A hemoglobin molecule becomes 100% saturated with oxygen (1.34 L of oxygen) at a PO 2 of 100 mmHg.Īfter binding each oxygen molecule, hemoglobin undergoes a conformational change that increases its affinity for the next oxygen molecule. The oxygen content in the blood depends on the oxygen-hemoglobin dissociation curve, which is a plot to define the percentage of saturated hemoglobin to the partial pressure of oxygen (PO 2). A value lower than 90% is considered low oxygen saturation, which requires external oxygen supplementation.ĭuring aerobic metabolism, the body utilizes oxygen to convert glucose into pyruvate and generate two molecules of ATP. This means that a hemoglobin molecule can bind up to four oxygen molecules during transport in the blood.įor adults, the normal range of SaO 2 is 95 – 100%. Oxygen saturation is a vital parameter to define blood oxygen content and oxygen delivery.Įach hemoglobin molecule contains four heme groups that can readily bind molecular oxygen present in the blood. Oxygen saturation measures the percentage of oxyhemoglobin (oxygen-bound hemoglobin) in the blood, and it is represented as arterial oxygen saturation (SaO 2) and venous oxygen saturation (SvO 2). It is an important parameter for managing patients in a clinical setup. Oxygen saturation is a measure of the amount of hemoglobin that is bound to molecular oxygen at a given time point.

Normal pulse ox