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Pulse pressure variation

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https://www.readbyqxmd.com/read/29141045/csf-in-the-ventricles-of-the-brain-behaves-as-a-relay-medium-for-arteriovenous-pulse-wave-phase-coupling
#1
William E Butler, Pankaj K Agarwalla, Patrick Codd
The ventricles of the brain remain perhaps the largest anatomic structure in the human body without established primary purpose, even though their existence has been known at least since described by Aristotle. We hypothesize that the ventricles help match a stroke volume of arterial blood that arrives into the rigid cranium with an equivalent volume of ejected venous blood by spatially configuring cerebrospinal fluid (CSF) to act as a low viscosity relay medium for arteriovenous pulse wave (PW) phase coupling...
2017: PloS One
https://www.readbyqxmd.com/read/29136608/variation-of-the-korotkoff-stethoscope-sounds-during-blood-pressure-measurement-analysis-using-a-convolutional-neural-network
#2
Fan Pan, Peiyu He, Chengyu Liu, Taiyong Li, Alan Murray, Dingchang Zheng
Korotkoff sounds are known to change their characteristics during blood pressure (BP) measurement, resulting in some uncertainties for systolic and diastolic pressure (SBP and DBP) determinations. The aim of this study was to assess the variation of Korotkoff sounds during BP measurement by examining all stethoscope sounds associated with each heartbeat from above systole to below diastole during linear cuff deflation. Three repeat BP measurements were taken from 140 healthy subjects (age 21 to 73 years; 62 female and 78 male) by a trained observer, giving 420 measurements...
November 2017: IEEE Journal of Biomedical and Health Informatics
https://www.readbyqxmd.com/read/29123389/alveolar-capillary-reserve-during-exercise-in-patients-with-chronic-obstructive-pulmonary-disease
#3
Mehrdad Behnia, Courtney M Wheatley, Alberto Avolio, Bruce D Johnson
Background: Factors limiting exercise in patients with COPD are complex. With evidence for accelerated pulmonary vascular aging, destruction of alveolar-capillary bed, and hypoxic pulmonary vasoconstriction, the ability to functionally expand surface area during exercise may become a primary limitation. Purpose: To quantify measures of alveolar-capillary recruitment during exercise and the relationship to exercise capacity in a cohort of COPD patients. Methods: Thirty-two subjects gave consent (53% male, with mean ± standard deviation age 66±9 years, smoking 35±29 pack-years, and Global Initiative for Chronic Obstructive Lung Disease (GOLD) classification of 0-4: 2...
2017: International Journal of Chronic Obstructive Pulmonary Disease
https://www.readbyqxmd.com/read/29113716/plethysmography-variability-index-for-prediction-of-fluid-responsiveness-during-graded-haemorrhage-and-transfusion-in-sevoflurane-anaesthetized-mechanically-ventilated-dogs
#4
Yusuke Endo, Koudai Kawase, Taku Miyasho, Tadashi Sano, Kazuto Yamashita, William W Muir
OBJECTIVE: To examine the accuracy of plethysmography variability index (PVI) as a noninvasive indicator of fluid responsiveness in hypovolaemic dogs. STUDY DESIGN: Prospective experimental study. ANIMALS: Six adult healthy sevoflurane-anaesthetized Beagle dogs. METHODS: Dogs were anaesthetized with 1.3-fold their individual minimum alveolar concentration of sevoflurane. The lungs were mechanically ventilated after neuromuscular blockade with vecuronium bromide...
August 25, 2017: Veterinary Anaesthesia and Analgesia
https://www.readbyqxmd.com/read/29095262/diurnal-variation-of-pulse-waveform-parameters-determined-by-laser-speckle-flowgraphy-on-the-optic-nerve-head-in-healthy-subjects
#5
Marie Fukami, Takeshi Iwase, Kentaro Yamamoto, Eimei Ra, Kenta Murotani, Hiroko Terasaki
To investigate the diurnal variation of the pulse waveform parameters determined by laser speckle flowgraphy (LSFG) on the optic nerve head (ONH) in healthy subjects.This prospective cross sectional study was conducted at Nagoya University Hospital. We studied 13 healthy volunteers whose mean age was 33.5 ± 7.6 years. Eight pulse waveform parameters on the ONH were determined by LSFG (LSFG-NAVI) every 3 hours from 6 AM to 12 PM. The intraocular pressure (IOP), systolic (SBP) and diastolic (DBP) blood pressure, and heart rate (HR) in the brachial artery were also recorded...
