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https://www.readbyqxmd.com/read/29054325/use-of-ideal-alveolar-air-equations-and-corrected-end-tidal-pco2-to-estimate-arterial-pco2-and-physiological-dead-space-during-exercise-in-patients-with-heart-failure
#1
Erik H Van Iterson, Thomas P Olson
BACKGROUND: Arterial CO2 tension (PaCO2) and physiological dead space (VD) are not routinely measured during clinical cardiopulmonary exercise testing (CPET). Abnormal changes in PaCO2 accompanied by increased VD directly contribute to impaired exercise ventilatory function in heart failure (HF). Because arterial catheterization is not standard practice during CPET, this study tested the construct validity of PaCO2 and VD prediction models using 'ideal' alveolar air equations and basic ventilation and gas-exchangegas exchange measurements during CPET in HF...
October 7, 2017: International Journal of Cardiology
https://www.readbyqxmd.com/read/29051332/parenchymal-strain-heterogeneity-during-oscillatory-ventilation-why-two-frequencies-are-better-than-one
#2
Jacob Herrmann, Merryn H Tawhai, David W Kaczka
High frequency oscillatory ventilation (HFOV) relies on low tidal volumes cycled at supraphysiologic rates, producing fundamentally different mechanisms for gas transport and exchange compared with conventional mechanical ventilation. Despite the appeal of using low tidal volumes to mitigate the risks of ventilator-induced lung injury (VILI), HFOV has not improved mortality for most clinical indications. This may be due to non-uniform and frequency-dependent distribution of flow throughout the lung. The goal of this study was to compare parenchymal strain heterogeneity during eucapnic HFOV when using oscillatory waveforms that consisted of either a single discrete frequency or two simultaneous frequencies...
October 19, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/29049136/comparisons-of-traditional-metabolic-markers-and-compensatory-reserve-as-early-predictors-of-tolerance-to-central-hypovolemia-in-humans
#3
Alicia M Schiller, Jeffrey T Howard, Kristen R Lye, Christian G Magby, Victor A Convertino
Circulatory shock remains a leading cause of death in both military and civilian trauma. Early, accurate and reliable prediction of decompensation is necessary for the most efficient interventions and clinical outcomes. Individual tolerance to reduced central blood volume can serve as a model to assess the sensitivity and specificity of vital sign measurements. The compensatory reserve (CRM) is the measurement of this capacity. Measurements of muscle oxygen saturation (SmO2), blood lactate and end tidal CO2 (EtCO2) have recently gained attention as prognostic tools for early assessment of the status of patients with progressive hemorrhage, but lack the ability to adequately differentiate individual tolerance to hypovolemia...
October 18, 2017: Shock
https://www.readbyqxmd.com/read/29043834/higher-peep-versus-lower-peep-strategies-for-patients-with-acute-respiratory-distress-syndrome-a-systematic-review-and-meta-analysis
#4
Allan J Walkey, Lorenzo Del Sorbo, Carol Hodgson, Neill Kj Adhikari, Hannah Wunsch, Maureen O Meade, Elizabeth Uleryk, Dean Hess, Daniel S Talmor, B Taylor Thompson, Roy G Brower, Eddy Fan
RATIONALE: Higher positive end-expiratory pressure (PEEP) levels may reduce atelectrauma but increase over-distention lung injury. Whether higher PEEP improves clinical outcomes among patients with acute respiratory distress syndrome (ARDS) is unclear. OBJECTIVE: To compare clinical outcomes of mechanical ventilation strategies using higher PEEP levels versus lower PEEP strategies in patients with ARDS. METHODS: We performed a systematic review and meta-analysis of clinical trials investigating mechanical ventilation strategies using higher versus lower PEEP levels...
October 18, 2017: Annals of the American Thoracic Society
https://www.readbyqxmd.com/read/29043832/high-frequency-oscillation-for-adult-patients-with-acute-respiratory-distress-syndrome-a-systematic-review-and-meta-analysis
#5
Ewan Goligher, Laveena Munshi, Neill Kj Adhikari, Maureen O Meade, Carol Hodgson, Hannah Wunsch, Elizabeth Uleryk, Ognjen Gajic, Marcelo Amato, Niall D Ferguson, Gordon D Rubenfeld, Eddy Fan
RATIONALE: By minimizing tidal lung strain and maintaining alveolar recruitment, high frequency oscillatory ventilation (HFOV) may protect against ventilator-induced lung injury. OBJECTIVES: To summarize the current evidence in support of the use of HFOV in adult patients with ARDS. METHODS: We conducted a systematic review and meta-analysis of randomized trials comparing mortality rates with the use of HFOV vs. conventional mechanical ventilation for adult patients with acute respiratory distress syndrome...
