The Experts below are selected from a list of 14544 Experts worldwide ranked by ideXlab platform
Manuel G. Cosio - One of the best experts on this subject based on the ideXlab platform.
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Relationship of Resting Lung Mechanics and Exercise Pattern of Breathing in Patients With Chronic Obstructive Lung Disease
Chest, 1993Co-Authors: Jose M Marin, Robert D Levy, W J Gibbons, Mario Polverino, Sabah N. A. Hussain, Manuel G. CosioAbstract:To investigate the influence of resting pulmonary mechanics on the Pattern of Breathing during exercise in chronic obstructive pulmonary disease (COPD), we studied 29 patients with moderate to severe COPD (FEV 1 50±20 percent predicted), and 10 normal subjects. Lung mechanics were studied using esophageal balloon technique and body-box. Incremental exercise testing was performed to exhaustion. As minute ventilation ( V ˙ O 2 ) increases, COPD patients with the highest pulmonary resistance (Rl) or lowest elastic recoil pressure (Pl), used a greater tidal volume/vital capacity ratio ( V ˙ O 2 /VC) than the COPD patients with more normal Rl or lowest Pl. To describe the Breathing Pattern during exercise, an exponential constant (K) describes the rates of increase in Vt/VC ratio with increasing V ˙ O 2 , calculated according to the equation Vt=VC(1—e – V ˙ O 2 ). The K values achieved by COPD patients were higher than in normal subjects. In addition, K value correlated negatively with the resting FEV 1 and FVC of COPD patients. When COPD patients were grouped according to their K values, it was revealed that patients with high K values generated greater Vt/VC ratio and also have the most abnormal resting lung mechanics. These results suggest that the exercise Breathing Pattern in COPD patients is significantly influenced by the degree of impairment of resting lung mechanics.
Maurizio Ferretti - One of the best experts on this subject based on the ideXlab platform.
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effects of distancing and Pattern of Breathing on the filtering capability of commercial and custom made facial masks an in vitro study
PLOS ONE, 2021Co-Authors: Lorenzo Ball, Stefano Alberti, Claudio Belfortini, Chiara Almondo, Chiara Robba, Denise Battaglini, Carlo Cravero, Paolo Pelosi, Valentina Caratto, Maurizio FerrettiAbstract:BACKGROUND: Since the beginning of the COVID-19 pandemics, masking policies have been advocated. While masks are known to prevent transmission towards other individuals, it is unclear if different types of facial masks can protect the user from inhalation. The present study compares in-vitro different commercial and custom-made facial masks at different distances and Breathing Patterns. METHODS: Masks were placed on a head mannequin connected to a lung simulator, using a collecting filter placed after the mannequin airway. Certified, commercial and custom-made masks were tested at three different distances between the emitter and the mannequin: 40 cm, 80 cm and 120 cm. Two Patterns of Breathing were used, simulating normal and polypneic respiration. A solution of methylene blue was nebulized with a jet nebulizer and different mask-distance-Breathing Pattern combinations were tested. The primary endpoint was the inhaled fraction, defined as the amount of methylene blue detected with spectrophotometry expressed as percent of the amount detected in a reference condition of zero distance and no mask. FINDINGS: We observed a significant effect of distance (p < 0.001), Pattern of Breathing (p = 0.040) and type of mask (p < 0.001) on inhaled fraction. All masks resulted in lower inhaled fraction compared to Breathing without mask (p < 0.001 in all comparisons), ranging from 41.1% ± 0.3% obtained with a cotton mask at 40 cm distance with polypneic Pattern to <1% for certified FFP3 and the combination of FFP2 + surgical mask at all distances and both Breathing Pattern conditions. DISCUSSION: Distance, type of device and Breathing Pattern resulted in highly variable inhaled fraction. While the use of all types of masks resulted relevantly less inhalation compared to distancing alone, only high-grade certified devices (FFP3 and the combination of FFP2 + surgical mask) ensured negligible inhaled fraction in all conditions.
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Effects of distancing and Pattern of Breathing on the filtering capability of commercial and custom-made facial masks: An in-vitro study.
'Public Library of Science (PLoS)', 2021Co-Authors: Lorenzo Ball, Stefano Alberti, Claudio Belfortini, Chiara Almondo, Chiara Robba, Denise Battaglini, Carlo Cravero, Paolo Pelosi, Valentina Caratto, Maurizio FerrettiAbstract:BackgroundSince the beginning of the COVID-19 pandemics, masking policies have been advocated. While masks are known to prevent transmission towards other individuals, it is unclear if different types of facial masks can protect the user from inhalation. The present study compares in-vitro different commercial and custom-made facial masks at different distances and Breathing Patterns.MethodsMasks were placed on a head mannequin connected to a lung simulator, using a collecting filter placed after the mannequin airway. Certified, commercial and custom-made masks were tested at three different distances between the emitter and the mannequin: 40 cm, 80 cm and 120 cm. Two Patterns of Breathing were used, simulating normal and polypneic respiration. A solution of methylene blue was nebulized with a jet nebulizer and different mask-distance-Breathing Pattern combinations were tested. The primary endpoint was the inhaled fraction, defined as the amount of methylene blue detected with spectrophotometry expressed as percent of the amount detected in a reference condition of zero distance and no mask.FindingsWe observed a significant effect of distance (p DiscussionDistance, type of device and Breathing Pattern resulted in highly variable inhaled fraction. While the use of all types of masks resulted relevantly less inhalation compared to distancing alone, only high-grade certified devices (FFP3 and the combination of FFP2 + surgical mask) ensured negligible inhaled fraction in all conditions
H Hamilton - One of the best experts on this subject based on the ideXlab platform.