November 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/29064375/on-algorithms-for-calculating-arterial-pulse-pressure-variation-during-major-surgery
#6
Shaoxiong Sun, Wouter Peeters, Rick Bezemer, Xi Long, Igor Paulussen, Ronald M Aarts, Gerrit Jan Noordergraaf
Arterial pulse pressure variation (PPV) is widely used for predicting fluid responsiveness and supporting fluid management in the operating room and intensive care unit. Available PPV algorithms have been typically validated for fluid responsiveness during episodes of hemodynamic stability. Yet, little is known about the performance of PPV algorithms during surgery, where fast changes of the blood pressure may affect the robustness of the presented PPV value. This work provides a comprehensive understanding of how various existing algorithmic designs affect the robustness of the presented PPV value during surgery, and proposes additional processing for the pulse pressure signal before calculating PPV...
October 24, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/29060346/coherence-analysis-of-invasive-blood-pressure-and-its-noninvasive-indicators-for-improvement-of-cuffless-measurement-accuracy
#7
Xiao-Rong Ding, Bryan P Yan, Yuan-Ting Zhang, Jing Liu, Peng Su, Ni Zhao
Cuffless technology for blood pressure (BP) measurement offers great potential for unobtrusive monitoring of hypertension. However, the accuracy is still a challenging issue probably owning to the inadequacy of existing noninvasive BP indicators in tracking BP changes, i.e., either the poor trackability of the indicators or the lack of relationship to map the indicators to BP. To figure out the covariation of BP-related noninvasive indicators and BP, we propose to analyze the coherence of intra-arterial systolic BP (SBP) and a selected group of noninvasive indicators, including the mostly used pulse transit time (PTT), photoplethysmogram intensity ratio (PIR) and RR interval (RRI) of electrocardiogram (ECG), in both time domain, with singular spectrum analysis (SSA), and frequency domain, with cross-spectral analysis...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/29060318/a-novel-blood-pressure-estimation-method-combing-pulse-wave-transit-time-model-and-neural-network-model
#8
Jun Xu, Jiehui Jiang, Hucheng Zhou, Zhuangzhi Yan
Blood Pressure (BP) measurement can assist doctors to assess patients' cardiovascular status and diagnose heart diseases. Pulse Wave Transit Time (PWTT) model is one frequently used BP estimation method to monitor BP continuously in clinics. However, individual variations may influence the measurement accuracy of PWTT model. Focusing on above promble, this paper proposes a novel BP estimation method combining a classical PWTT model and a neural network model. The novel method is composed of five steps: signal pre-processing, feature extraction, initial PWTT model selection, model correction by neural network model, and final PWTT model identification...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/29060213/measurement-of-carotid-blood-pressure-and-local-pulse-wave-velocity-changes-during-cuff-induced-hyperemia
#9
P M Nabeel, Srinivasa Karthik, Jayaraj Joseph, Mohanasankar Sivaprakasam
We present a prototype design of dual element photoplethysmograph (PPG) probe along with associated measurement system for carotid local pulse wave velocity (PWV) evaluation in a non-invasive and continuous manner. The PPG probe consists of two identical sensing modules placed 23 mm apart. Simultaneously measured blood pulse waveforms from these arterial sites were processed and the pulse transit time delay was resolved using the developed application-specific software. The ability of developed PPG probe and associated measurement system to detect acute changes in carotid local PWV due to blood pressure (BP) variations was experimentally validated by an in-vivo study...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/29059329/short-term-repeatability-of-noninvasive-aortic-pulse-wave-velocity-assessment-comparison-between-methods-and-devices
#10
Andrea Grillo, Gianfranco Parati, Matteo Rovina, Francesco Moretti, Lucia Salvi, Lan Gao, Corrado Baldi, Giovanni Sorropago, Andrea Faini, Sandrine C Millasseau, Filippo Scalise, Renzo Carretta, Paolo Salvi
BACKGROUND: Aortic pulse wave velocity (PWV) is an indirect index of arterial stiffness and an independent cardiovascular risk factor. Consistency of PWV assessment over time is thus an essential feature for its clinical application. However, studies providing a comparative estimate of the reproducibility of PWV across different noninvasive devices are lacking, especially in the elderly and in individuals at high cardiovascular risk. METHODS: Aimed at filling this gap, short-term repeatability of PWV, estimated with 6 different devices (Complior Analyse, PulsePen-ETT, PulsePen-ET, SphygmoCor Px/Vx, BPLab, and Mobil-O-Graph), was evaluated in 102 high cardiovascular risk patients hospitalized for suspected coronary artery disease (72 males, 65 ± 13 years)...
