Final answer:
To manage a patient's oxygen levels pre and post cardiac arrest with O2 support, maintain SPO2 levels between 95-100 percent using a pulse oximeter. If a pulse oximeter is unavailable in a prehospital setting, administer 100% oxygen until ED arrival. For direct measurements, an ABG can provide the PO2 levels.
Step-by-step explanation:
The goal in managing a patient pre and post cardiac arrest with oxygen support is to maintain normal SPO2 levels, which typically range from 95-100 percent. This is conducted using a pulse oximeter, which provides a non-invasive measure of oxygen saturation. However, if you are in a prehospital setting where a pulse oximeter is not available, the recommendation is to administer 100% oxygen until the patient can be evaluated in the emergency department (ED).
Understanding that the pulse oximeter operates by sending two wavelengths of light (red and infrared) through a part of the body such as the fingertip and then measures the light absorption difference by oxyhemoglobin and deoxyhemoglobin, it provides a percentage known as SPO2. Lower SPO2 percentages indicate hypoxemia. When more direct oxygen level measurements are needed, arterial blood gases (ABG) can be obtained, showing the partial pressure of oxygen (PO2) in units of millimeters of mercury (mm Hg).