EVALUATION OF IMPEDANCE CARDIAC OUTPUT IN CHILDREN

PEDIATRICS ◽  
1971 ◽  
Vol 47 (5) ◽  
pp. 870-879
Author(s):  
Zuhdi Lababidi ◽  
D. A. Ehmke ◽  
Robert E. Durnin ◽  
Paul E. Leaverton ◽  
Ronald M. Lauer
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Standard Deviation ◽  
Pulmonary Blood Flow ◽  
Impedance Measurement ◽  
Aortic Insufficiency ◽  
Mean Difference ◽  
Dye Dilution ◽  
Impedance Cardiograph ◽  
Indicator Dye

In 20 children without shunts or valvular insufficiency, duplicate dye dilution and impedance cardiac outputs (ICO) were carried out. The duplicate dye dilutions had a standard deviation 0.259 L/min/m2, while duplicate ICO had a standard deviation 0.192 L/min/m2 (F = 1.82, p < 0.05). Of 53 sequential estimates, cardiac outputs measured by both indicator dye dilution and ICO had a 5.5% mean difference. In 21 subjects with left to right shunts, the ICO related well with pulmonary blood flow (r = 0.92) rather than systemic flow (r = 0.21). In 13 subjects with aortic insufficiency, sequential Fick and ICO had a 50% mean difference; the impedance measurement was found to be higher in every case. These data indicate that the impedance cardiograph can provide a noninvasive measure of cardiac output when there are no shunts or valvular insufficiencies. In subjects with left to right shunts the impedance cardiograph provides a measure of the pulmonary blood flow. When aortic insufficiency exists the impedance cardiograph is distorted such that it is consistently higher than Fick cardiac output.

Assessment of cardiorespiratory function using oscillating inert gas forcing signals

1994 ◽  
Vol 76 (5) ◽  
pp. 2130-2139 ◽  
Author(s):  
E. M. Williams ◽  
J. B. Aspel ◽  
S. M. Burrough ◽  
W. A. Ryder ◽  
M. C. Sainsbury ◽  
...  
Keyword(s):  
Blood Flow ◽  
Nitrous Oxide ◽  
Dead Space ◽  
Confidence Limit ◽  
Pulmonary Blood Flow ◽  
Mean Difference ◽  
Alveolar Volume ◽  
Single Breath ◽  
Cardiorespiratory Function ◽  
Airway Dead Space

A theoretical model (Hahn et al. J. Appl. Physiol. 75: 1863–1876, 1993) predicts that the amplitudes of the argon and nitrous oxide inspired, end-expired, and mixed expired sinusoids at forcing periods in the range of 2–3 min (frequency 0.3–0.5 min-1) can be used directly to measure airway dead space, lung alveolar volume, and pulmonary blood flow. We tested the ability of this procedure to measure these parameters continuously by feeding monosinusoidal argon and nitrous oxide forcing signals (6 +/- 4% vol/vol) into the inspired airstream of nine anesthetized ventilated dogs. Close agreement was found between single-breath and sinusoid airway dead space measurements (mean difference 15 +/- 6%, 95% confidence limit), N2 washout and sinusoid alveolar volume (mean difference 4 +/- 6%, 95% confidence limit), and thermal dilution and sinusoid pulmonary blood flow (mean difference 12 +/- 11%, 95% confidence limit). The application of 1 kPa positive end-expiratory pressure increased airway dead space by 12% and alveolar volume from 0.8 to 1.1 liters but did not alter pulmonary blood flow, as measured by both the sinusoid and comparator techniques. Our findings show that the noninvasive sinusoid technique can be used to measure cardiorespiratory lung function and allows changes in function to be resolved in 2 min.

Effects of ouabain on cardiac output and pulmonary blood flow in dogs

1972 ◽  
Vol 84 (3) ◽  
pp. 371-376 ◽  
Author(s):  
Elmer Treat ◽  
Harvey Ulano ◽  
Marc Pfeffer ◽  
Walter Massion ◽  
Linda L. Shanbour ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Pulmonary Blood Flow

Single-Breath Breath Holding Measurement of Pulmonary Blood Flow: Comparison to Direct Fick Cardiac Output

1986 ◽  
Vol 71 (s15) ◽  
pp. 36P-36P ◽  
Author(s):  
A.H. Kendrick ◽  
A. Rozkovec ◽  
M. Papouchado ◽  
J. West ◽  
J.E. Bees ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Pulmonary Blood Flow ◽  
Breath Holding ◽  
Single Breath

scholarly journals Spatial-temporal dynamics of pulmonary blood flow in the healthy human lung in response to altered FiO2

