Postoperative volume balance: does stroke volume increase in Trendelenburg's position?

2015 ◽  
Vol 37 (3) ◽  
pp. 314-316 ◽  
Author(s):  
H. Frost ◽  
C. R. Mortensen ◽  
N. H. Secher ◽  
H. B. Nielsen
Keyword(s):  
Stroke Volume ◽  
Volume Increase ◽  
Volume Balance ◽  
Stroke Volume Increase

scholarly journals Does stroke volume increase after a fluid challenge? A study on the management of patients undergoing major head and neck free flap surgery: preliminary data

Critical Care ◽  
2010 ◽  
Vol 14 (Suppl 1) ◽  
pp. P119 ◽  
Author(s):  
L Wijayasiri ◽  
D Garewal ◽  
M Khpal ◽  
A Rhodes ◽  
A Dewhurst ◽  
...  
Keyword(s):  
Stroke Volume ◽  
Head And Neck ◽  
Free Flap ◽  
Preliminary Data ◽  
Fluid Challenge ◽  
Flap Surgery ◽  
Volume Increase ◽  
Free Flap Surgery ◽  
Stroke Volume Increase

Effects of hypergravity on the distributions of lung ventilation and perfusion in sitting humans assessed with a simple two-step maneuver

2004 ◽  
Vol 96 (4) ◽  
pp. 1470-1477 ◽  
Author(s):  
Malin Rohdin ◽  
Patrik Sundblad ◽  
Dag Linnarsson
Keyword(s):  
Stroke Volume ◽  
Large Scale ◽  
Normal Gravity ◽  
Lung Ventilation ◽  
Small Scale ◽  
Volume Increase ◽  
Single Breath ◽  
Ventilation And Perfusion ◽  
Stroke Volume Increase ◽  
Phase Iv

Increased gravity impairs pulmonary distributions of ventilation and perfusion. We sought to develop a method for rapid, simultaneous, and noninvasive assessments of ventilation and perfusion distributions during a short-duration hypergravity exposure. Nine sitting subjects were exposed to one, two, and three times normal gravity (1, 2, and 3 G) in the head-to-feet direction and performed a rebreathing and a single-breath washout maneuver with a gas mixture containing C2H2, O2, and Ar. Expirograms were analyzed for cardiogenic oscillations (COS) and for phase IV amplitude to analyze inhomogeneities in ventilation (Ar) and perfusion [CO2-to-Ar ratio (CO2/Ar)] distribution, respectively. COS were normalized for changes in stroke volume. COS for Ar increased from 1-G control to 128 ± 6% (mean ± SE) at 2 G ( P = 0.02 for 1 vs. 2 G) and 165 ± 13% at 3 G ( P = 0.002 for 2 vs. 3 G). Corresponding values for CO2/Ar were 135 ± 12% ( P = 0.04) and 146 ± 13%. Phase IV amplitude for Ar increased to 193 ± 39% ( P = 0.008) at 2 G and 229 ± 51% at 3 G compared with 1 G. Corresponding values for CO2/Ar were 188 ± 29% ( P = 0.02) and 219 ± 18%. We conclude that not only large-scale ventilation and perfusion inhomogeneities, as reflected by phase IV amplitude, but also smaller-scale inhomogeneities, as reflected by the ratio of COS to stroke volume, increase with hypergravity. Except for small-scale ventilation distribution, most of the impairments observed at 3 G had been attained at 2 G. For some of the parameters and gravity levels, previous comparable data support the present simplified method.

scholarly journals Stroke volume increase to exercise in chronic obstructive pulmonary disease is limited by increased pulmonary artery pressure

Heart ◽  
2008 ◽  
Vol 95 (2) ◽  
pp. 137-141 ◽  
Author(s):  
S Holverda ◽  
H Rietema ◽  
N Westerhof ◽  
J T Marcus ◽  
C T-J Gan ◽  
...  
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Artery ◽  
Stroke Volume ◽  
Pulmonary Disease ◽  
Pulmonary Artery Pressure ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
Volume Increase ◽  
Artery Pressure ◽  
Stroke Volume Increase

scholarly journals Preload Dependency of 2D Right Ventricle Speckle Tracking Echocardiography Parameters in Healthy Volunteers: A Prospective Pilot Study

2021 ◽  
Vol 11 (1) ◽  
pp. 19
Author(s):  
Christophe Beyls ◽  
Yohann Bohbot ◽  
Matthieu Caboche ◽  
Pierre Huette ◽  
Guillaume Haye ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Speckle Tracking ◽  
Longitudinal Strain ◽  
Speckle Tracking Echocardiography ◽  
Systolic Function ◽  
Fluid Challenge ◽  
Volume Increase ◽  
Few Data ◽  
Preload Dependency ◽  
Stroke Volume Increase

(1) Background: Right ventricular (RV) strain parameters derived from the analysis of the tricuspid annular displacement (TAD) are emergent two-dimensional speckle tracking echocardiography (2D-STE) parameter used for the quantitative assessment of RV systolic function. Few data are available regarding 2D-STE parameters and their dependency on RV preload. Our aim was to evaluate the effect of an acute change in RV preload on 2D-STE parameters in healthy volunteers. (2) Methods: Acute modification of RV preload was performed by a fluid challenge (FC): an infusion of 500 mL of 0.9% sodium chloride was given over 5 min in supine position. Preload dependency (responder group) was confirmed by a stroke volume increase of at least 10% measured by echocardiography. (3) Results: Among 32 healthy volunteers, 19 (59%) subjects were classified as non-responders and 13 (41%) as responders. In the responder group, the tricuspid annular plane systolic excursion (TAPSE) significantly increased (20 (20–23.5) mm to 24 (20.5–26.5) mm; p = 0.018), while RV strain parameters significantly decreased after FC: −23.5 ((−22.3)–(−27.3))% to −25 ((−24)–(29.6))%; p = 0.03) for RV free wall longitudinal strain and −22.8 ((−20.4)–(−30.7))% to −23.7 ((−21.2)–(−27))%; p = 0.02) for RV four-chamber longitudinal strain. 2D-STE parameters derived from the TAD analysis were not influenced by the FC (all p > 0.05). (4) Conclusions: In young, healthy volunteers, RV strain parameters and TAPSE are preload dependent, while TAD parameters were not. The loading conditions must be accounted for when evaluating RV systolic function by 2D-STE parameters.