October 18, 2017: Annals of the American Thoracic Society
https://www.readbyqxmd.com/read/29039883/volume-targeted-versus-pressure-limited-ventilation-in-neonates
#6
REVIEW
Claus Klingenberg, Kevin I Wheeler, Naomi McCallion, Colin J Morley, Peter G Davis
BACKGROUND: Damage caused by lung overdistension (volutrauma) has been implicated in the development of bronchopulmonary dysplasia (BPD). Modern neonatal ventilation modes can target a set tidal volume as an alternative to traditional pressure-limited ventilation (PLV) using a fixed inflation pressure. Volume-targeted ventilation (VTV) aims to produce a more stable tidal volume in order to reduce lung damage and stabilise the partial pressure of carbon dioxide (pCO2). OBJECTIVES: To determine whether VTV compared with PLV leads to reduced rates of death and death or BPD in newborn infants and to determine whether use of VTV affected outcomes including air leak, cranial ultrasound findings and neurodevelopment...
October 17, 2017: Cochrane Database of Systematic Reviews
https://www.readbyqxmd.com/read/29026971/is-impaired-cerebral-vasoreactivity-an-early-marker-of-cognitive-decline-in-multiple-sclerosis-patients
#7
Aude Metzger, Emmanuelle Le Bars, Jeremy Deverdun, François Molino, Bénédicte Maréchal, Marie-Christine Picot, Xavier Ayrignac, Clarisse Carra, Luc Bauchet, Alexandre Krainik, Pierre Labauge, Nicolas Menjot de Champfleur
OBJECTIVE: The link between cerebral vasoreactivity and cognitive status in multiple sclerosis remains unclear. The aim of the present study was to investigate a potential decrease of cerebral vasoreactivity in multiple sclerosis patients and correlate it with cognitive status. METHODS: Thirty-three patients with multiple sclerosis (nine progressive and 24 remitting forms, median age: 39 years, 12 males) and 22 controls underwent MRI with a hypercapnic challenge to assess cerebral vasoreactivity and a neuropsychological assessment...
October 12, 2017: European Radiology
https://www.readbyqxmd.com/read/28993497/marine-biorhythms-bridging-chronobiology-and-ecology
#8
Martin Bulla, Thomas Oudman, Allert I Bijleveld, Theunis Piersma, Charalambos P Kyriacou
Marine organisms adapt to complex temporal environments that include daily, tidal, semi-lunar, lunar and seasonal cycles. However, our understanding of marine biological rhythms and their underlying molecular basis is mainly confined to a few model organisms in rather simplistic laboratory settings. Here, we use new empirical data and recent examples of marine biorhythms to highlight how field ecologists and laboratory chronobiologists can complement each other's efforts. First, with continuous tracking of intertidal shorebirds in the field, we reveal individual differences in tidal and circadian foraging rhythms...
November 19, 2017: Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences
https://www.readbyqxmd.com/read/28977760/sediment-trapping-in-estuaries
#9
Hans Burchard, Henk M Schuttelaars, David K Ralston
Estuarine turbidity maxima (ETMs) are generated by a large suite of hydrodynamic and sediment dynamic processes, leading to longitudinal convergence of cross-sectionally integrated and tidally averaged transport of cohesive and noncohesive suspended particulate matter (SPM). The relative importance of these processes for SPM trapping varies substantially among estuaries depending on topography, fluvial and tidal forcing, and SPM composition. The high-frequency dynamics of ETMs are constrained by interactions with the low-frequency dynamics of the bottom pool of easily erodible sediments...
October 4, 2017: Annual Review of Marine Science
https://www.readbyqxmd.com/read/28966348/x-rays-from-the-location-of-the-double-humped-transient-asassn-15lh
#10
R Margutti, B D Metzger, R Chornock, D Milisavljevic, E Berger, P K Blanchard, C Guidorzi, G Migliori, A Kamble, R Lunnan, M Nicholl, D L Coppejans, S Dall'Osso, M R Drout, R Perna, B Sbarufatti
We present the detection of persistent soft X-ray radiation with Lx ~ 10(41)-10(42) erg s(-1) at the location of the extremely luminous, double-humped transient ASASSN-15lh as revealed by Chandra and Swift. We interpret this finding in the context of observations from our multiwavelength campaign, which revealed the presence of weak narrow nebular emission features from the host-galaxy nucleus and clear differences with respect to superluminous supernova optical spectra. Significant UV flux variability on short timescales detected at the time of the rebrightening disfavors the shock interaction scenario as the source of energy powering the long-lived UV emission, while deep radio limits exclude the presence of relativistic jets propagating into a low-density environment...
