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https://www.readbyqxmd.com/read/28427718/improved-linear-quadratic-and-proportional-control-system-for-improved-liquid-level-system-regulation-in-a-coke-fractionation-tower
#1
Jili Tao, Qinru Fan, Longhua Ma
A new linear quadratic regulation (LQ) control plus a proportional (P) control system is proposed for the level regulation in an industrial coke fractionation tower. The process is first stabilized using a P controller and then a subsequent LQ controller is designed for the P control system. The P control system is modeled as a generalized first order plus dead time (FOPDT) process using step-response test and the LQ-P controller is designed through a new state space structure. Performance in terms of regulatory and servo issues were investigated...
April 17, 2017: ISA Transactions
https://www.readbyqxmd.com/read/28413511/application-of-dead-space-fraction-to-titrate-optimal-positive-end-expiratory-pressure-in-an-ards-swine-model
#2
Weishuai Bian, Wei Chen, Yangong Chao, Lan Wang, Liming Li, Jian Guan, Xuefeng Zang, Jie Zhen, Bo Sheng, Xi Zhu
This study aimed to apply the dead space fraction [ratio of dead space to tidal volume (VD/VT)] to titrate the optimal positive end-expiratory pressure (PEEP) in a swine model of acute respiratory distress syndrome (ARDS). Twelve swine models of ARDS were constructed. A lung recruitment maneuver was then conducted and the PEEP was set at 20 cm H2O. The PEEP was reduced by 2 cm H2O every 10 min until 0 cm H2O was reached, and VD/VT was measured after each decrement step. VD/VT was measured using single-breath analysis of CO2, and calculated from arterial CO2 partial pressure (PaCO2) and mixed expired CO2 (PeCO2) using the following formula: VD/VT = (PaCO2 - PeCO2)/PaCO2...
April 2017: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/28372575/implementing-a-bedside-assessment-of-respiratory-mechanics-in-patients-with-acute-respiratory-distress-syndrome
#3
Lu Chen, Guang-Qiang Chen, Kevin Shore, Orest Shklar, Concetta Martins, Brian Devenyi, Paul Lindsay, Heather McPhail, Ashley Lanys, Ibrahim Soliman, Mazin Tuma, Michael Kim, Kerri Porretta, Pamela Greco, Hilary Every, Chris Hayes, Andrew Baker, Jan O Friedrich, Laurent Brochard
BACKGROUND: Despite their potential interest for clinical management, measurements of respiratory mechanics in patients with acute respiratory distress syndrome (ARDS) are seldom performed in routine practice. We introduced a systematic assessment of respiratory mechanics in our clinical practice. After the first year of clinical use, we retrospectively assessed whether these measurements had any influence on clinical management and physiological parameters associated with clinical outcomes by comparing their value before and after performing the test...
April 4, 2017: Critical Care: the Official Journal of the Critical Care Forum
https://www.readbyqxmd.com/read/28351440/-high-nasal-flow-the-solution-for-hypoxaemia
#4
J G van den Aardweg
High nasal flow (HNF) is a new method to deliver a high flow of oxygen (up to 60 l/min) through a nasal cannula. The inspiratory oxygen fraction can be set in a range from 21 to 100%. The inspired air is adjusted to body temperature and saturation. Many patients find it more comfortable than a conventional oxygen mask. In spite of these advantages, the mechanism of action is not completely understood and empirical evidence for its use is limited. This article provides a simplified explanation of variable positive airway pressure generation by HNF and related flushing of the anatomic dead space...
2017: Nederlands Tijdschrift Voor Geneeskunde
https://www.readbyqxmd.com/read/28157805/generalizability-concern-of-alveolar-dead-space-fraction-of-yehya-et-al
#5
Erik Koomen, Roelie M Wösten-van Asperen
No abstract text is available yet for this article.
