Vasopressor use, peripheral vascular disease hypothermia, hypotension, intravascular injection of dyes and hemoglobinophathies can all contribute to inaccurate arterial saturation readings by pulse oximetry 3,4, most of which are interpreted as falsely low readings. Click to see full answer.
What can cause false readings on a pulse oximeter?
" (1) Carboxyhemoglobin gives a false high reading, (2) methemoglobinemia gives a false low reading (3) low oxygen saturations (the pulse oximeter is inaccurate), (4) excessive room ambient light, or overhead infrared lights, (5) tremors or vibrations of the patient. (6) methylene blue dye. (7) venous pulsations.
What are the limitations of a pulse oximeter?
A pulse oximeter is a valuable tool, but it has limitations. Anything that may hinder circulation to the limb or location where the pulse oximetry sensor is located. Anything that spoils the circulation will give incorrect readings or no readings.
What can cause false oxygen saturation readings?
What causes false oxygen saturation readings? Vasopressor use, peripheral vascular disease hypothermia, hypotension, intravascular injection of dyes and hemoglobinophathies can all contribute to inaccurate arterial saturation readings by pulse oximetry 3,4, most of which are interpreted as falsely low readings. Click to see full answer.
Can a pulse oximeter be used for hypothermia?
Pulse oximeters cannot be used for patients with hypothermia or vasoconstriction or hypotension due to vasopressor therapy. Incorrect pulse oximetry readings can be caused by other fluorescent lines or infrared rays (such as infrared rays used to keep young babies warm), or caused by the movement of the safety probe's limbs.
What does a pulse oximeter read?
Pulse oximeters read the percentage of hemoglobin with oxygen attached in your blood. Carbon monoxide bonds to the hemoglobin as well and the oximeter reads it the same as oxygen.. Oximeters can’t tell the difference between oxygen and carbon monoxide when bound to the hemoglobin.
What does saturation percent mean?
It stands for "Saturation Percentage of Oxygen", and measures the amount of hemoglobin (the protein found on red blood cells that carries oxygen and carbon dioxide to and from cells), that is actually bound to oxygen. This is a figure that changes from second to second, as respiration happens at the cellular level.
What is the best spO2 reading?
For an adult in good health, the SpO2 reading should be between 95 and 100%. These values are percentages, indicating what percentage of the hemoglobin is “filled up” with oxygen. Visualize the hemoglobin in your red blood cells as small cups. As these small cups return to the lungs they are about 3/4 “full” of oxygen.
How long does it take to get a pulse reading?
If you count your pulse for a full minute, you get a reading. If there is a brief innocuous variation it would be averaged out. If you do it for 15 seconds, your reading could be off by 4, if for 6 seconds, could be off by 10.
How long do you have to sit at one place before taking a pulse oximeter?
The pulse oximeter’s reading can be false at times, so you must sit at one place for at least 10 minutes before taking the reading.
What does a reading in a walking program mean?
Readings in that range indicate that you might be deconditioned and you should at least start a walking program. If you are on a walking program, then a monitor might be of use to see that your heart is within the desired training range, that you are working at the appropriate level. That is the purpose of a monitor.
What is the average blood pressure reading for a young person?
An average healthy young person, male or female, will have a reading ranging from 99 to 97% consistently. By mid-life or with a few accumulative diagnoses, it may range from about 96 to 93% or so. They would occasionally be short of breath with exertion but would recover fairly quickly with rest.
Causes of low pulse oximetry reading
One of the causes is hypoxemia, it occurs when oxygen levels in the blood are lower than normal. If the oxygen levels in your blood are too low, your body may not work properly.
Pulse oximeter false low reading
When taking measurements with the pulse oximeter, pay attention to whether the oxygen level is lower than previous measurements or is decreasing over time.
SpO2 normal range by age chart
This reading chart provides guidance on what oxygen level means and when and how to seek medical help.
How does an oximeter work?
When taking your oxygen readings, the pulse oximeter probe is clipped to your finger and begins emitting a low infrared light. This light penetrates the skin and counts the number of oxygenated blood cells flowing through your veins ( Page, 2017 ). However, bright ambient lighting in your immediate environment can dilute the infrared rays and make it more likely for the sensor to give an incorrect reading. Therefore, it’s recommended that you avoid taking your SpO2 levels near highly saturated lighting sources.
How does pulse oximetry help?
For the first time, we could accurately interpret an individual’s oxygen saturation and further assist them in treating their respiratory ailments. Over the decades, many patients have even used these sensors in their own homes. But even the most accurate pieces of equipment can be influenced by certain environmental and physiological conditions, and the pulse oximeter is no exception. These are some of the factors that affect pulse oximeter readings and how you can mitigate them when taking measurements in your home.
What can affect pulse oximeter readings?
The accessories you wear on your fingers can be an additional factor that affects pulse oximeter readings—namely, fake fingernails or thick nail polish. These materials can reflect light back into the sensor while the device is still running, which stops it from fully penetrating the finger. As such, you must remove these products for your sensor to work properly.
Why is it important to sit in a resting position when taking blood pressure readings?
Increased amounts of movement during the testing period can also speed up your blood flow and make it harder to find an accurate measurement . For this reason, it’s recommended that you sit in a resting position when taking your readings and avoid moving around while the device is running.
Can you wear a pressure cuff on your wrist?
For the device to accurately count the number of oxygenized blood cells, you must have unrestricted blood flow through that area. As such, you should never wear a pressure cuff or other accessories on the same arm you take your reading from.