October 20, 2017: American Journal of Hypertension
https://www.readbyqxmd.com/read/29058686/single-source-ppg-based-local-pulse-wave-velocity-measurement-a-potential-cuffless-blood-pressure-estimation-technique
#11
Nabeel P M, Jayaraj Joseph, Mohanasankar Sivaprakasam
<i>Objective:</i> A novel photoplethysmograph (PPG) probe employs dual photodiodes excited using single infrared light source was developed for local Pulse Wave Velocity (PWV) measurement. The potential use of proposed system in cuffless Blood Pressure (BP) techniques was demonstrated. <i>Approach:</i> Initial validation measurements were performed on a phantom using a reference method. Further, an in-vivo study was carried out in 35 volunteers (age = 28 ± 4.5 years). Carotid local PWV, carotid to finger Pulse Transit Time (PTT<sub>R</sub>) and Pulse Arrival Time at the carotid artery (PAT<sub>C</sub>) were simultaneously measured...
October 23, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/29051112/in-vivo-and-in-silico-evaluation-of-a-new-nitric-oxide-donor-s-s-dinitrosobucillamine
#12
Marie-Lynda Bouressam, Benjamin Meyer, Ariane Boudier, Igor Clarot, Pierre Leroy, Alessandro Genoni, Manuel Ruiz-Lopez, Philippe Giummelly, Patrick Liminana, Valérie Salgues, Mostafa Kouach, Caroline Perrin-Sarrado, Isabelle Lartaud, François Dupuis
PURPOSE: In a previous work, we have synthetized a new dinitrosothiol, i.e. S,S'-dinitrosobucillamine BUC(NO)2 combining S-nitroso-N-acetylpenicillamine (SNAP) and S-nitroso-N-acetylcysteine (NACNO) in its structure. When exposed to isolated aorta, we observed a 1.5-fold increase of (•)NO content and a more potent vasorelaxation (1 log higher pD2) compared to NACNO and SNAP alone or combined (Dahboul et al., 2014). In the present study, we analyzed the thermodynamics and kinetics for the release of (•)NO through computational modeling techniques and correlated it to plasma assays...
October 16, 2017: Nitric Oxide: Biology and Chemistry
https://www.readbyqxmd.com/read/29043840/comparison-of-two-methods-based-on-photoplethysmography-for-the-diagnosis-of-peripheral-arterial-disease
#13
Christian Høyer, Nikolaj Schandorph Nielsen, Malene Kragh Overvad Jordansen, Helle Damgaard Zacho
AIM: To examine the interchangeability of two methods for distal pressure measurement based on photoplethysmography using a truncated or full display of the arterial inflow curve, respectively. METHODS: Toe and ankle pressures were obtained from 69 patients suspected of peripheral arterial disease (PAD). Observer reproducibility of the curve readings was examined by blinded reassessment of the pressure curves in a randomly selected subgroup (60 limbs). RESULTS: There were no significant differences in mean pressures between the two methods (p for all > ...
October 18, 2017: Scandinavian Journal of Clinical and Laboratory Investigation
https://www.readbyqxmd.com/read/29030937/changes-in-blood-volume-indicators-and-dynamic-indicators-measured-with-transpulmonary-ultrasound-velocity-during-blood-depletion-and-repletion-in-a-neonatal-swine-model
#14
Manuel Martin-Flores, Alvaro F Cisternas, Robin D Gleed
BACKGROUND: Dynamic indicators such as pulse pressure and stroke volume variations can be measured to track changes in preload during hemorrhage, and evaluate fluid therapy. However, these dynamic indicators require mechanical ventilation, and might be affected by cardiac dysrhythmias and changes in vascular tone. Blood volume indicators may offer alternatives for assessing changes in volume status. AIMS: The aims of this study were to measure changes in blood volume indicators and dynamic indicators during removal of blood in two stages and subsequent blood replacement in anesthetized, mechanically ventilated, neonatal pigs...
