How Do I Calculate Oxygen Delivery?
- 1). Determine the amount of blood pumped, or the stroke volume in every beat, and the heart rate.
- 2). Find the cardiac output, which measures the volume of blood pumped by the heart per minute. Multiply stroke volume times beats per minute. If a patient has a stroke volume of 65 milliliters and a heart rate of 70 beats per minute, the equation would be 65 milliliters times 70 beats per minute totaling 4,550 milliliters per minute. Divide the answer by 1,000 to convert it to liters. The cardiac output is 4.5 liters per minute.
- 3). Indicate the number of grams of hemoglobin the patient is using per liter of blood. Hemoglobin can be measured using red blood cells. The red blood cells are lysed, releasing hemoglobin. The concentration is then calculated using light absorption. The normal range for an adult is 150g per liter.
- 4). Indicate the proportion of the hemoglobin that is saturated or carrying oxygen. Saturation is usually between 97 and 100 percent for an adult.
- 5). Multiply the cardiac output (liters/minute) times the hemoglobin (Hg) concentration (grams/liter) times 1.31 (milliliters O2/grams Hb) times the percent saturation. Input the following into the equation: 4.5 liters per minute times 150g per liter times 1.3 milliliters per oxygen per gram times 98 divided by 100. Your answer should be 859.95 milliliters per minute.
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