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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.
Secondly, the pulmonary shunt is caused by zero or low V/Q ratio due to insufficient ventilation and excess perfusion. Improper ventilation lowers blood oxygenation and oxygen supply to body tissues. Although 100% oxygen is inspired, a pulmonary shunt prevents oxygen from being delivered to the alveoli and blood capillaries.
A Peritoneovenous shunt: (also called Denver shunt) [2] is a shunt which drains peritoneal fluid from the peritoneum into veins, usually the internal jugular vein or the superior vena cava. It is sometimes used in patients with refractory ascites. It is a long tube with a non-return valve running subcutaneously from the peritoneum to the ...
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 ...
In cardiology, a cardiac shunt is a pattern of blood flow in the heart that deviates from the normal circuit of the circulatory system. It may be described as right-left , left-right or bidirectional, or as systemic-to-pulmonary or pulmonary-to-systemic .
The zones of the lung divide the lung into four vertical regions, based upon the relationship between the pressure in the alveoli (PA), in the arteries (Pa), in the veins (Pv) and the pulmonary interstitial pressure (Pi):
right heart pressure is higher than left heart pressure and/or the shunt has a one-way valvular opening. Small physiological, or "normal", shunts are seen due to the return of bronchial artery blood and coronary blood through the Thebesian veins, which are deoxygenated, to the left side of the heart.
Physiology [ edit ] The core concept behind fetal circulation is that fetal hemoglobin (HbF) [ 14 ] has a higher affinity for oxygen than does adult hemoglobin , which, together with the difference in partial pressure of oxygen, allows a diffusion of oxygen from the mother's circulatory system to the fetus.