February 10, 2017: Astrophysical Journal
https://www.readbyqxmd.com/read/28962079/corilagin-protects-the-acute-lung-injury-by-ameliorating-the-apoptosis-pathway
#11
Shixun Guo, Yun Fu, Shenming Xiong, Jiudi Lv
This study elucidates the protective effect of corilagin in acute lung injury rat model. Lung injury induced by ischemia/reperfusion (I/R) model was established by isolating the lungs from the rats. Ischemia was produced for the duration of 1h and thereafter reperfusion was done for 90min in isolated lung in presence and absence of corilagin (20 and 40mg/ml). Effect of corilagin was evaluated by estimating the pulmonary vein oxygen partial pressure (PaO2), airway compliance and tidal volume. Moreover the level of oxidative stress parameter, pro inflammatory parameters, phosphorylation of JNK and apoptosis rate was estimated in lung tissues...
September 25, 2017: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
https://www.readbyqxmd.com/read/28952155/sensorimotor-control-of-breathing-in-the-mdx-mouse-model-of-duchenne-muscular-dystrophy
#12
David P Burns, Arijit Roy, Eric F Lucking, Fiona B McDonald, Sam Gray, Richard J Wilson, Deirdre Edge, Ken D O'Halloran
Patients with Duchenne muscular dystrophy (DMD) hypoventilate with consequential arterial blood gas derangement relevant to disease progression. Whereas deficits in DMD diaphragm are recognized, there is a paucity of knowledge in respect of the neural control of breathing in dystrophinopathies. We sought to perform an analysis of respiratory control in a model of DMD, the mdx mouse. In eight week old male wild-type and mdx mice, ventilation and metabolism, carotid body afferent activity, and diaphragm muscle force-generating capacity, and muscle fibre size, distribution and centronucleation were determined...
September 26, 2017: Journal of Physiology
https://www.readbyqxmd.com/read/28944062/coupling-spectral-analysis-and-hidden-markov-models-for-the-segmentation-of-behavioural-patterns
#13
Karine Heerah, Mathieu Woillez, Ronan Fablet, François Garren, Stéphane Martin, Hélène De Pontual
BACKGROUND: Movement pattern variations are reflective of behavioural switches, likely associated with different life history traits in response to the animals' abiotic and biotic environment. Detecting these can provide rich information on the underlying processes driving animal movement patterns. However, extracting these signals from movement time series, requires tools that objectively extract, describe and quantify these behaviours. The inference of behavioural modes from movement patterns has been mainly addressed through hidden Markov models...
2017: Movement Ecology
https://www.readbyqxmd.com/read/28942318/detection-of-terrigenous-and-marine-organic-matter-flow-into-a-eutrophic-semi-enclosed-bay-by-%C3%AE-13-c-and-%C3%AE-15-n-of-intertidal-macrobenthos-and-basal-food-sources
#14
Iman Arbi, Songlin Liu, Jingping Zhang, Yunchao Wu, Xiaoping Huang
The pathways of terrigenous and marine organic matter originating into Daya Bay intertidal habitats were investigated using carbon and nitrogen stable isotope analyses. Spatiotemporal (sites, seasons and tidal levels) variations in isotopic ratios of basal food sources and macrobenthic consumers, and also the contribution of sources to the diet of representative species and the whole macrobenthic biomass were estimated using Isosource mixing model. Results showed the anthropogenic impacts on benthic and pelagic organic matter as well as macrobenthos, depending on the spatial and temporal scales...
September 20, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28940441/quantitative-analysis-of-the-effect-of-end-tidal-carbon-dioxide-on-regional-cerebral-oxygen-saturation-in-patients-undergoing-carotid-endarterectomy-under-general-anaesthesia
#15
Seung-Hee Ki, Jin-Ho Rhim, Jae-Hong Park, Young-Jin Han, Yong-Pil Cho, Tae-Won Kwon, Byung-Moon Choi, Gyu-Jeong Noh
AIM: Regional cerebral oxygen saturation (rSO2 ) is currently the most used measure in clinical practice to monitor cerebral ischemia in patients undergoing carotid endarterectomy (CEA). Although end-tidal carbon dioxide (PET CO2 ) is known as a factor that influences rSO2 , the relationship between PET CO2 and rSO2 has not been quantitatively evaluated in patients with severe arteriosclerosis. This study aimed to evaluate the effect of PET CO2 on rSO2 in patients undergoing CEA under general anaesthesia...
