The Advantages of Pulse Oximetry

Until fairly recently, the only way to check a patient’s arterial oxygen level was by taking blood from an artery for analysis, which is time consuming and potentially dangerous. This procedure is still used and essential in emergency, critical and even acute care when a patient is in distress. However, the safest, quickest and least invasive means by which to determine a patient’s oxygen saturation is with a pulse oximeter.

Speed

• Pulse oximetry measures a patient’s arterial saturation of oxygen (SaO2) in seconds; measurements obtained from arterial blood gases (ABG) can take several minutes to acquire and are usually drawn by a respiratory therapist, transported to the blood gas lab, measured and finally reported back to the doctor. The information from an ABG analysis provides for more information than just the oxygen level and is essential in emergencies, but oximetry is equally important to ensure the patient does not suffer the effects of hypoxia unnecessarily.

Accurate and Easy to Use

• While not as precise as an ABG measurement, pulse oximeters are accurate with most patients, especially in emergency situations where seconds matter; however, it should not be used indiscriminately for some chronic conditions, such as chronic obstructive pulmonary disease (COPD), in which a patient may have chronically low oxygen levels and raising them too high can be dangerous. Little to no training is needed to perform pulse oximetry. Most oximeters have only one button and as long as the probe is placed properly, virtually anyone can use it. In their infancy, oximeters were the size of old cassette recorders and just as cumbersome. The newest generation of oximeters is streamlined, rugged and even easier to use. Furthermore, they are now available for home use.

Non-Invasive and Reliable

• ABG measurements, though exact, require blood drawn from an artery, which can lead to complications ranging from hematoma to laceration of the artery. Pulse oximetry is performed on a fingertip and measures through the nail bed. As long as the oximeter is used properly and is calibrated regularly, it is easy to use and usually reliable. Good peripheral circulation in the patient’s extremities is critical to obtaining accurate readings and most oximeters on the market incorporate a perfusion gauge, usually in LED bar lights, that shows the strength of the patient’s peripheral circulation. When a strong pulse is not present in the hands or feet, readings can be made with a special adhesive probe placed on the patient’s earlobe or even the bridge of the nose.