2013 ◽  
Vol 114 (1) ◽  
pp. 107-118 ◽  
Author(s):  
Amran K. Asadi ◽  
Matthew V. Cronin ◽  
Rui Carlos Sá ◽  
Rebecca J. Theilmann ◽  
Sebastiaan Holverda ◽  
...  
Keyword(s):  
Blood Flow ◽  
Standard Deviation ◽  
Pulmonary Blood Flow ◽  
Human Lung ◽  
Temporal Dynamics ◽  
Appropriate Technology ◽  
Relative Dispersion ◽  
Mean Flow ◽  
The Mean ◽  
General Response

The temporal dynamics of blood flow in the human lung have been largely unexplored due to the lack of appropriate technology. Using the magnetic resonance imaging method of arterial spin labeling (ASL) with subject-gated breathing, we produced a dynamic series of flow-weighted images in a single sagittal slice of the right lung with a spatial resolution of ∼1 cm3and a temporal resolution of ∼10 s. The mean flow pattern determined from a set of reference images was removed to produce a time series of blood flow fluctuations. The fluctuation dispersion (FD), defined as the spatial standard deviation of each flow fluctuation map, was used to quantify the changes in distribution of flow in six healthy subjects in response to 100 breaths of hypoxia (FiO2= 0.125) or hyperoxia (FiO2= 1.0). Two reference frames were used in calculation, one determined from the initial set of images (FDglobal), and one determined from the mean of each corresponding baseline or challenge period (FDlocal). FDlocalthus represented changes in temporal variability as a result of intervention, whereas FDglobalencompasses both FDlocaland any generalized redistribution of flow associated with switching between two steady-state patterns. Hypoxic challenge resulted in a significant increase (96%, P < 0.001) in FDglobalfrom the normoxic control period and in FDlocal(46%, P = 0.0048), but there was no corresponding increase in spatial relative dispersion (spatial standard deviation of the images divided by the mean; 8%, not significant). There was a smaller increase in FDglobalin response to hyperoxia (47%, P = 0.0015) for the single slice, suggestive of a more general response of the pulmonary circulation to a change from normoxia to hyperoxia. These results clearly demonstrate a temporal change in the sampled distribution of pulmonary blood flow in response to hypoxia, which is not observed when considering only the relative dispersion of the spatial distribution.

Single-breath breath-holding estimate of pulmonary blood flow in man: comparison with direct Fick cardiac output

1989 ◽  
Vol 76 (6) ◽  
pp. 673-676 ◽  
Author(s):  
A. H. Kendrick ◽  
A. Rozkovec ◽  
M. Papouchado ◽  
J. West ◽  
G. Laszlo
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Pulmonary Blood Flow ◽  
Hold Time ◽  
Normal Subjects ◽  
Breath Holding ◽  
Breath Hold ◽  
Single Breath ◽  
Significant Difference ◽  
Cardiac Disorders

1. Resting pulmonary blood flow (Q.), using the uptake of the soluble inert gas Freon-22 and an indirect estimate of lung tissue volume, has been estimated during breath-holding (Q.c) and compared with direct Fick cardiac output (Q.f) in 16 patients with various cardiac disorders. 2. The effect of breath-hold time was investigated by comparing Q.c estimated using 6 and 10 s of breath-holding in 17 patients. Repeatability was assessed by duplicate measurements of Q.c in the patients and in six normal subjects. 3. Q.c tended to overestimate Q.f, the bias and error being 0.09 l/min and 0.59, respectively. The coefficient of repeatability for Q.c in the patients was 0.75 l/min and in the normal subjects was 0.66 1/min. For Q.f it was 0.72 l/min. There was no significant difference in Q.c measured at the two breath-hold times. 4. The technique is simple to perform, and provides a rapid estimate of Q., monitoring acute and chronic changes in cardiac output in normal subjects and patients with cardiac disease.

scholarly journals Validation of capnodynamic determination of cardiac output by measuring effective pulmonary blood flow: a study in anaesthetised children and piglets

2018 ◽  
Vol 121 (3) ◽  
pp. 550-558 ◽  
Author(s):  
J. Karlsson ◽  
P. Winberg ◽  
B. Scarr ◽  
P.A. Lönnqvist ◽  
E. Neovius ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Pulmonary Blood Flow
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