November 2017: Paediatric Anaesthesia
https://www.readbyqxmd.com/read/29030403/new-blood-pressure-associated-loci-identified-in-meta-analyses-of-475%C3%A2-000-individuals
#15
Aldi T Kraja, James P Cook, Helen R Warren, Praveen Surendran, Chunyu Liu, Evangelos Evangelou, Alisa K Manning, Niels Grarup, Fotios Drenos, Xueling Sim, Albert Vernon Smith, Najaf Amin, Alexandra I F Blakemore, Jette Bork-Jensen, Ivan Brandslund, Aliki-Eleni Farmaki, Cristiano Fava, Teresa Ferreira, Karl-Heinz Herzig, Ayush Giri, Franco Giulianini, Megan L Grove, Xiuqing Guo, Sarah E Harris, Christian T Have, Aki S Havulinna, He Zhang, Marit E Jørgensen, AnneMari Käräjämäki, Charles Kooperberg, Allan Linneberg, Louis Little, Yongmei Liu, Lori L Bonnycastle, Yingchang Lu, Reedik Mägi, Anubha Mahajan, Giovanni Malerba, Riccardo E Marioni, Hao Mei, Cristina Menni, Alanna C Morrison, Sandosh Padmanabhan, Walter Palmas, Alaitz Poveda, Rainer Rauramaa, Nigel William Rayner, Muhammad Riaz, Ken Rice, Melissa A Richard, Jennifer A Smith, Lorraine Southam, Alena Stančáková, Kathleen E Stirrups, Vinicius Tragante, Tiinamaija Tuomi, Ioanna Tzoulaki, Tibor V Varga, Stefan Weiss, Andrianos M Yiorkas, Robin Young, Weihua Zhang, Michael R Barnes, Claudia P Cabrera, He Gao, Michael Boehnke, Eric Boerwinkle, John C Chambers, John M Connell, Cramer K Christensen, Rudolf A de Boer, Ian J Deary, George Dedoussis, Panos Deloukas, Anna F Dominiczak, Marcus Dörr, Roby Joehanes, Todd L Edwards, Tõnu Esko, Myriam Fornage, Nora Franceschini, Paul W Franks, Giovanni Gambaro, Leif Groop, Göran Hallmans, Torben Hansen, Caroline Hayward, Oksa Heikki, Erik Ingelsson, Jaakko Tuomilehto, Marjo-Riitta Jarvelin, Sharon L R Kardia, Fredrik Karpe, Jaspal S Kooner, Timo A Lakka, Claudia Langenberg, Lars Lind, Ruth J F Loos, Markku Laakso, Mark I McCarthy, Olle Melander, Karen L Mohlke, Andrew P Morris, Colin N A Palmer, Oluf Pedersen, Ozren Polasek, Neil R Poulter, Michael A Province, Bruce M Psaty, Paul M Ridker, Jerome I Rotter, Igor Rudan, Veikko Salomaa, Nilesh J Samani, Peter J Sever, Tea Skaaby, Jeanette M Stafford, John M Starr, Pim van der Harst, Peter van der Meer, Cornelia M van Duijn, Anne-Claire Vergnaud, Vilmundur Gudnason, Nicholas J Wareham, James G Wilson, Cristen J Willer, Daniel R Witte, Eleftheria Zeggini, Danish Saleheen, Adam S Butterworth, John Danesh, Folkert W Asselbergs, Louise V Wain, Georg B Ehret, Daniel I Chasman, Mark J Caulfield, Paul Elliott, Cecilia M Lindgren, Daniel Levy, Christopher Newton-Cheh, Patricia B Munroe, Joanna M M Howson
BACKGROUND: Genome-wide association studies have recently identified >400 loci that harbor DNA sequence variants that influence blood pressure (BP). Our earlier studies identified and validated 56 single nucleotide variants (SNVs) associated with BP from meta-analyses of exome chip genotype data. An additional 100 variants yielded suggestive evidence of association. METHODS AND RESULTS: Here, we augment the sample with 140 886 European individuals from the UK Biobank, in whom 77 of the 100 suggestive SNVs were available for association analysis with systolic BP or diastolic BP or pulse pressure...
