Pulse oximeter: why you need it and how to use it correctly

– a technique for determining saturation, or the level of oxygen saturation of hemoglobin in the blood.
This is a vital indicator that ensures the normal functioning of the cells and tissues of the body. During coronavirus, saturation levels can rapidly decrease due to pneumonia, so it is important to keep a record of the measurement results. A pulse oximeter
is a small device that is easy to use at home. In our store you can choose an option for any budget to always keep your own health under control.

• Description of pulse oximeters
• Operating principle of a pulse oximeter
• Indications for use of the device
• Application for Covid-19
• Who is recommended to use
• Details for instructions for use
• How to understand pulse oximeter readings
• Recommendations for choosing a heart rate monitor
• How to check the operation of the device

Description of pulse oximeters

Portable pulse oximeters resemble a small clothespin that fits onto your finger. They simultaneously measure two vital signs: pulse and saturation. The measurement methods are non-invasive, that is, they do not require skin puncture, blood sampling or other painful procedures. The device runs on batteries and can be stored in a home medicine cabinet. There are several types of similar devices, and it is worth familiarizing yourself with each of them before purchasing.

A clip-on pulse oximeter is the most common option and is suitable for use in hospitals and at home. You can purchase such a device in our store and use it according to the instructions. For professional use, you can also find pulse oximeters for round-the-clock monitoring of saturation levels. They are also attached to the finger, but a cord extends from them to a bracelet located on the wrist. The indicators are constantly displayed on a small monitor. There is also professional-sized equipment that is used during the treatment of patients with lung diseases in a hospital.

How to measure saturation correctly

Measuring saturation at home is quite simple. To do this, place your finger in the clamp or sleeve of the pulse oximeter. It is important that the device does not dangle, but is well fixed on the finger. After pressing the button on the instrument panel, the result appears on the screen after 15 - 30 seconds.

Important! Measurement results may be incorrect or completely absent if:

• The device dangles freely on your finger and slides off it. As practice shows, it is best to take measurements on the index, middle or ring fingers. In this case, it is desirable that the nails are cut short. Sometimes the length of the nails does not allow the pulse oximeter to be firmly fixed on the finger, which is why the readings may be distorted.
• The device is not secured correctly . The fingertip is an ideal place to measure peripheral saturation, and the readings here are most reliable for interpreting the absence or presence of hypoxia (oxygen starvation). In some cases, if it is impossible to measure saturation on the fingers, it is permissible to attach the pulse oximeter to the earlobe or toe (mainly in newborns).
• The nails are coated with varnish or gel polish . Since the operating principle of a pulse oximeter is based on shining the fingertip with infrared light and reading the results obtained with a special sensor, the coating on the nails makes this process difficult. And coating with gel polish makes it completely impossible. The stream of infrared rays simply “does not penetrate” a fashionable manicure. Therefore, to obtain reliable results, nails must be clean and uncoated, preferably of any kind.
• The device was purchased without documents confirming its reliability and safety..

Operating principle of a pulse oximeter

To understand the principle of operation of the device, it is important to understand what quantity it measures. Saturation is the degree to which hemoglobin in the blood is saturated with oxygen. During breathing, gas exchange occurs in the lungs. Arterial blood receives oxygen to carry it to organs and tissues. This gas is attached to a special protein, hemoglobin, which is found on red blood cells. Hemoglobin that contains oxygen is called saturated or saturated.

In the arterial blood of a healthy person, the saturation rate ranges from 96 to 100%. If you examine venous blood, the normal value will be about 75%. This is due to the fact that the blood releases some oxygen to the body's cells and then returns back to the lungs. If arterial blood saturation decreases to 94%, this indicates an acute or chronic course of dangerous lung diseases. When hemoglobin oxygen saturation decreases to 92–93% or lower, this indicates a dangerous state of hypoxia and the need for urgent hospitalization.

A pulse oximeter is a device for measuring saturation levels. It is very compact, so it is suitable for use at home, in the office, on the road and in any other conditions. It consists of several parts:

• a diode that emits light;
• light-sensitive sensor – located on the back of the finger during measurement;
• monitor on which the result will be displayed.

To determine the level of saturation, the diode emits light that completely illuminates the finger. The principle of operation of the device is the ability of saturated and unsaturated hemoglobin to absorb light. The sensor, which is located on the reverse side, detects the residual amount of light and analyzes this data. The amount of saturated hemoglobin bound to oxygen is displayed on the screen.

What the study shows

Pulse oximetry is performed to determine vital signs:

• Pulse rate. This indicator shows the heart rate, but it does not always coincide 100% with it. Sometimes there are differences between the readings of a pulse oximeter and an electrocardiograph. This feature is explained by partial absorption of pulsation by the walls of blood vessels, different elasticity of blood vessels, and blockage of the lumen.
• Saturation. This term refers to the saturation of blood with oxygen. The indicator under consideration indicates disturbances in cardiac activity and breathing immediately, before the following signs of oxygen deficiency appear: blueness of the skin, mucous membranes, change in heart rhythm.