February 2017: Pediatric Critical Care Medicine
https://www.readbyqxmd.com/read/27886421/pathophysiology-of-dyspnoea-in-acute-pulmonary-embolism-a-cross-sectional-evaluation
#6
Olivier Sanchez, Aurore Caumont-Prim, Elisabeth Riant, Laurent Plantier, Martin Dres, Bruno Louis, Marie-Anne Collignon, Benoit Diebold, Guy Meyer, Claudine Peiffer, Christophe Delclaux
BACKGROUND AND OBJECTIVE: Dyspnoea in pulmonary embolism (PE) remains poorly characterized. Little is known about how to measure intensity or about the underlying mechanisms that may be related to ventilatory abnormalities, alveolar dead space ventilation or modulating factors such as psychological modulate. We hypothesized that dyspnoea would mainly be associated with pulmonary vascular obstruction and its pathophysiological consequences, while the sensory-affective domain of dyspnoea would be influenced by other factors...
November 25, 2016: Respirology: Official Journal of the Asian Pacific Society of Respirology
https://www.readbyqxmd.com/read/27849858/216-pulmonary-dead-space-fraction-and-extubation-success-in-children-after-cardiac-surgery
#7
Renee Devor, Chasity Wellnitz, Paul Kang, Muniza Siddiqui, John Nigro, Daniel Velez, Brigham Willis
No abstract text is available yet for this article.
December 2016: Critical Care Medicine
https://www.readbyqxmd.com/read/27761428/effects-of-flavonoids-from-martynia-annua-and-tephrosia-purpurea-on-cutaneous-wound-healing
#8
Santram Lodhi, Avijeet Jain, Alok Pal Jain, Rajesh Singh Pawar, Abhay Kumar Singhai
OBJECTIVE: Martynia annua L. (M. annua), (Martyniaccae) has been traditionally used in the treatment of epilepsy, sore throat and inflammatory disorders. The leaf paste is used topically on Tuberculosis of the lymphatic glands and wounds of domestic animals. Tephrosia purpurea (T. purpurea), (Fabaceae) has been used traditionally as a remedy for asthma, gonorrhea, rheumatism and ulcers. This study aimed to evaluate the potential wound healing effects of different fractions ofethanol extract of M...
September 2016: Avicenna Journal of Phytomedicine
https://www.readbyqxmd.com/read/27698207/high-flow-nasal-cannula-therapy-for-adult-patients
#9
Jian Zhang, Ling Lin, Konghan Pan, Jiancang Zhou, Xiaoyin Huang
High-flow nasal cannula (HFNC) oxygen therapy has several physiological advantages over traditional oxygen therapy devices, including decreased nasopharyngeal resistance, washing out of the nasopharyngeal dead space, generation of positive pressure in the pharynx, increasing alveolar recruitment in the lungs, humidification of the airways, increased fraction of inspired oxygen and improved mucociliary clearance. Recently, the use of HFNC in treating adult critical illness patients has significantly increased, and it is now being used in many patients with a range of different disease conditions...
December 2016: Journal of International Medical Research
https://www.readbyqxmd.com/read/27688911/can-transcutaneous-co2-tension-be-used-to-calculate-ventilatory-dead-space-a-pilot-study
#10
Pradeep H Lakshminarayana, Adiba A Geeti, Umer M Darr, David A Kaufman
Dead space fraction (V d/V t) measurement performed using volumetric capnography requires arterial blood gas (ABG) sampling to estimate the partial pressure of carbon dioxide (PaCO2). In recent years, transcutaneous capnography (PtcCO2) has emerged as a noninvasive method of estimating PaCO2. We hypothesized that PtcCO2 can be used as a substitute for PaCO2 in the calculation of V d/V t. In this prospective pilot comparison study, 30 consecutive postcardiac surgery mechanically ventilated patients had V d/V t calculated separately using volumetric capnography by substituting PtcCO2 for PaCO2...
2016: Critical Care Research and Practice
https://www.readbyqxmd.com/read/27578482/effects-of-heated-and-humidified-high-flow-gases-during-high-intensity-constant-load-exercise-on-severe-copd-patients-with-ventilatory-limitation
#11
Serena Cirio, Manuela Piran, Michele Vitacca, Giancarlo Piaggi, Piero Ceriana, Matteo Prazzoli, Mara Paneroni, Annalisa Carlucci
INTRODUCTION: High flow nasal cannula (HFNC) was shown to washout the anatomical dead space, permitting a higher fraction of minute ventilation to participate in gas pulmonary exchanges. Moreover, it is able to guarantee the desired inhaled oxygen fraction (FiO2) even at high level of patient's minute ventilation by minimizing the room air entrainment. The effect of HFNC has never been investigated on stable severe COPD patients in term of endurance capacity with standardised laboratory tests...