October 2017: Circulation. Cardiovascular Genetics
https://www.readbyqxmd.com/read/28984705/the-crashing-patient-hemodynamic-collapse
#16
Hitesh Gidwani, Hernando Gómez
PURPOSE OF REVIEW: Rapid restoration of tissue perfusion and oxygenation are the main goals in the resuscitation of a patient with circulatory collapse. This review will focus on providing an evidence based framework of the technological and conceptual advances in the evaluation and management of the patient with cardiovascular collapse. RECENT FINDINGS: The initial approach to the patient in cardiovascular collapse continues to be based on the Ventilate-Infuse-Pump rule...
December 2017: Current Opinion in Critical Care
https://www.readbyqxmd.com/read/28981568/assessment-of-dynamic-variables-of-fluid-responsiveness-to-predict-desufflation-induced-hypotension-during-paediatric-laparoscopic-surgery
#17
E-H Kim, J-H Lee, I-K Song, H-G Ryu, H-S Kim, J-T Kim
Background: During laparoscopic surgery in paediatric patients, sudden hypotension may occur following peritoneal desufflation due to hypovolaemia or an acute increase in gastrointestinal venous capacitance by the release of intra-abdominal pressure. This study examined whether dynamic variables of fluid responsiveness during pneumoperitoneum can predict the occurrence of hypotension following desufflation. Methods: A total of 120 paediatric subjects were prospectively enrolled...
November 1, 2017: British Journal of Anaesthesia
https://www.readbyqxmd.com/read/28974059/predictor-of-fluid-responsiveness-in-the-grey-zone-augmented-pulse-pressure-variation-through-a-temporary-increase-in-tidal-volume
#18
J J Min, N-S Gil, J-H Lee, D K Ryu, C S Kim, S M Lee
Background: Pulse pressure variation (PPV) is widely used as a predictor of fluid responsiveness. However, a previous study has suggested a 'grey zone' between 9 and 13% in which PPV would be inconclusive to predict fluid responsiveness. Considering PPV is based on cardiopulmonary interactions, we evaluated whether an augmented PPV using a temporary increase in tidal volume (V T ) from 8 to 12 ml kg -1 has the predictability for fluid responsiveness in patients within the grey zone...
July 1, 2017: British Journal of Anaesthesia
https://www.readbyqxmd.com/read/28971030/data-availability-and-feasibility-of-various-techniques-to-predict-response-to-volume-expansion-in-critically-ill-patients
#19
Michael J Lanspa, Benjamin J Briggs, Eliotte L Hirshberg, Cristina M Pratt, Colin K Grissom, Samuel M Brown
OBJECTIVE: The accuracy of various techniques to predict response to volume expansion in shock has been studied, but less well known is how feasible these techniques are in the ICU. METHODS: This is a prospective observation single-center study of inpatients from a mixed profile ICU who received volume expansion. At time of volume expansion, we determined whether a particular technique to predict response was feasible, according to rules developed from available literature and nurse assessment...
July 2017: International Journal of Critical Illness and Injury Science
https://www.readbyqxmd.com/read/28957328/exploiting-ecology-in-drug-pulse-sequences-in-favour-of-population-reduction
#20
Marianne Bauer, Isabella R Graf, Vudtiwat Ngampruetikorn, Greg J Stephens, Erwin Frey
A deterministic population dynamics model involving birth and death for a two-species system, comprising a wild-type and more resistant species competing via logistic growth, is subjected to two distinct stress environments designed to mimic those that would typically be induced by temporal variation in the concentration of a drug (antibiotic or chemotherapeutic) as it permeates through the population and is progressively degraded. Different treatment regimes, involving single or periodical doses, are evaluated in terms of the minimal population size (a measure of the extinction probability), and the population composition (a measure of the selection pressure for resistance or tolerance during the treatment)...
September 2017: PLoS Computational Biology
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