What information can be provided by the oxyhemoglobin dissociation curve and how can this be utilized in clinical practice?
The oxyhemoglobin dissociation curve provides a graphic representation of the relationship between partial pressure of oxygen (PaO2) and oxygen saturation (SaO2). The relationship is based on affinity or the ability of hemoglobin to hold onto oxygen in the body. The affinity of hemoglobin for oxygen is highest when the PaO2 is 70 mm Hg or higher due to rapid uptake in the pulmonary circulation. Hemoglobin loses it affinity for oxygen in the body as the PaO2 drops below 60 mm Hg in the body due to release of dissolved oxygen as the blood circulates to the peripheral capillary beds. The oxyhemoglobin dissociation curve can be utilized in clinical practice for it is affected by physiological factors occurring the body that cause it to “shift” thereby affecting affinity. A shift to the right leads to decreased affinity and increases the release of oxygen to the tissues and occurs in response to acidosis, hyperthermia, and in the presence of the enzyme 2,3 DPG. A shift to the left leads to