September 2016: Respiratory Medicine
https://www.readbyqxmd.com/read/27511339/diagnostic-accuracy-of-noninvasive-end-tidal-carbon-dioxide-measurement-in-emergency-department-patients-with-suspected-pulmonary-embolism84-90
#12
Melih Yüksel, Murat Pekdemir, Serkan Yilmaz, Elif Yaka, Aslı Gülfer Kartal
BACKGROUND/AIM: Pulmonary embolism (PE) is a frequent health problem representing a diagnostic challenge with high mortality and morbidity rates. The aim of this study was to investigate the value of end-tidal carbon dioxide (ETCO2) and alveolar dead space fraction (ADSF) in the diagnosis of PE. MATERIALS AND METHODS: ETCO2 levels of patients with suspected PE were measured with a noninvasive mainstream sensor. ADSF of patients was calculated and PaCO2 levels were also obtained...
2016: Turkish Journal of Medical Sciences
https://www.readbyqxmd.com/read/27321293/comparison-of-the-pulmonary-dead-space-fraction-derived-from-ventilator-volumetric-capnography-and-a-validated-equation-in-the-survival-prediction-of-patients-with-acute-respiratory-distress-syndrome
#13
Yu-Jiao Zhang, Xin-Jing Gao, Zhi-Bo Li, Zhi-Yong Wang, Quan-Sheng Feng, Cheng-Fen Yin, Xing Lu, Lei Xu
PURPOSE: This prospective observational study aims to evaluate the accuracy of dead-space fraction derived from the ventilator volumetric capnography (volumetric CO₂) or a prediction equation to predict the survival of mechanically ventilated patients with acute respiratory distress syndrome (ARDS). METHODS: Consecutive VD/VT measurements were obtained based upon a prediction equation validated by Frankenfield et al for dead-space ventilation fraction: VD/VT = 0...
June 1, 2016: Chinese Journal of Traumatology, Zhonghua Chuang Shang za Zhi
https://www.readbyqxmd.com/read/27290006/microcirculatory-alterations-are-associated-with-pulmonary-dead-space-fraction-in-moderate-and-severe-ards
#14
G A Ospina-Tascón, D F Bautista-Rincón, H J Madriñán, J D Valencia, W F Bermúdez, A Bruhn, G Hernández, C E Salas, D De Backer
No abstract text is available yet for this article.
December 2015: Intensive Care Medicine Experimental
https://www.readbyqxmd.com/read/27199318/detection-of-optimal-peep-for-equal-distribution-of-tidal-volume-by-volumetric-capnography-and-electrical-impedance-tomography-during-decreasing-levels-of-peep-in-post-cardiac-surgery-patients
#15
P Blankman, A Shono, B J M Hermans, T Wesselius, D Hasan, D Gommers
BACKGROUND: Homogeneous ventilation is important for prevention of ventilator-induced lung injury. Electrical impedance tomography (EIT) has been used to identify optimal PEEP by detection of homogenous ventilation in non-dependent and dependent lung regions. We aimed to compare the ability of volumetric capnography and EIT in detecting homogenous ventilation between these lung regions. METHODS: Fifteen mechanically-ventilated patients after cardiac surgery were studied...
June 2016: British Journal of Anaesthesia
https://www.readbyqxmd.com/read/27145818/assessment-of-dead-space-ventilation-in-patients-with-acute-respiratory-distress-syndrome-a-prospective-observational-study
#16
Jonne Doorduin, Joeke L Nollet, Manon P A J Vugts, Lisanne H Roesthuis, Ferdi Akankan, Johannes G van der Hoeven, Hieronymus W H van Hees, Leo M A Heunks
BACKGROUND: Physiological dead space (VD/VT) represents the fraction of ventilation not participating in gas exchange. In patients with acute respiratory distress syndrome (ARDS), VD/VT has prognostic value and can be used to guide ventilator settings. However, VD/VT is rarely calculated in clinical practice, because its measurement is perceived as challenging. Recently, a novel technique to calculate partial pressure of carbon dioxide in alveolar air (PACO2) using volumetric capnography (VCap) was validated...
