Sao2 refers to the saturation of oxygen, which is found in the blood arteries. According to Ahrens, Basham, and Rutherford (1993), oxygen saturation (saO2) can vary depending on oxygen levels. If there is high oxygen abundance in the pulmonary capillaries, it leads to the intertwining/binding of oxygen and hemoglobin, leading to an oxygen saturation of over 90 percent, which is considered normal. According to Williams and Wilkins (2009), normal oxyhemoglobin saturation levels are 95 to 100 percent for adults. Conversely, if there is a low oxygen level at the capillaries, there will be a release of oxygen from hemoglobin, resulting in a saturation level of 60 to 75 percent.  Hemoglobin is a compound that enables 98 percent oxygen to be transported through the blood to the body. One molecule of hemoglobin can carry four molecules of oxygen. From there onwards, hemoglobin increases its susceptibility to uptake the next oxygen molecule. Other than hemoglobin, oxygen can be transported in the body via dissolution. Oxygen saturation is also an indicator of the oxygen that is available to the end organs

Hemoglobin

The amount of hemoglobin oxygen saturation can be studied by studying the color of hemoglobin molecules. A bright red Haemoglobin molecule has oxygen, while a dull red hemoglobin molecule is dull in color. According to Medical News Today, if there is a low level of oxygen, 60 millimeters of mercury, there is a need to increase the oxygen level. When a person cannot produce the average level of oxygen in the blood, it leads to a condition known as hypoxemia, whose symptoms include shortness of breath, as is the case of pneumonia and Covid-19, headaches, and confusion. Oxygen saturation may be important in detecting the problems of delivering oxygen to the tissue. According to Websters (1997), these problems exist when there is a blocked airway, as is the case of asthma, poor circulation of air in and out of the lungs, or an improper mixture of gases. Without oxygen for some amount of time, cells will die. If there are low oxygen saturation levels, there is a need for supplemental oxygen after consulting a physician, notes News Medical. The physician may recommend that one way to boost the oxygen saturation levels is through day-to-day body exercises, as they can improve the lung’s capacity to exchange gases such as oxygen and carbon dioxide. According to Nolan, Drisko, and Wagner (2020), well-trained athletes have high hemoglobin levels to transport oxygen to the muscle cells. Furthermore, the physician can also recommend eating a balanced diet; eating foods rich in iron can be important to transport nutrients and oxygen to the blood. Other foods such as Vitamins E and K2 help transport oxygen to the blood cells and increase the oxygen-carrying capacity of hemoglobin in the red blood cells. Magnesium and calcium assist in the transportation of oxygen to the cell. 

Measurement of Oxygen Saturation

According to Ahrens, Basham, and Rutherford (1993), oxygen saturation measured dates back to 1934, when the oximeter was first introduced, which was later improvised to the pulse oximetry in the early 1970s. Here, the pulsation of arterial blood identified by infrared light absorption allowed for the isolation of an oxygen saturation specific to arterial blood. A pulse oximeter measures the percentage of hemoglobin saturation, 98 percent to 100 percent, notes the American Academy of Orthopedic Surgeons. The limitation of a pulse oximeter is that it cannot distinguish when it has measured oxygen saturation different from carbon monoxide saturation, as its work is to measure hemoglobin saturation.  In this age, computer technology has allowed for the processing of quicker and accurate arterial oxygen saturation. Oxygen saturation can also be measured with an arterial blood gas  (ABG), where blood is withdrawn from the arteries.