patients can respond under sedation may effectively prevent the unexpected cough reflex and aspiration by enabling occasional voluntary swallowing. UMIN Clinical Trials Registry identifier: UMIN000027517.

Effect of Aging, Gender and Sensory Stimulation of TRPV1 Receptors with Capsaicin on Spontaneous Swallowing Frequency in Patients with Oropharyngeal Dysphagia: A Proof-of-Concept Study.

Spontaneous swallowing contributes to airway protection and depends on the activation of brainstem reflex circuits in the central pattern generator (CPG). We studied the effect of age and gender on spontaneous swallowing frequency (SSF) in healthy volunteers and assessed basal SSF and TRPV1 stimulation effect on SSF in patients with post-stroke oropharyngeal dysphagia (OD). The effect of age and gender on SSF was examined on 141 healthy adult volunteers (HV) divided into three groups: GI—18–39 yr, GII—40–59 yr, and GIII—>60 yr. OD was assessed by the Volume–Viscosity Swallowing Test (VVST). The effect of sensory stimulation with capsaicin 10−5 M (TRPV1 agonist) was evaluated in 17 patients with post-stroke OD, using the SSF. SSF was recorded in all participants during 10 min using surface electromyography (sEMG) of the suprahyoid muscles and an omnidirectional accelerometer placed over the cricothyroid cartilage. SSF was significantly reduced in GII (0.73 ± 0.50 swallows/min; p = 0.0385) and GIII (0.50 ± 0.31 swallows/min; p < 0.0001) compared to GI (1.03 ± 0.62 swallows/min), and there was a moderate significant correlation between age and SFF (r = −0.3810; p < 0.0001). No effect of gender on SSF was observed. Capsaicin caused a strong and significant increase in SSF after the TRPV1 stimulation when comparing to basal condition (pre-capsaicin: 0.41 ± 0.32 swallows/min vs post-capsaicin: 0.81 ± 0.51 swallow/min; p = 0.0003). OD in patients with post-stroke OD and acute stimulation with TRPV1 agonists caused a significant increase in SSF, further suggesting the potential role of pharmacological stimulation of sensory pathways as a therapeutic strategy for CPG activation in patients with OD.