Doctors point out common mistakes when F0 measures SpO2 at home

According to statistics, about 5-10% of F0 may experience silent hypoxemia, meaning there is no feeling of shortness of breath but the blood oxygen saturation (SpO2) is reduced. This hinders the early detection of serious illness. Therefore, daily monitoring of SpO2 index is very necessary forCovid-19 patient.

What SpO2 level should be reported to medical staff?

According to the instructions of the health sector, the steps to accurately measure blood oxygen saturation (SpO2) include:

Step 1: Press the power button to check if the device emits infrared light, if the screen displays, if there is any battery left, if the battery is dead, you need to replace the battery or charge the battery (depending on the device type).

Step 2: Open the clamp, place your finger in the clamp slot so that the tip of your finger touches the end of the machine. Note that you must not wear nail polish, fake nails or cosmetics on the finger being measured. Make sure your nails are not too long, so that the tip of your finger can cover the sensor in the narrow slot.

Step 3: Turn on the device by pressing the power button. Do not move your hand while measuring. The measurement result will be displayed on the screen after a few seconds.

Step 4: When the measurement is finished, remove your finger, after a few seconds the device will automatically turn off. SpO2 will be displayed as a number in the position where the word SpO2 is written. The unit of measurement is percentage (%). Measurement range: 0-100%. Normal value: 96-100%.

Pulse rate will be displayed as a number in the heart position or in the PR position. Unit of measurement: beats/minute. Measurement range: 0-254 beats/minute. Normal value: 60-90 beats/minute (for adults, at rest).

A type of SpO2 measuring device on the market. Illustration photo

The Ministry of Health said that if SpO2 > 96%, F0 is classified as mild. SpO2 94-96% is moderate, SpO2 < 94% is severe (however, the classification of disease severity based on SpO2 index must be based on clinical symptoms such as respiratory failure, circulatory failure...)

For F0 treated at home, the Ministry of Health recommends that when SpO2 ≤ 96%, it is necessary to immediately notify the facility managing people with Covid-19 at home; commune or ward health stations; or mobile health stations, emergency transport centers... for timely handling (in case of detecting an abnormal SpO2 index, it is necessary to measure again after 30 seconds to 1 minute, when measuring, it is required to keep the measuring position still).

Mistakes when measuring SpO2 at home

While consulting Covid-19 patients for treatment at home, Dr. Hoang Tuan Thanh, Central Hospital for Tropical Diseases, encountered many cases of incorrect SpO2 measurement results due to a number of reasons.

According to Dr. Thanh, one of the problems that F0 often encounter is buying the wrong device, buying a fake or poor quality machine.

“There was one case where the SpO2 measured on their machine was 98%. However, this F0 showed signs of difficulty breathing, labored breathing, and shortness of breath. When admitted to the hospital, we measured the patient with a specialized measuring device and the SpO2 index was only 90% (while on the patient's personal machine it was still 98%). Thus, the measurement result was seriously incorrect,” Dr. Thanh shared.

Doctors recommend that people should research carefully and only buy devices that have been licensed for circulation, have clear origins, and have quality inspection certificates. They should not buy floating products of unknown origin (note that machines that are too cheap, only a few tens of thousands of dong, cannot be quality-assured devices).

Second, with F0 subjects being children, if the child moves and moves his or her arms and legs continuously while measuring SpO2, the accuracy will also be poor. In fact, Dr. Thanh has consulted many cases where children do not have respiratory failure but due to movement during the measurement process, the index is only about 85-86%, making the family very worried. The doctor said that to get the most accurate results, parents can measure SpO2 when the child is resting, such as when sleeping.

Note, many F0s have fever or hypothermia, hypotension (diseases that cause peripheral vasoconstriction), blood diseases (such as anemia, abnormal Hemoglobin...), SpO2 measurement will be difficult and inaccurate.

In addition, not letting the fingertips touch the end of the device, painting nails, etc. can also affect the measurement results. Therefore, patients should cut their nails before measuring, do not paint their nails. In case the device cannot be clamped on the finger, the patient can clamp it on the toe.

Regarding the number of times SpO2 is measured per day, Dr. Hoang Tuan Thanh said that mild Covid-19 patients can measure 2-3 times/day. However, if F0 starts to have more symptoms, with signs of suspected pneumonia such as rapid breathing, labored breathing (difficulty breathing, chest retraction, flaring of the nostrils), the number of measurements should be increased, possibly 3-4 times or whenever there are unusual signs to detect severe conditions early and go to the hospital promptly.

The doctor also said that F0 needs to pay attention to another important index displayed on the SpO2 meter, which is the pulse. This index in normal people is 60-90.

“In some F0s, even though the SpO2 measurement result is 99%, an increased pulse (>120 beats/minute) or decreased pulse (<50) can also be a sign that the disease is getting worse. Of course, the pulse index also depends on many factors such as fever, after strenuous exercise, after drinking coffee, beer, alcohol... Therefore, patients need to measure while resting, and consult a doctor if the pulse index is not within the normal range,” the doctor informed.