体圧分散エアマットレスにおける姿勢と硬さの変化が、嚥下障害を有する高齢者の咳嗽力に与える影響

広島大学(Hiroshima University)博士(保健学)Doctor of Philosophy in Health Sciencedoctora

Effect of Different Levels of Pressure Relieving Air-Mattress Firmness on Cough Strength.

Cough is an important host-defense mechanism. The elderly and patients who are severely ill cannot cough effectively when lying in the supine position. Furthermore, pressure relieving air-mattresses are recommended for preventing the development of pressure ulcers. In this study, we clarified whether or not the cough peak flow (CPF), an index of cough strength, is affected by different firmness levels of a pressure relieving air-mattress in healthy volunteers in the supine position. Fifty-two healthy young men participated. All the measurements were carried out on each participant in the supine position on a pressure relieving air-mattress. The participants were assessed at two firmness levels, a "hard" and "soft" mode. The CPF, forced vital capacity (FVC), maximal expiratory pressure (PEmax), and maximal inspiratory pressure (PImax) were determined for each mode. The sinking distance of the body into the mattress was measured without any activity and the difference between the sinking distances of the two firmness levels was determined. The CPF, FVC, PEmax, and PImax were determined for each mode. The sinking distance of the body into the mattress was measured and the difference between the sinking distances of the two firmness levels was determined. The CPF, FVC, PEmax and PImax values of the participants coughing on the mattress were significantly lower when the mattress was in "soft" than in "hard" mode. The differences between the sinking distances of the mattress in "soft" and "hard" modes were larger for the anterior superior iliac spine. A harder mattress may lead to increased CPF in healthy young men lying in the supine position, and increased CPF may be important for host defense

Posture and firmness changes in a pressure-relieving air mattress affect cough strength in elderly people with dysphagia.

Dysphagia is the major pathophysiologic mechanism leading to aspiration pneumonia in the elderly. Elderly people with dysphagia who show low levels of the cough peak flow (CPF) are at greater risk for aspiration pneumonia. It has been reported that CPF values were significantly lower in the "soft" versus "hard" mode of a pressure-relieving air mattress in healthy volunteers in a supine position. Parameters such as spinal curvature, however, were not evaluated in detail. In this study, we clarified whether the changes in posture associated with two different firmness levels of a pressure-relieving air mattress were associated with cough production and related factors in the elderly with dysphagia. The body sinking distance, pelvic tilt angle, and immersion of the lumbar spine were measured to evaluate changes in posture. Forty subjects met the study criteria for dysphagia. The "soft" mode showed significantly lower CPF values than the "hard" mode (soft 274.9 ± 107.2 L/min vs. hard 325.0 ± 99.5 L/min, MD 50.0 95%CI 33.1-66.9 P < 0.001). Values of forced vital capacity (FVC) and maximal inspiratory pressure (PImax) were significantly lower in the "soft" mode than in the "hard" mode (MD 0.10 95%CI 0.04-0.17, P = 0.002, MD 3.2 95%CI 0.9-5.5, P = 0.007, respectively). Although there was no significant difference between the two firmness levels, maximal expiratory pressure (PEmax) values also tended to be lower in the "soft" than in the "hard" mode, (MD 2.9 95%CI -0.6-6.3 P = 0.1). At both firmness levels, CPF values were significantly correlated with FVC, PImax, and PEmax. The difference in sinking distance in the anterior superior iliac spine was significantly larger than that in the lesser tubercle of the humerus and patella. Additionally, in the soft mode, the pelvic tilt angle and contact area around the lumbar spine were significantly larger than those observed in the "hard" mode. Parameters associated with the production of cough, including inspiratory muscle strength, lung volume, and ultimately CPF, may be affected by immersion of the lumbar spine and curvature of the spine that results from the "soft" mode in elderly patients with dysphagia

L-cysteine improves blood fluidity impaired by acetaldehyde: In vitro evaluation.

Blood fluidity is reportedly influenced by the volume and function of blood cells and plasma and is a predictor of primary cardiovascular events in patients with traditional cardiovascular risk factors. Heavy alcohol consumption was shown to be associated with a higher risk for cardiovascular diseases. Acetaldehyde (ACD), an oxidizing substance formed from ethanol, reportedly stimulates monocyte adhesion, causes abnormalities in the red blood cell (RBC) membrane, and decreases RBC deformability. In addition, it was reported that blood ACD levels are reduced in mice pretreated with L-cysteine. However, there are no studies on the effect of ACD and/or L-cysteine on blood fluidity. In the present study, we evaluated whether ACD impairs blood fluidity. In addition, the effect of L-cysteine on blood fluidity impaired by ACD was examined. Blood samples were obtained from 10 healthy, non-smoking, male volunteers (age: 23.4 ± 1.2 years, body mass index: 21.8 ± 2.6 kg/m2). ACD or ACD and L-cysteine were added to the blood samples before each experiment. We measured the passage time of 100 μL blood and RBC suspension using Kikuchi's microchannel method. Percentage of microchannel obstruction and the number of adherent white blood cells (WBCs) on microchannel terrace were counted. The blood passage time, percentage of microchannel obstruction, and numbers of adherent WBCs on the microchannel terrace increased after adding ACD in a concentration-dependent manner, whereas they decreased after adding ACD and L-cysteine in a L-cysteine concentration-dependent manner. No significant effects were observed in passage time for 100 μL RBC suspension after adding ACD and L-cysteine. This study suggested that blood fluidity impaired by ACD might improve after adding L-cysteine