Calculate cardiac output, cardiac index, stroke volume and stroke volume index
The Fick principle, as applied to cardiac output, relies on the recognition that the total uptake of oxygen by the peripheral tissues is equal to the product of the blood flow to the peripheral tissues and the arterial-venous oxygen concentration difference.
Cardiac output is therefore calculated using the formula:
Normal values:
A low CO/CI may be observed with hypovolemia, hypoperfusion, shock, arrhythmia, and severe metabolic acidosis.
A high CO/CI may be observed with hypoxia, the use of positive inotropes, early septic shock and anemia
A low SV/SVI may be observed with impaired LV contractility, acidosis, hypoxemia, hypercapnia, increased afterload, decreased preload and tachycardia
A high SV/SVI may be observed with bradycardia, the use of positive inotropes, and decreases in afterload
Errors with the Fick CO result from a leaky gas collection apparatus, inaccuracies in the measurement of inhaled and exhaled oxygen concentrations (these are particularly common when high levels of oxygen are used), and from errors in the calculations and/or measurements of blood oxygen contents.
Marino P.
Kern MJ.
LaFarge CG, Miettinen OS.
Wilkinson JL.
The Fick principle, as applied to cardiac output, relies on the recognition that the total uptake of oxygen by the peripheral tissues is equal to the product of the blood flow to the peripheral tissues and the arterial-venous oxygen concentration difference.
Cardiac output is therefore calculated using the formula:
Normal values:
A low CO/CI may be observed with hypovolemia, hypoperfusion, shock, arrhythmia, and severe metabolic acidosis.
A high CO/CI may be observed with hypoxia, the use of positive inotropes, early septic shock and anemia
A low SV/SVI may be observed with impaired LV contractility, acidosis, hypoxemia, hypercapnia, increased afterload, decreased preload and tachycardia
A high SV/SVI may be observed with bradycardia, the use of positive inotropes, and decreases in afterload
Errors with the Fick CO result from a leaky gas collection apparatus, inaccuracies in the measurement of inhaled and exhaled oxygen concentrations (these are particularly common when high levels of oxygen are used), and from errors in the calculations and/or measurements of blood oxygen contents.
Marino P.
Kern MJ.
LaFarge CG, Miettinen OS.
Wilkinson JL.
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