Pulse oximeter how to read?

Pulse oximetry is a way to measure the amount of oxygen carried by the blood. By using a small device called a pulse oximeter, the level of oxygen in the blood can be monitored without the need to prick with a needle.

The level of oxygen in the blood measured with an oximeter is called the oxygen saturation level. This is a percentage of the amount of oxygen your blood carries compared to the maximum it is capable of carrying.

Normally, more than 89% of your red blood must carry oxygen.

What are normal blood oxygen levels?

Why is it important to have my blood oxygen level checked?

If you have lung disease, your blood oxygen level may be lower than normal. This is important to know because when your oxygen level is low, your body’s cells can have a hard time working properly.

Oxygen is the “gas” that makes your body “work,” and if you have little “gas,” your body is not working properly.

Having a very low blood oxygen level can also put pressure on your heart and brain.

Most people need an oxygen saturation level of at least 89% to keep their cells healthy. Having an oxygen level lower than this for a short period of time is not believed to cause harm.

However, your cells can be strained or damaged if low oxygen levels occur many times. If your oxygen level is low in the room air, you may be asked to use supplemental (extra) oxygen.

The oximeter can be used to help see how much oxygen you need and when you may need it.

For example, some people need more oxygen when they are asleep than when they are awake. Some need more oxygen with activity than when they are at rest.

How does a home pulse oximeter work?

A pulse oximeter comes as a small unit with an integrated finger and toe clip, or as a small handheld device that has a wire probe that can be attached or applied to your finger, toe, or earlobe.

The small unit is less expensive and more practical for home use.

Light rays from the device pass through the blood in your finger (ear or foot lobe) to measure its oxygen.

You will not feel this happening. Light rays are “read” to calculate the percentage of your blood that carries oxygen. It also provides a reading of your heart rate (pulse).

To make sure the oximeter is giving you a good reading, count your pulse for one minute and compare the number you get to the pulse number on the oximeter. If they are the same, you are getting a good signal.

Oxygen level chart for adults

Most people do not need a pulse oximeter. Some people have prescribed a pulse oximeter if they have or could have periods of low oxygen; for example, when you exercise or are traveling at high altitudes.

Having a pulse oximeter in these cases will allow you to monitor your blood oxygen level and know when you need to increase your supplemental oxygen flow rate.

Ask your designated healthcare worker what oxygen saturation number they want you to maintain.

Pulse oximeters are available online or by prescription from your local pharmacy or medical supply company. In some cases, your insurance company will cover the cost of a pulse oximeter.

Pulse oximetry vs arterial blood gas

What is the difference between the oxygen information provided by an oximeter and an arterial blood gas?

An oximeter indirectly measures the amount of oxygen carried by the blood.

An arterial blood gas directly measures both the amount of oxygen carried by the blood and the actual amount of gases (oxygen and carbon dioxide) in the blood.

To obtain an arterial blood gas, blood is drawn directly from the artery and can be painful. Oximetry is painless but not as accurate as an arterial blood gas. Also, a pulse oximeter does not measure your carbon dioxide level.

Pulse oximetry accuracy range

How accurate are pulse oximeters?

The oxygen level of a pulse oximeter is reasonably accurate.

Most oximeters give a reading 2% above or 2% below what your saturation would be if it were obtained by arterial blood gas.

For example, if your oxygen saturation reads 92% on the pulse oximeter, it may actually be between 90 and 94%.

The oximeter reading may be less accurate if a person wears nail polish, artificial nails have cold hands, or poor circulation. Nail polish only affects readings if the sensor is placed over polish.

See that the sensor is at the base of the nail. If the artificial nails are too long, you may need to cut the nail shorter, try laying the probe on its side, or try using a toe.

A pulse oximeter can also be less accurate with very low oxygen saturation levels (below 80%) or with very dark skin.

When do you use a pulse oximeter?

If your healthcare provider has prescribed an oximeter, ask them when they want you to use the oximeter to check your blood oxygen level. Ask your healthcare provider when to change your supplemental oxygen flow rate and what reading to seek medical attention.

What is the correct way to use a pulse oximeter?

best way to use a pulse oximeter. Times, when an oximeter reading can be helpful, are:

• When you are first prescribed oxygen
  • This helps your healthcare provider know if your oxygen saturation levels change and how they change when you are doing activities around the house.
• During or just after exercise.
  • Your body, like your car, needs more oxygen (“gas”) when you are in motion.
  • Your oxygen saturation may be monitored during activity to see if you are low on oxygen, which may not be a problem at rest.
  • Your healthcare provider will decide with you what to do if you have oxygen problems with exercise.
• If you are flying or traveling to a high-altitude location, your supplemental oxygen needs may increase during these times.

How to read a pulse oximeter?

How can I get the best reading from my pulse oximeter?

Your pulse oximeter measures your oxygen saturation or the percentage of blood that carries oxygen.

To get the best reading from your oximeter, you must ensure that enough blood is flowing to your hand and finger wearing the device.

• Therefore, the best reading is achieved when your hand is warm, relaxed, and below the level of your heart.
• If you smoke, unfortunately your oximeter reading may be higher than your actual oxygen saturation.
• This is because smoking increases the levels of carbon monoxide in the blood and the oximeter cannot differentiate between carbon monoxide gas and oxygen.
• If you smoke, talk to your healthcare provider about how to read the numbers on your oximeter correctly.
• In addition to the inaccurate readings described above, you can sometimes get abnormal readings from your oximeter because the oximeter probe is not working properly.
• You can take your oximeter to your healthcare provider’s office or equipment company to have it checked against theirs to verify its accuracy.

Best pulse oximeter for an accurate reading

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Pulse Oximeters: Answering Your Frequently Asked Questions