September 23, 2017: British Journal of Clinical Pharmacology
https://www.readbyqxmd.com/read/28936695/early-application-of-airway-pressure-release-ventilation-may-reduce-the-duration-of-mechanical-ventilation-in-acute-respiratory-distress-syndrome
#16
Yongfang Zhou, Xiaodong Jin, Yinxia Lv, Peng Wang, Yunqing Yang, Guopeng Liang, Bo Wang, Yan Kang
PURPOSE: Experimental animal models of acute respiratory distress syndrome (ARDS) have shown that the updated airway pressure release ventilation (APRV) methodologies may significantly improve oxygenation, maximize lung recruitment, and attenuate lung injury, without circulatory depression. This led us to hypothesize that early application of APRV in patients with ARDS would allow pulmonary function to recover faster and would reduce the duration of mechanical ventilation as compared with low tidal volume lung protective ventilation (LTV)...
September 22, 2017: Intensive Care Medicine
https://www.readbyqxmd.com/read/28931842/restoring-tides-to-reduce-methane-emissions-in-impounded-wetlands-a-new-and-potent-blue-carbon-climate-change-intervention
#17
Kevin D Kroeger, Stephen Crooks, Serena Moseman-Valtierra, Jianwu Tang
Coastal wetlands are sites of rapid carbon (C) sequestration and contain large soil C stocks. Thus, there is increasing interest in those ecosystems as sites for anthropogenic greenhouse gas emission offset projects (sometimes referred to as "Blue Carbon"), through preservation of existing C stocks or creation of new wetlands to increase future sequestration. Here we show that in the globally-widespread occurrence of diked, impounded, drained and tidally-restricted salt marshes, substantial methane (CH4) and CO2 emission reductions can be achieved through restoration of disconnected saline tidal flows...
September 20, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28931660/predicting-epiglottic-collapse-in-patients-with-obstructive-sleep-apnoea
#18
Ali Azarbarzin, Melania Marques, Scott A Sands, Sara Op de Beeck, Pedro R Genta, Luigi Taranto-Montemurro, Camila M de Melo, Ludovico Messineo, Olivier M Vanderveken, David P White, Andrew Wellman
Obstructive sleep apnoea (OSA) is characterised by pharyngeal obstruction occurring at different sites. Endoscopic studies reveal that epiglottic collapse renders patients at higher risk of failed oral appliance therapy or accentuated collapse on continuous positive airway pressure. Diagnosing epiglottic collapse currently requires invasive studies (imaging and endoscopy). As an alternative, we propose that epiglottic collapse can be detected from the distinct airflow patterns it produces during sleep.23 OSA patients underwent natural sleep endoscopy...
September 2017: European Respiratory Journal: Official Journal of the European Society for Clinical Respiratory Physiology
https://www.readbyqxmd.com/read/28927811/postinduction-apnoea-in-dogs-premedicated-with-acepromazine-or-dexmedetomidine-and-anaesthetized-with-alfaxalone-or-propofol
#19
Sarah E Bigby, Thierry Beths, Sébastien Bauquier, Jennifer E Carter
OBJECTIVE: To compare incidence and duration of postinduction apnoea in dogs after premedication with methadone and acepromazine (MA) or methadone and dexmedetomidine (MD) followed by induction with propofol (P) or alfaxalone (A). STUDY DESIGN: Prospective, randomized clinical trial. ANIMALS: A total of 32 American Society of Anesthesiologists class I dogs (15 females, 17 males), aged between 4 months and 4 years, weighing between 3 and 46 kg...
March 2, 2017: Veterinary Anaesthesia and Analgesia
https://www.readbyqxmd.com/read/28925377/applied-upper-airway-resistance-instantly-affects-breath-components-a-unique-insight-into-pulmonary-medicine
#20
Pritam Sukul, Jochen Schubert, Svend Kamysek, Phillip Trefz, Wolfram Miekisch
Respiratory parameters such as flow or rate have complex effects onto exhalation of volatile substances and can hamper clinical interpretation of breath biomarkers. We investigated effects of progressively applied upper-airway resistances onto exhalation of volatile organic compounds (VOCs) in healthy humans. We performed real-time mass-spectrometric determination of breath volatiles in 50 subjects with parallel non-invasive hemodynamic monitoring, breath-resolved spirometry and capnometry during controlled tidal breathing (12 breaths/min)...
September 19, 2017: Journal of Breath Research
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