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Pattern of Breathing and upper airway mechanics during wakefulness and sleep in healthy elderly humans
Journal of Applied Physiology, 1993Co-Authors: David W Hudgel, Prema Devadatta, H HamiltonAbstract:Elderly subjects are known to be prone to periodic Breathing in sleep. Because periodic Breathing may be associated with changes in upper airway caliber, we hypothesized that oscillations in upper airway caliber contribute to the increased prevalence of sleep-related periodic Breathing in the elderly. We tested this hypothesis by measuring upper airway resistance, ventilatory variables, and the Pattern of variation of these variables in groups of body size-matched young and elderly healthy individuals during wakefulness and stage 2 non-rapid-eye-movement sleep. No major differences existed between the two groups during either wakefulness or sleep in mean upper airway resistance or ventilation values. However, ventilation was more variable during sleep in the elderly; this variability was oscillatory in the majority of elderly subjects at an average rate of 0.04 breaths/cycle or one cycle approximately every 24 s. Oscillations in upper airway resistance during sleep were associated with reciprocal oscillations in tidal volume and/or minute ventilation at the same frequency. Those subjects who had significant oscillations in upper airway resistance had more apneas and hypopneas than those subjects without such oscillations. Oscillations in resistance and ventilation occurred in the supine but not in the lateral body position. We conclude that the wide oscillations in upper airway resistance present during sleep in supine healthy elderly subjects produce a fluctuating mechanical limitation of ventilation, which may contribute to periodic Breathing.
Laurent Storme - One of the best experts on this subject based on the ideXlab platform.
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influence of three nasal continuous positive airway pressure devices on Breathing Pattern in preterm infants
Archives of Disease in Childhood-fetal and Neonatal Edition, 2007Co-Authors: Hocine Boumecid, Thameur Rakza, Abdel Abazine, Serge Klosowski, Regis Matran, Laurent StormeAbstract:The Pattern of Breathing was studied in 13 premature newborns treated by variable-flow Nasal Continuous Positive Airway Pressure (NCPAP), conventional NCPAP, and nasal cannulae. Compared to constant-flow NCPAP and nasal cannulae, the variable-flow NCPAP increases tidal volume and improves thoraco-abdominal synchrony, suggesting that variable-flow NCPAP provides more effective ventilatory support than conventional NCPAP or nasal cannulae.
Massimo Pistolesi - One of the best experts on this subject based on the ideXlab platform.
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gas exchange and Breathing Pattern in women with postmenopausal bone fragility
Respiratory Medicine, 2018Co-Authors: Francesca Polverino, J P De Torres, Carlo Santoriello, Antonio Capuozzo, Immacolata Mauro, Joselyn Rojasquintero, Bruno Dagostino, Massimo Pistolesi, Bartolome R CelliAbstract:BACKGROUND Little is known about the relationship between bone fragility and respiratory function. We hypothesized that women with osteoporosis or osteopenia, without cardio-pulmonary disease, have perturbations in the Pattern of Breathing and gas exchange. METHODS In 44 women with bone fragility (BF, T score: -1) we compared pulmonary function tests, central respiratory drive (mouth occlusion pressure or P 0.1), Pattern of Breathing using optoelectronic plethysmograph and arterial blood gases at rest. RESULTS Static pulmonary function was similar in BF subjects and controls. However, the arterial blood gas measurements differed significantly. The arterial pH was significantly higher in BF subjects than in controls (P < 0.001). The partial pressure of carbon dioxide (PaCO2) and oxygen (PaO2) in arterial blood were significantly lower in BF subjects than controls (P < 0.001 and P = 0.009, respectively). The BF subjects had a shorter inspiratory fraction compared with controls (P = 0.036). Moreover, T-scores were significantly inversely correlated with the alveolar-arterial gradient of oxygen (r = -0.5; P = 0.0003) and the arterial pH (r = -0.4; P = 0.002), and positively correlated with arterial PaO2 (r = 0.3; P = 0.01) and PaCO2 (r = 0.4; P = 0.002) among all subjects. CONCLUSION In the absence of known cardio-pulmonary disease, BF is associated with statistically significant perturbations in gas exchange and alterations in the Pattern of Breathing including shortening of the inspiratory time.
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fog induced respiratory responses are attenuated by nedocromil sodium in humans
American Journal of Respiratory and Critical Care Medicine, 2001Co-Authors: Federico Lavorini, Giovanni A Fontana, Tito Pantaleo, Gianna Camiciottoli, W Castellani, Nazzarena M Maluccio, Massimo PistolesiAbstract:Fog inhalation induces cough and bronchoconstriction in patients with asthma, but only cough in normal subjects; whether it also influences the Pattern of Breathing is unclear. Nedocromil sodium (NCS) inhibits the cough response to inhalation of several pharmacological agents but its effects on fog-induced cough and changes in the Pattern of Breathing are unknown. We evaluated the effects of no drug, placebo, and 4- and 8-mg NCS administration on the cough threshold and changes in the Pattern of Breathing during fog inhalation in 14 healthy subjects. Measurements of tidal volume (Vt), duration of inspiratory and expiratory times (Ti and Te, respectively), total duration of the respiratory cycle (Tt), mean inspiratory flow (Vt/Ti), duty cycle (Ti/Tt), respiratory frequency (f, 60/Tt), and inspiratory minute ventilation (V˙ i) were obtained by inductive plethysmography. Median cough threshold values were unaffected by placebo, but were increased (p < 0.01) by both NCS doses. In no-drug and placebo trials, i...
