There are questions that may arise on your minds of what does a pulse oximeter really does for us. It is therefore, monitoring the oxygenation levels of a patient's blood. It works by a sensor which is usually placed on a fingertip or earlobe, or on the foot of an infant. Then, it measures the oxygenation levels by passing infrared wavelengths back and forth.
When a patient’s oxygenation is unstable, then they are to use an oximeter. It is mostly used in intensive care units, emergency rooms, and critical care departments. However, there are misconceptions on the usage of oximeter. It never measures ventilation, metabolism of oxygen, or all levels of blood gases, it only determines the amount of oxygen contained in the blood.
In addition, oximeters can also help detect blood loss by applying an algorithm that converts the absorption changes to blood volume estimates. A person’s oxygen level varies depending on many things. Few of the reasons are: smoking, drugs, exercising, swimming, and others. It is not a thing to be worried on if your oxygen level is not 100%. Because only few people reaches oxygen level that high.
To use a pulse oximeter requires enough knowledge and practice. Because as you are doing such, you may experience false low readings and false high readings. The causes of falsely low pulse oximeter readings involve hypo perfusion of the sensored extremity, inappropriate application of the sensor, calloused skin, and extraneous movement. These can possibly let the health personnel treat the patient for hypoxemia, well in fact, not necessarily.
The purpose of a pulse oximeter is affected by many variables, including: ambient light; shivering; abnormal hemoglobin; pulse rate and rhythm; vasoconstriction and cardiac function. A pulse oximeter gives no indication of a patient's ventilation, only of their oxygenation, and thus can give a false sense of security if supplemental oxygen is being given.
Moreover, there may be a delay between the occurrence of a potentially hypoxic event such as respiratory obstruction and an oximeter detecting low oxygen saturation. However, oximetry is a useful non-invasive monitor of a patient's cardio-respiratory system, which has undoubtedly improved patient protection in many circumstances.
A false high reading on the oximeter on the other hand is caused if the hemoglobin is bound to something else besides oxygen, or if the patient has carbon monoxide or cyanide poisoning. This pulse oximeter false reading can mask signs of hypoxemia, which is a potentially dangerous condition to have.