Indications for use of the device

Pulse oximetry is a diagnostic area that is informative for various diseases of the respiratory system. To assess the patient's condition and the degree of hypoxia (oxygen starvation) of tissues, the saturation level is measured. Pulse oximeters are also necessary for diagnosis and during treatment of coronavirus, which occurs with pneumonia. In addition, these measurements can be informative in the following areas:

• during oxygen therapy, to assess its effectiveness;
• during anesthesia and operations, as well as during rehabilitation;
• in neonatology, especially for examining premature babies;
• for chronic heart failure;
• with proven apnea (stopping breathing) during sleep;
• with congenital and acquired heart defects.

Patients with chronic diseases that can cause hypoxia should purchase a pocket pulse oximeter and keep it in a portable first aid kit. The measurements will be informative and will allow you to quickly determine the deterioration of your health, since the device shows data at the time of use. If you carry out the procedure daily, you can monitor the dynamics of indicators and choose more effective treatment.

Application for Covid-19

Coronavirus

– a dangerous disease that occurs primarily in the lungs.
The inflammatory process leads to a deterioration in gas exchange, so the blood is not saturated with sufficient oxygen. In addition, the damaged areas undergo fibrosis over time and are gradually replaced by low-functional connective tissue. A decrease in saturation to 91% or lower is one of the characteristic signs of a coronavirus infection, which occurs in moderate or severe form. It is recommended to measure this indicator when the following symptoms appear:

• pallor of the skin and mucous membranes;
• weakness, dizziness, especially with sudden movements;
• wheezing in the lungs, cough, fever;
• deterioration of sense of smell;
• rapid heartbeat, uneven pulse, possible fainting.

A pulse oximeter must be in the home medicine cabinet for people at risk: the elderly, patients with chronic diseases of the cardiovascular and respiratory systems, as well as other internal organs. With its help, you can promptly identify dangerous oxygen metabolism disorders and seek medical help.

In addition, the device should definitely be used in the post-coronavirus period, during rehabilitation. Inflammatory processes, high temperature, general weakness and decreased immunity lead to the fact that tissues are restored slowly. Foci of fibrosis form in the lungs - islands of connective tissue that cannot participate in the breathing process. Despite the fact that the virus can be removed from the body, the patient continues to experience symptoms of oxygen starvation if the healthy surface of the lungs does not have time to saturate hemoglobin with oxygen to the required extent.

Is there a risk of not properly monitoring oxygen levels at home?

It is possible that home monitoring may give incorrect readings or be used incorrectly, leading the patient to seek help unnecessarily. If you or someone in your home is diagnosed with very low readings, you can test your device on a healthy person to make sure it is working properly and discuss this with your doctor. And home monitoring shouldn't lull you into a false sense of security. Don't ignore physical symptoms, even if your oxygen levels are normal. You should still call your doctor if you have severe shortness of breath, fever, confusion, or any other symptom. The benefit of monitoring is that it can potentially detect deteriorating airway health before you even notice it.

Who is recommended to use

Portable Pulse Oximeter

- This is a device for home use.
It is suitable for any person who cares about their own health and wants to know all the important indicators. During the coronavirus pandemic, a pulse oximeter remains one of the most useful purchases for use at home. The procedure is simple and painless, and even a beginner can understand the instructions for the device. However, regular measurements are necessary for the following populations:

• people who are at risk of coronavirus;
• for acute and chronic diseases of the cardiovascular system;
• with abnormal development of the heart or blood vessels;
• for various disorders of the respiratory system;
• during the recovery period after surgery;
• during rehabilitation after suffering from coronavirus.

It is important to understand that patients with various diseases that can cause a decrease in saturation need to receive accurate data. To do this, it is worth choosing a high-quality device that will record all changes and produce results without failure. One pulse oximeter is enough to measure the saturation level and pulse of the whole family. For children, you can choose special children's devices - they fit well in size, so they more accurately record the necessary data.

Pulse oximeters are also useful for athletes during training. During classes, oxygen that is in the tissues is rapidly burned, as the muscles experience increased stress. This can lead to a sharp decrease in saturation and deterioration in well-being. During this period, the athlete feels dizziness, weakness and other signs of oxygen starvation. The presence of a compact device will allow you to quickly determine the cause of poor health and select loads in accordance with the physical capabilities of the person.

Why can pulse oximetry data be misleading?

It is important to understand that the result of pulse oximetry can be influenced by: the sensitivity of the device (including battery charge), lighting, and the color of the patient’s skin (the darker, the higher the indicator, which does not reflect the real state of affairs).

