Oxygen Content - Our Patient

Oxygen content describes the amount of oxygen carried by a specific volume of blood. Almost all oxygen in blood is carried by oxygen binding sites on hemoglobin. The maximum oxygen binding capacity of hemoglobin when 100% saturated is 1.34 cc of oxygen for each gram of hemoglobin. A normal individual with 15 grams of hemoglobin per 100 milliliters of blood, therefore, has an oxygen content of approximately 20 cc per 100 milliliters of blood.

Our patient's oxygen arterial saturation is only 83%, but his hemoglobin is 18 grams per 100 milliliters of blood. If his hemoglobin were 100% saturated, it would contain eighteen times 1.34, or 24 cc of oxygen per 100 milliliters of blood. At 83% saturation, his blood actually contains .83 times 18 times 1.34, or an oxygen content of 20 cc per 100 milliliters of blood. The same as a normal individual with fifteen grams of hemoglobin per 100 milliliters of blood.