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The Shunt equation (also known as the Berggren equation) quantifies the extent to which venous blood bypasses oxygenation in the capillaries of the lung.. “Shunt” and “dead space“ are terms used to describe conditions where either blood flow or ventilation do not interact with each other in the lung, as they should for efficient gas exchange to take place.
where is the pulmonary vein, is the pulmonary artery, is the systemic arterial, and is the mixed-venous The Qp:Qs ratio is based upon the Fick principle and it is reduced to the above equation and eliminates the need to know cardiac output and hemoglobin concentration.
Utilizing the Fick principle, the ratio of blood flow in the lungs (Qp) and system circulations (Qs) can calculate the Qp:Qs ratio. Elevation of the Qp:Qs ratio above 1.5 to 2.0 suggests that there is a hemodynamically significant left-to-right shunt (such that the blood flow through the lungs is 1.5 to 2.0 times more than the systemic ...
The Q factor is a parameter that describes the resonance behavior of an underdamped harmonic oscillator (resonator). Sinusoidally driven resonators having higher Q factors resonate with greater amplitudes (at the resonant frequency) but have a smaller range of frequencies around that frequency for which they resonate; the range of frequencies for which the oscillator resonates is called the ...
A right-to-left shunt occurs when: there is an opening or passage between the atria, ventricles, and/or great vessels; and,; right heart pressure is higher than left heart pressure and/or the shunt has a one-way valvular opening.
Surgical correction should be considered in the presence of significant left to right shunting (Qp:Qs ≥ 2:1) and pulmonary hypertension. This involves creation of an inter-atrial baffle to redirect the pulmonary venous return into the left atrium. Alternatively, the anomalous vein can be re-implanted directly into the left atrium. [citation ...
If one were to consider humidified air (with less oxygen), then the ideal v/q ratio would be in the vicinity of 1.0, thus leading to concept of ventilation-perfusion equality or ventilation-perfusion matching. This matching may be assessed in the lung as a whole, or in individual or in sub-groups of gas-exchanging units in the lung.
The Q-function can be generalized to higher dimensions: [14] = (),where (,) follows the multivariate normal distribution with covariance and the threshold is of the form = for some positive vector > and positive constant >.