The concept of “saturation rate” is very arbitrary. It happens that patients with signs of coronavirus infection and a mobile non-invasive device for measuring saturation begin to panic and call an ambulance if the oxygen in the blood drops, for example, to 93%. To do this, let’s look at the data from the conditional norm table:

Details for instructions for use

Each pulse oximeter package contains the necessary documentation, including instructions for use. It is not difficult to understand, since the device is compact and simple. Most home pulse oximeters run on AA batteries or rechargeable batteries. To use the device, you must insert the batteries and wait a few minutes. Then you should pay attention to the device's charge level - if it is low, the readings may not be accurate enough. Next, you just need to follow a few simple steps yourself or with an assistant.

1. The first step is to take a stationary position, sitting or lying down, with your arm supported. It is recommended to remain in this position for several minutes before measuring to obtain more accurate readings.
2. The second step is to place your finger in the special hole of the pulse oximeter. It must be clean and free of nail polish and other coatings that could affect the measurement result. The sensor will operate for 20–30 seconds, depending on the model of the device, and during this time the finger must remain motionless.
3. When the results are displayed on the monitor, the measurements are completed. It is recommended to record the data in order to keep a constant record of heart rate and saturation levels. After this, the pulse oximeter should be turned off and placed in a box to keep it away from sunlight and dust.

The device can be used independently or with an assistant. Even simple portable pulse oximeters can measure pulse and saturation in bedridden patients, as well as during sleep. For longer measurements, it is recommended to use instruments that continuously read data and display it on the screen. The monitor is attached to the wrist, and the data is accurate even if you do not hold your finger in a stationary position. These pulse oximeters are effective for diagnosing sleep apnea and for monitoring heart rate and saturation levels around the clock.

How to understand pulse oximeter readings

As a result of the measurement, all data is displayed on the monitor screen. The first indicator that a pulse oximeter reads is the pulse. It is displayed in the number of heartbeats per minute. In an adult, the normal pulse ranges from 60 to 90 beats per minute. It can increase after physical exertion, with chronic diseases of the heart and blood vessels, and also as a result of a sharp decrease in oxygen levels in the blood. The pulse is not a constant value and can change frequently, so to obtain more accurate data it is recommended to measure it several times at intervals of 3-4 minutes.

The second indicator for which portable pulse oximeters are used is saturation (SpO2). It is displayed as a percentage and indicates the level of oxygenated hemoglobin. In a healthy person at rest, it will correspond to 95% or more. However, if the monitor displays a result of 98–100%, it is worth repeating the procedure - the device may be faulty. The saturation level from 90 to 94% corresponds to 1 degree of hypoxia, from 75 to 89% - 2 degrees, from 60 to 75% - 3 degrees. When saturation decreases to 60%, hypoxic coma is observed, which poses a danger to the patient’s life. It is recommended to consult a doctor if the monitor displays a saturation level of 94% or lower - even minor oxygen deprivation can significantly affect the functioning of internal organs and tissues.

Features of the device

The pulse oximeter passes light waves of different lengths through the tip of your finger (this is painless). The waves are “targeted” at hemoglobin, a protein molecule in the blood that carries oxygen through the vascular bed.

The device functions better on warm hands than on cold hands. And because oxygen levels can fluctuate, measurements need to be taken several times throughout the day. Measurements should also be taken in various conditions, for example, lying on your back or after walking.

Recommendations for choosing a pulse oximeter

There is a place in any home medicine cabinet for a portable pulse oximeter. Our store offers a wide range of devices that can be used at home. They are offered with all the necessary documents and quality certificates, so they are suitable for use at home and in medical institutions. Doctors have several criteria by which they recommend choosing a pulse oximeter.

1. Type of device – a simple clip-on pulse oximeter is suitable for home use. If there is a need to purchase a specific device with memory fixation, round-the-clock measurement, removable parts and other additional functions, you can find out about this from your doctor. If there are no indications, the simplest reusable model is sufficient.
2. Having a license is a prerequisite. A device for measuring vital signs must be registered as a medical device. This can be checked by entering the pulse oximeter number in the state register on the website.
3. A guarantee from the manufacturer is an opportunity to exchange a product or get a refund if it turns out to be damaged or does not provide accurate indicators. This can be checked after receiving the device, especially when ordering online.

The cost of a pulse oximeter is one of the important selection criteria. You should not buy the most affordable devices if you need to use them constantly. However, devices from the mid-price category usually capture all the necessary indicators well, so the measurements can be trusted. Expensive pulse oximeters with additional functions are more durable. They work even after exposure to the sun and other adverse conditions. However, for home use it is not necessary to choose the most expensive and difficult to use device.