Some Facts About Pulse Oximetry

Pulse oximetry detects some medical issues but not all of it; it is useful in identifying patients with hypoxia but cannot identify patients with hypercarbia; most emergency medical doctors often rely on pulse oximetry as it is known as the fifth vital sign. Arterial oxygen and fractional saturation can be approximated with a Pulse Oximeter, which is an indirect, noninvasive technique; saturation percentage of hemoglobin are measured by oximetery and device such as pulse oximeter. Pulse oximeter is a probe with a light-emitting diode connected by cable to an oximeter; oxygenated and deoxygenated hemoglobin molecules reflects whatever light waves emitted by the LED, in which the oximeter calculates pulse oxygen saturation coming from the reflected light from LED. Mechanics of pulse oximetry can be explained in a way like a probe that is placed over a pulsating arterial bed such as finger and earlobe; there will be two LED lights that transmit red and infrared light through the body tissue to a photo detector on the other side of the probe.

Pulse oximetry records the percentage of hemoglobin that has been fully saturated with oxygen; the light that has been transmitted is absorbed by tissues and reports the results at the other end of the probe; the light is an important aspect, as the oxygen present in hemoglobin will give a difference in light absorption and it must be tested in a number of pulses. Portability is one of the main features of pulse oximeter nowadays, just a decade ago they were just used in special areas like intensive care units and operating rooms; it really gained popularity and it is crucial for hospital operation that is why it is more available today.

When invasive and non-invasive ventilation is transpiring, observing of pulse oximetry must be highly regarded; there are also instances like patient’s recovery and when patients are in general anesthesia. General types of pulse oximeters that are in modern use are transmission pulse oximeters and reflectance pulse oximeters; transmission pulse oximeters are widely and commonly use, it entails a pair of light emitting diodes with a photo detector placed on opposite sides of the interposed tissues, normally a finger or earlobe; sometimes foot and nose bridge are occasionally used.

The not so popular pulse oximetry is reflectance Pulse Oximeter; it involves a method in which photo waves from LEDs are bounced off in an appropriate surface, the reflected light then passes through the tissue like the forehead to reach the photo detector adjoining to the LEDs.

There are studies showing that there are significant decreases in mortality rate related to hypoxemia since pulse oximetry became accepted and used as a monitoring standard; it also helps in preventing anesthetic related morbidity and mortality; history shows that the acceptance of pulse oximetry as one of the standards for basic intra-operative monitoring is of great benefit.