<prompt> If a patient has an oxygen consumption of 240 mlmin, a pulmonary vein oxygen concentration of 180 mlL of blood, and a pulmonary aery oxygen concentration of 160 mlL of blood units, what is the cardiac output in Lmin?8101214  <response>: CO 240 180-160 12 Lmin To determine cardiac output by direct Ficks 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: 