scholarly journals Does Stroke Volume Increase During an Incremental Exercise? A Systematic Review

2016 ◽  
Vol 10 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Stella S. Vieira ◽  
Brunno Lemes ◽  
Paulo de T. C. de Carvalho ◽  
Rafael N. de Lima ◽  
Danilo S. Bocalini ◽  
...  
Keyword(s):  
Heart Rate ◽  
Stroke Volume ◽  
Maximal Exercise ◽  
Body Position ◽  
Left Ventricular ◽  
Volume Data ◽  
Volume Increase ◽  
Exercise Load ◽  
Standardized Reporting ◽  
Contradictory Evidence

Introduction: Cardiac output increases during incremental-load exercise to meet metabolic skeletal muscle demand. This response requires a fast adjustment in heart rate and stroke volume. The heart rate is well known to increase linearly with exercise load; however, data for stroke volume during incremental-load exercise are unclear. Our objectives were to (a) review studies that have investigated stroke volume on incremental load exercise and (b) summarize the findings for stroke volume, primarily at maximal-exercise load. Methods: A comprehensive review of the Cochrane Library’s, Embase, Medline, SportDiscus, PubMed, and Web of Sci-ence databases was carried out for the years 1985 to the present. The search was performed between February and June 2014 to find studies evaluating changes in stroke volume during incremental-load exercise. Controlled and uncontrolled trials were evaluated for a quality score. Results: The stroke volume data in maximal-exercise load are inconsistent. There is evidence to hypothesis that stroke volume increases during maximal-exercise load, but other lines of evidence indicate that stroke volume reaches a plateau under these circumstances, or even decreases. Conclusion: The stroke volume are unclear, include contradictory evidence. Additional studies with standardized reporting for subjects (e.g., age, gender, physical fitness, and body position), exercise test protocols, and left ventricular function are required to clarify the characteristics of stroke volume during incremental maximal-exercise load.

Microstructural and Microchemical Characterization of Nickel Sulfide Inclusions in Plate Glass

1991 ◽  
Vol 49 ◽  
pp. 962-963
Author(s):  
J. Cooper ◽  
O. Popoola ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Glass Matrix ◽  
Nickel Sulfide ◽  
Plate Glass ◽  
Thermal Expansion Mismatch ◽  
Volume Increase ◽  
Β Phase ◽  
Microchemical Characterization

Nickel sulfide inclusions have been implicated in the spontaneous fracture of large windows of tempered plate glass. Two alternative explanations for the fracture-initiating behaviour of these inclusions have been proposed: (1) the volume increase which accompanies the α to β phase transformation in stoichiometric NiS, and (2) the thermal expansion mismatch between the nickel sulfide phases and the glass matrix. The microstructure and microchemistry of the small inclusions (80 to 250 μm spheres), needed to determine the cause of fracture, have not been well characterized hitherto. The aim of this communication is to report a detailed TEM and EDS study of the inclusions.

Strain analysis in composite ceramics

1986 ◽  
Vol 44 ◽  
pp. 494-497
Author(s):  
W. M. Kriven
Keyword(s):  
Strain Field ◽  
Strain Analysis ◽  
Processing Temperature ◽  
Transformation Toughening ◽  
Zirconia Ceramics ◽  
Volume Increase ◽  
Analysis Technique ◽  
Fundamental Understanding ◽  
Contrast Analysis ◽  
Elastic Strain Field

Significant progress towards a fundamental understanding of transformation toughening in composite zirconia ceramics was made possible by the application of a TEM contrast analysis technique for imaging elastic strains. Spherical zirconia particles dispersed in a large-grained alumina matrix were examined by 1 MeV HVEM to simulate bulk conditions. A thermal contraction mismatch arose on cooling from the processing temperature of 1500°C to RT. Tetragonal ZrO2 contracted amisotropically with α(ct) = 16 X 10-6/°C and α(at) = 11 X 10-6/°C and faster than Al2O3 which contracted relatively isotropically at α = 8 X 10-6/°C. A volume increase of +4.9% accompanied the transformation to monoclinic symmetry at room temperature. The elastic strain field surrounding a particle before transformation was 3-dimensionally correlated with the internal crystallographic orientation of the particle and with the strain field after transformation. The aim of this paper is to theoretically and experimentally describe this technique using the ZrO2 as an example and thereby to illustrate the experimental requirements Tor such an analysis in other systems.

Synovial Volume Increase May Flag Worsening OA

2008 ◽  
Vol 7 (2) ◽  
pp. 7
Author(s):  
DAMIAN MCNAMARA
Keyword(s):  
Volume Increase

Validation of the ambulatory measurement of stroke volume by impedance cardiography

1996 ◽  
Author(s):  
Harriette Riese ◽  
Eco de Geus ◽  
Lorenz van Doornen
Keyword(s):  
Stroke Volume ◽  
Impedance Cardiography ◽  
Ambulatory Measurement
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