How to Calculate Estimated O2 Saturation

Oxygen saturation can be figured out with an equation that measures how much oxygen is in the blood stream compared to how much hemoglobin is available. Anything under 92 percent is worrisome, and normally a healthy person will have at least 96 percent. An pulse oximeter is an easy way to find out this percentage. To calculate an approximate saturation value you need arterial oxygen pressure measurements. The arterial oxygen pressure level is typically measured in a lab setting using electrodes that can sense dissolved oxygen in the blood.

Instructions

• 1

  Add 150 to the arterial pressure. When you get the arterial oxygen pressure, there is a math equation to calculate the saturation.

• 2

  Take the starting arterial pressure number and cube it. Take this number and add it to the result of the first number. Divide the number from Step 1 by the result.

• 3

  Take the result of Step 2 and multiply it by 23,400 and add 1 to the answer.

• 4

  Divide the number 1 by the result of Step 3. This is the estimated oxygen saturation level. Convert this to a percent by multiplying by 100.