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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.
The saturation of mixed venous blood is approximately 75% in health. Using this value in the above equation, the oxygen concentration of mixed venous blood is approximately 150 mL of O 2 per L. Therefore, using the assumed Fick determination, the approximated cardiac output for an average man (1.9 m3) is:
A pulmonary shunt is the passage of deoxygenated blood from the right side of the heart to the left without participation in gas exchange in the pulmonary capillaries. It is a pathological condition that results when the alveoli of parts of the lungs are perfused with blood as normal, but ventilation (the supply of air) fails to supply the perfused region.
The alveolar air equation is not widely used in clinical medicine, probably because of the complicated appearance of its classic forms. The partial pressure of oxygen ( p O 2 ) in the pulmonary alveoli is required to calculate both the alveolar-arterial gradient of oxygen and the amount of right-to-left cardiac shunt , which are both clinically ...
The Blalock–Thomas–Taussig shunt (BTT shunt), [1] previously known as the Blalock–Taussig Shunt (BT shunt), [2] is a surgical procedure used to increase blood flow to the lungs in some forms of congenital heart disease [3] such as pulmonary atresia and tetralogy of Fallot, which are common causes of blue baby syndrome. [3]
This must be balanced with adequate oxygenation and systemic delivery of oxygenated blood. This modified circulatory system is established by detaching the superior vena cava from the right atrium and connecting the cranial part of the SVC to the pulmonary arteries (shunt). This is an example of a surgical anastomosis. As a result, the venous ...
The Bohr equation helps us find the amount of any expired gas, CO 2, N 2, O 2, etc. In this case we will focus on CO 2. Defining F e as the fraction of CO 2 in the average expired breath, F A as the fraction of CO 2 in the perfused alveolar volume, and F d as the CO 2 makeup of the unperfused (and thus 'dead') region of the lung; V T x F e ...
The FEV1/FVC ratio, also called modified Tiffeneau-Pinelli index, [1] is a calculated ratio used in the diagnosis of obstructive and restrictive lung disease. [ 2 ] [ 3 ] It represents the proportion of a person's vital capacity that they are able to expire in the first second of forced expiration ( FEV1 ) to the full, forced vital capacity ...