May 5, 2016: Critical Care: the Official Journal of the Critical Care Forum
https://www.readbyqxmd.com/read/26923646/early-prediction-of-extracorporeal-membrane-oxygenation-eligibility-for-severe-acute-respiratory-distress-syndrome-in-adults
#17
J Kyle Bohman, Joseph A Hyder, Vivek Iyer, Sonal R Pannu, Pablo Moreno Franco, Troy G Seelhammer, Louis A Schenck, Gregory J Schears
PURPOSE: Appropriately identifying and triaging patients with newly diagnosed acute respiratory distress syndrome (ARDS) who may progress to severe ARDS is a common clinical challenge without any existing tools for assistance. MATERIALS AND METHODS: Using a retrospective cohort, a simple prediction score was developed to improve early identification of ARDS patients who were likely to progress to severe ARDS within 7 days. A broad array of comorbidities and physiologic variables were collected for the 12-hour period starting from intubation for ARDS...
June 2016: Journal of Critical Care
https://www.readbyqxmd.com/read/26814111/-effect-of-transpulmonary-pressure-directed-mechanical-ventilation-on-respiration-in-severe-acute-pancreatitis-patient-with-intraabdominal-hypertension
#18
Xiaoyan Wu, Ruiqiang Zheng, Hua Lin, Zhiqing Zhuang, Min Zhang, Peixia Yan
OBJECTIVE: To assess the effect of mehanical ventilation (MV) guided by transpulmonary pressure (Ptp) on respiratory mechanics and gas exchange in severe acute pancreatitis patient with intraabdominal hypertension. METHODS: Twelve severe acute pancreatitis patient with intraabdominal hypertension and acute respiratory distress syndrome(ARDS) underwent mechanical ventilation were involved from Jan to Dec 2013. PEEP levels were set to achieve a Ptp of 0 to 10 cm of water at end expiration...
October 20, 2015: Zhonghua Yi Xue za Zhi [Chinese medical journal]
https://www.readbyqxmd.com/read/26673586/a-trial-of-nebulised-heparin-to-limit-lung-injury-following-cardiac-surgery
#19
RANDOMIZED CONTROLLED TRIAL
B Dixon, R Smith, J D Santamaria, N R Orford, B J Wakefield, K Ives, R McKenzie, B Zhang, C H Yap
Cardiac surgery with cardiopulmonary bypass triggers an acute inflammatory response in the lungs. This response gives rise to fibrin deposition in the microvasculature and alveoli of the lungs. Fibrin deposition in the microvasculature increases alveolar dead space, while fibrin deposition in alveoli causes shunting. We investigated whether prophylactic nebulised heparin could limit this form of lung injury. We undertook a single-centre double-blind randomised trial. Forty patients undergoing elective cardiac surgery with cardiopulmonary bypass were randomised to prophylactic nebulised heparin (50,000 U) or placebo...
January 2016: Anaesthesia and Intensive Care
https://www.readbyqxmd.com/read/26549271/review-african-medicinal-plants-with-wound-healing-properties
#20
REVIEW
Christian Agyare, Yaw Duah Boakye, Emelia Oppong Bekoe, Andreas Hensel, Susana Oteng Dapaah, Theresa Appiah
ETHNOPHARMACOLOGICAL RELEVANCE: Wounds of various types including injuries, cuts, pressure, burns, diabetic, gastric and duodenal ulcers continue to have severe socio-economic impact on the cost of health care to patients, family and health care institutions in both developing and developed countries. However, most people in the developing countries, especially Africa, depend on herbal remedies for effective treatment of wounds. Various in vitro and in vivo parameters are used for the evaluation of the functional activity of medicinal plants by using extracts, fractions and isolated compounds...
January 11, 2016: Journal of Ethnopharmacology
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