If a patient has an oxygen consumption of 240 ml/min, a pulmonary vein oxygen concentration of 180 ml/L of blood, and a pulmonary aery oxygen concentration of 160 ml/L of blood units, what is the cardiac output in L/min?
CO= 240 / (180-160) = 12 L/min To determine cardiac output by direct Fick's method, three values must be known: 1. O2 consumption of the body (measured by the rate of disappearance of oxygen from the respired air, using any type of oxygen meter) 2. O2 concentration in venous blood (a catheter inseed up the brachial vein of the forearma the subclan vein - right atrium - right ventricle or pulmonary aery) 3. O2 concentration in aerial blood (can then be obtained from any systemic aery in the body) Other methods of CO measurement: 1. Echocardiography 2. Indicator dilution method a. Dye dilution b. Thermodilution: Cold saline is used as the indicator which is injected into right atrium Indicator dilution method:
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Cardiovascular System