ロートを用いた客観的な簡易とろみ評価方法の開発

Some patients with dysphagia are prone to aspiration of low-viscosity liquids. Thickened liquids are often used in attempts to prevent aspiration. The patients should be given thickened liquids with suitable thickness, and the thickness should be constant at all time. While rotational and cone-and-plate viscometers are used for the evaluation of thickened liquids, they are high-precision and expensive equipment. To control the thickness of liquids, a simple and objective evaluation method is thus necessary. We developed a method to evaluate thickened liquids using funnels, and verified the appropriateness of this method. We measured the outflow times of five thickened liquids through funnels. One of the thickened liquids was a commercially available nutritional supplement, another was made with a thickening agent that contained guar gum, and all others were made with a thickening agent that contained xanthan gum. Four funnels with different stem sizes were tested. We found that the outflow time of thickened liquids through a funnel depended on their viscosities at a shear rate between 10 and 50 s–1, when the average inner diameter of the stem was in the range of 5.3–9.0 mm, and the volume of the liquid poured into the funnel was 30 mL. The correlation coefficient between the value of the sensory evaluation and the outflow time of the funnel with an average stem ID of 5.3 mm was 0.946. Therefore, this method may be useful in hospital and nursing home kitchens for evaluating thickened liquids

Videofluoroscopic Swallowing Study of Esophageal Cancer Cases

Aims: To determine suitable food textures for videofluoroscopic study of swallowing (VFSS), in order to predict and prevent subsequent aspiration pneumonia in esophageal cancer patients with dysphagia after surgery. Methods: We evaluated 45 hospitalized esophageal cancer patients who underwent surgery between January 2012 and December 2013. The control group consisted of 43 patients who underwent surgery between January 2010 and December 2011 and were not examined by VFSS. Test foods, which were presented in order of increasing thickness, included thin barium sulfate (Ba) liquid (3 or 10 ml), slightly thickened Ba liquid (3 or 10 ml), a spoonful of Ba jelly, and a spoonful of Ba puree. Results: Patients could most safely swallow puree, followed by jelly. The 3-mL samples of both the thin and thick liquids put patients at risk for aspiration pneumonia, with incidence rates of 13% and 11%, respectively. While 64.4% of patients could swallow all test foods and liquids safely, 35.6% were at risk for aspiration pneumonia when swallowing liquids. Even though >30% of patients were at risk, only 1 (2.2%) in the VFSS group developed aspiration pneumonia, which occurred at the time of admission. Following VFSS, no incidence of aspiration pneumonia was observed. However, aspiration pneumonia occurred in 4 (9.3%) control patients during hospitalization. Conclusions: Postoperative esophageal cancer patients were more likely to aspirate any kind of liquid than solid foods, such as jellies. VFSS is very useful to determine suitable food textures for postoperative esophageal cancer patients

Inappropriate Timing of Swallow in the Respiratory Cycle Causes Breathing–Swallowing Discoordination

Rationale: Swallowing during inspiration and swallowing immediately followed by inspiration increase the chances of aspiration and may cause disease exacerbation. However, the mechanisms by which such breathing-swallowing discoordination occurs are not well-understood. Objectives: We hypothesized that breathing-swallowing discoordination occurs when the timing of the swallow in the respiratory cycle is inappropriate. To test this hypothesis, we monitored respiration and swallowing activity in healthy subjects and in patients with dysphagia using a non-invasive swallowing monitoring system. Measurements and Main Results: The parameters measured included the timing of swallow in the respiratory cycle, swallowing latency (interval between the onset of respiratory pause and the onset of swallow), pause duration (duration of respiratory pause for swallowing), and the breathing-swallowing coordination pattern. We classified swallows that closely follow inspiration (I) as I-SW, whereas those that precede I as SW-I pattern. Patients with dysphagia had prolonged swallowing latency and pause duration, and tended to have I-SWor SW-I patterns reflecting breathing-swallows discoordination. Conclusions: We conclude that swallows at inappropriate timing in the respiratory cycle cause breathing-swallowing discoordination, and the prolongation of swallowing latency leads to delayed timing of the swallow, and results in an increase in the SW-I pattern in patients with dysphagia

Slab geometry type cold neutron moderator development based on neutronic study for Riken Accelerator-driven compact Neutron Source (RANS)

Cold neutrons with energy less than several meV are good probes for material research, and they have been available on large neutron facilities, whereas it is not commonly available on compact accelerator-driven neutron source. RIKEN Accelerator-driven Neutron Source (RANS) is a pulsed neutron facility which provides thermal neutrons and high energy neutrons at several MeV. We started a project to implement a cold neutron moderator for RANS to broaden cold neutrons applications. A cold neutron moderator system with a mesitylene moderator at 20K and a polyethylene pre-moderator at room temperature in the slab geometry was designed for RANS. So far, the thickness of the pre-moderator and mesitylene have been optimized to get the highest cold neutron flux by using a Monte Carlo simulation code, PHITS. Graphite reflector dimensions were also proven to have significant effect to increase the cold neutron intensity

Breathing–swallowing discoordination is associated with frequent exacerbations of COPD

[Introduction] Impaired coordination between breathing and swallowing (breathing–swallowing discoordination) may be a significant risk factor for the exacerbation of chronic obstructive pulmonary disease (COPD). We examined breathing–swallowing discoordination in patients with COPD using a noninvasive and quantitative technique and determined its association with COPD exacerbation. [Methods] We recruited 65 stable outpatients with COPD who were enrolled in our prospective observational cohort study and did not manifest an apparent swallowing disorder. COPD exacerbation was monitored for 1 year before and 1 year after recruitment. Swallowing during inspiration (the I-SW pattern) and swallowing immediately followed by inspiration (the SW-I pattern) were identified. [Results] The mean frequency of the I-SW and/or SW-I patterns (I-SW/SW-I rate) was 21.5%±25.5%. During the 2-year observation period, 48 exacerbation incidents (25 patients) were identified. The I-SW/SW-I rate was significantly associated with the frequency of exacerbation. During the year following recruitment, patients with a higher I-SW/SW-I frequency using thicker test foods exhibited a significantly higher probability of future exacerbations (p=0.002, log-rank test). [Conclusions] Breathing–swallowing discoordination is strongly associated with frequent exacerbations of COPD. Strategies that identify and improve breathing– swallowing coordination may be a new therapeutic treatment for patients with COPD